# rsync

## NAME



           rsync - a fast, versatile, remote (and local) file-copying tool
    


## SYNOPSIS



           Local:
               rsync [OPTION...] SRC... [DEST]
    
           Access via remote shell:
               Pull:
                   rsync [OPTION...] [USER@]HOST:SRC... [DEST]
               Push:
                   rsync [OPTION...] SRC... [USER@]HOST:DEST
    
           Access via rsync daemon:
               Pull:
                   rsync [OPTION...] [USER@]HOST::SRC... [DEST]
                   rsync [OPTION...] rsync://[USER@]HOST[:PORT]/SRC... [DEST]
               Push:
                   rsync [OPTION...] SRC... [USER@]HOST::DEST
                   rsync [OPTION...] SRC... rsync://[USER@]HOST[:PORT]/DEST)
    
           Usages with just one SRC arg and no DEST arg will list the source
           files instead of copying.
    
           The online version of this manpage (that includes cross-linking of
           topics) is available at 
           ⟨https://download.samba.org/pub/rsync/rsync.1⟩.
    


## DESCRIPTION



           Rsync is a fast and extraordinarily versatile file copying tool.
           It can copy locally, to/from another host over any remote shell,
           or to/from a remote rsync daemon.  It offers a large number of
           options that control every aspect of its behavior and permit very
           flexible specification of the set of files to be copied.  It is
           famous for its delta-transfer algorithm, which reduces the amount
           of data sent over the network by sending only the differences
           between the source files and the existing files in the
           destination.  Rsync is widely used for backups and mirroring and
           as an improved copy command for everyday use.
    
           Rsync finds files that need to be transferred using a "quick
           check" algorithm (by default) that looks for files that have
           changed in size or in last-modified time.  Any changes in the
           other preserved attributes (as requested by options) are made on
           the destination file directly when the quick check indicates that
           the file's data does not need to be updated.
    
           Some of the additional features of rsync are:
    
           o      support for copying links, devices, owners, groups, and
                  permissions
    
           o      exclude and exclude-from options similar to GNU tar
    
           o      a CVS exclude mode for ignoring the same files that CVS
                  would ignore
    
           o      can use any transparent remote shell, including ssh or rsh
    
           o      does not require super-user privileges
    
           o      pipelining of file transfers to minimize latency costs
    
           o      support for anonymous or authenticated rsync daemons (ideal
                  for mirroring)
    


## GENERAL



           Rsync copies files either to or from a remote host, or locally on
           the current host (it does not support copying files between two
           remote hosts).
    
           There are two different ways for rsync to contact a remote system:
           using a remote-shell program as the transport (such as ssh or rsh)
           or contacting an rsync daemon directly via TCP.  The remote-shell
           transport is used whenever the source or destination path contains
           a single colon (:) separator after a host specification.
           Contacting an rsync daemon directly happens when the source or
           destination path contains a double colon (::) separator after a
           host specification, OR when an rsync:// URL is specified (see also
           the USING RSYNC-DAEMON FEATURES VIA A REMOTE-SHELL CONNECTION
           section for an exception to this latter rule).
    
           As a special case, if a single source arg is specified without a
           destination, the files are listed in an output format similar to
           "**ls -l** ".
    
           As expected, if neither the source or destination path specify a
           remote host, the copy occurs locally (see also the **--list-only**
           option).
    
           Rsync refers to the local side as the client and the remote side
           as the server.  Don't confuse server with an rsync daemon.  A
           daemon is always a server, but a server can be either a daemon or
           a remote-shell spawned process.
    


## SETUP



           See the file README.md for installation instructions.
    
           Once installed, you can use rsync to any machine that you can
           access via a remote shell (as well as some that you can access
           using the rsync daemon-mode protocol).  For remote transfers, a
           modern rsync uses ssh for its communications, but it may have been
           configured to use a different remote shell by default, such as rsh
           or remsh.
    
           You can also specify any remote shell you like, either by using
           the **-e** command line option, or by setting the **RSYNC_RSH**
           environment variable.
    
           Note that rsync must be installed on both the source and
           destination machines.
    


## USAGE



           You use rsync in the same way you use rcp.  You must specify a
           source and a destination, one of which may be remote.
    
           Perhaps the best way to explain the syntax is with some examples:
    
               rsync -t *.c foo:src/
    
           This would transfer all files matching the pattern ***.c** from the
           current directory to the directory src on the machine foo.  If any
           of the files already exist on the remote system then the rsync
           remote-update protocol is used to update the file by sending only
           the differences in the data.  Note that the expansion of wildcards
           on the command-line (***.c**) into a list of files is handled by the
           shell before it runs rsync and not by rsync itself (exactly the
           same as all other Posix-style programs).
    
               rsync -avz foo:src/bar /data/tmp
    
           This would recursively transfer all files from the directory
           src/bar on the machine foo into the /data/tmp/bar directory on the
           local machine.  The files are transferred in archive mode, which
           ensures that symbolic links, devices, attributes, permissions,
           ownerships, etc. are preserved in the transfer.  Additionally,
           compression will be used to reduce the size of data portions of
           the transfer.
    
               rsync -avz foo:src/bar/ /data/tmp
    
           A trailing slash on the source changes this behavior to avoid
           creating an additional directory level at the destination.  You
           can think of a trailing / on a source as meaning "copy the
           contents of this directory" as opposed to "copy the directory by
           name", but in both cases the attributes of the containing
           directory are transferred to the containing directory on the
           destination.  In other words, each of the following commands
           copies the files in the same way, including their setting of the
           attributes of /dest/foo:
    
               rsync -av /src/foo /dest
               rsync -av /src/foo/ /dest/foo
    
           Note also that host and module references don't require a trailing
           slash to copy the contents of the default directory.  For example,
           both of these copy the remote directory's contents into "/dest":
    
               rsync -av host: /dest
               rsync -av host::module /dest
    
           You can also use rsync in local-only mode, where both the source
           and destination don't have a ':' in the name.  In this case it
           behaves like an improved copy command.
    
           Finally, you can list all the (listable) modules available from a
           particular rsync daemon by leaving off the module name:
    
               rsync somehost.mydomain.com::
    


## COPYING TO A DIFFERENT NAME



           When you want to copy a directory to a different name, use a
           trailing slash on the source directory to put the contents of the
           directory into any destination directory you like:
    
               rsync -ai foo/ bar/
    
           Rsync also has the ability to customize a destination file's name
           when copying a single item.  The rules for this are:
    
           o      The transfer list must consist of a single item (either a
                  file or an empty directory)
    
           o      The final element of the destination path must not exist as
                  a directory
    
           o      The destination path must not have been specified with a
                  trailing slash
    
           Under those circumstances, rsync will set the name of the
           destination's single item to the last element of the destination
           path.  Keep in mind that it is best to only use this idiom when
           copying a file and use the above trailing-slash idiom when copying
           a directory.
    
           The following example copies the **foo.c** file as **bar.c** in the **save**
           dir (assuming that **bar.c** isn't a directory):
    
               rsync -ai src/foo.c save/bar.c
    
           The single-item copy rule might accidentally bite you if you
           unknowingly copy a single item and specify a destination dir that
           doesn't exist (without using a trailing slash).  For example, if
           **src/*.c** matches one file and **save/dir** doesn't exist, this will
           confuse you by naming the destination file **save/dir** :
    
               rsync -ai src/*.c save/dir
    
           To prevent such an accident, either make sure the destination dir
           exists or specify the destination path with a trailing slash:
    
               rsync -ai src/*.c save/dir/
    


## SORTED TRANSFER ORDER



           Rsync always sorts the specified filenames into its internal
           transfer list.  This handles the merging together of the contents
           of identically named directories, makes it easy to remove
           duplicate filenames. It can, however, confuse someone when the
           files are transferred in a different order than what was given on
           the command-line.
    
           If you need a particular file to be transferred prior to another,
           either separate the files into different rsync calls, or consider
           using **--delay-updates**(which doesn't affect the sorted transfer
           order, but does make the final file-updating phase happen much
           more rapidly).
    


## MULTI-HOST SECURITY



           Rsync takes steps to ensure that the file requests that are shared
           in a transfer are protected against various security issues.  Most
           of the potential problems arise on the receiving side where rsync
           takes steps to ensure that the list of files being transferred
           remains within the bounds of what was requested.
    
           Toward this end, rsync 3.1.2 and later have aborted when a file
           list contains an absolute or relative path that tries to escape
           out of the top of the transfer.  Also, beginning with version
           3.2.5, rsync does two more safety checks of the file list to (1)
           ensure that no extra source arguments were added into the transfer
           other than those that the client requested and (2) ensure that the
           file list obeys the exclude rules that were sent to the sender.
    
           For those that don't yet have a 3.2.5 client rsync (or those that
           want to be extra careful), it is safest to do a copy into a
           dedicated destination directory for the remote files when you
           don't trust the remote host.  For example, instead of doing an
           rsync copy into your home directory:
    
               rsync -aiv host1:dir1 ~
    
           Dedicate a "host1-files" dir to the remote content:
    
               rsync -aiv host1:dir1 ~/host1-files
    
           See the **--trust-sender** option for additional details.
    
           CAUTION: it is not particularly safe to use rsync to copy files
           from a case-preserving filesystem to a case-ignoring filesystem.
           If you must perform such a copy, you should either disable
           symlinks via **--no-links** or enable the munging of symlinks via
           **--munge-links**(and make sure you use the right local or remote
           option).  This will prevent rsync from doing potentially dangerous
           things if a symlink name overlaps with a file or directory. It
           does not, however, ensure that you get a full copy of all the
           files (since that may not be possible when the names overlap). A
           potentially better solution is to list all the source files and
           create a safe list of filenames that you pass to the **--files-from**
           option.  Any files that conflict in name would need to be copied
           to different destination directories using more than one copy.
    
           While a copy of a case-ignoring filesystem to a case-ignoring
           filesystem can work out fairly well, if no **--delete-during** or
           **--delete-before** option is active, rsync can potentially update an
           existing file on the receiving side without noticing that the
           upper-/lower-case of the filename should be changed to match the
           sender.
    


## ADVANCED USAGE



           The syntax for requesting multiple files from a remote host is
           done by specifying additional remote-host args in the same style
           as the first, or with the hostname omitted.  For instance, all
           these work:
    
               rsync -aiv host:file1 :file2 host:file{3,4} /dest/
               rsync -aiv host::modname/file{1,2} host::modname/extra /dest/
               rsync -aiv host::modname/first ::extra-file{1,2} /dest/
    
           Note that a daemon connection only supports accessing one module
           per copy command, so if the start of a follow-up path doesn't
           begin with the modname of the first path, it is assumed to be a
           path in the module (such as the extra-file1 & extra-file2 that are
           grabbed above).
    
           Really old versions of rsync (2.6.9 and before) only allowed
           specifying one remote-source arg, so some people have instead
           relied on the remote-shell performing space splitting to break up
           an arg into multiple paths. Such unintuitive behavior is no longer
           supported by default (though you can request it, as described
           below).
    
           Starting in 3.2.4, filenames are passed to a remote shell in such
           a way as to preserve the characters you give it. Thus, if you ask
           for a file with spaces in the name, that's what the remote rsync
           looks for:
    
               rsync -aiv host:'a simple file.pdf' /dest/
    
           If you use scripts that have been written to manually apply extra
           quoting to the remote rsync args (or to require remote arg
           splitting), you can ask rsync to let your script handle the extra
           escaping.  This is done by either adding the **--old-args** option to
           the rsync runs in the script (which requires a new rsync) or
           exporting RSYNC_OLD_ARGS=1 and RSYNC_PROTECT_ARGS=0 (which works
           with old or new rsync versions).
    


## CONNECTING TO AN RSYNC DAEMON



           It is also possible to use rsync without a remote shell as the
           transport.  In this case you will directly connect to a remote
           rsync daemon, typically using TCP port 873. (This obviously
           requires the daemon to be running on the remote system, so refer
           to the STARTING AN RSYNC DAEMON TO ACCEPT CONNECTIONS section
           below for information on that.)
    
           Using rsync in this way is the same as using it with a remote
           shell except that:
    
           o      Use either double-colon syntax or rsync:// URL syntax
                  instead of the single-colon (remote shell) syntax.
    
           o      The first element of the "path" is actually a module name.
    
           o      Additional remote source args can use an abbreviated syntax
                  that omits the hostname and/or the module name, as
                  discussed in ADVANCED USAGE.
    
           o      The remote daemon may print a "message of the day" when you
                  connect.
    
           o      If you specify only the host (with no module or path) then
                  a list of accessible modules on the daemon is output.
    
           o      If you specify a remote source path but no destination, a
                  listing of the matching files on the remote daemon is
                  output.
    
           o      The **--rsh**(**-e**) option must be omitted to avoid changing the
                  connection style from using a socket connection to USING
                  RSYNC-DAEMON FEATURES VIA A REMOTE-SHELL CONNECTION.
    
           An example that copies all the files in a remote module named
           "src":
    
               rsync -av host::src /dest
    
           Some modules on the remote daemon may require authentication.  If
           so, you will receive a password prompt when you connect.  You can
           avoid the password prompt by setting the environment variable
           **RSYNC_PASSWORD** to the password you want to use or using the
           **--password-file** option.  This may be useful when scripting rsync.
    
           WARNING: On some systems environment variables are visible to all
           users.  On those systems using **--password-file** is recommended.
    
           You may establish the connection via a web proxy by setting the
           environment variable **RSYNC_PROXY** to a hostname:port pair pointing
           to your web proxy.  Note that your web proxy's configuration must
           support proxy connections to port 873.
    
           You may also establish a daemon connection using a program as a
           proxy by setting the environment variable **RSYNC_CONNECT_PROG** to
           the commands you wish to run in place of making a direct socket
           connection.  The string may contain the escape "%H" to represent
           the hostname specified in the rsync command (so use "%%" if you
           need a single "%" in your string).  For example:
    
               export RSYNC_CONNECT_PROG='ssh proxyhost nc %H 873'
               rsync -av targethost1::module/src/ /dest/
               rsync -av rsync://targethost2/module/src/ /dest/
    
           The command specified above uses ssh to run nc (netcat) on a
           proxyhost, which forwards all data to port 873 (the rsync daemon)
           on the targethost (%H).
    
           Note also that if the **RSYNC_SHELL** environment variable is set,
           that program will be used to run the **RSYNC_CONNECT_PROG** command
           instead of using the default shell of the **system()** call.
    


## USING RSYNC-DAEMON FEATURES VIA A REMOTE-SHELL CONNECTION



           It is sometimes useful to use various features of an rsync daemon
           (such as named modules) without actually allowing any new socket
           connections into a system (other than what is already required to
           allow remote-shell access).  Rsync supports connecting to a host
           using a remote shell and then spawning a single-use "daemon"
           server that expects to read its config file in the home dir of the
           remote user.  This can be useful if you want to encrypt a daemon-
           style transfer's data, but since the daemon is started up fresh by
           the remote user, you may not be able to use features such as
           chroot or change the uid used by the daemon. (For another way to
           encrypt a daemon transfer, consider using ssh to tunnel a local
           port to a remote machine and configure a normal rsync daemon on
           that remote host to only allow connections from "localhost".)
    
           From the user's perspective, a daemon transfer via a remote-shell
           connection uses nearly the same command-line syntax as a normal
           rsync-daemon transfer, with the only exception being that you must
           explicitly set the remote shell program on the command-line with
           the **--rsh=COMMAND** option. (Setting the RSYNC_RSH in the
           environment will not turn on this functionality.) For example:
    
               rsync -av --rsh=ssh host::module /dest
    
           If you need to specify a different remote-shell user, keep in mind
           that the user@ prefix in front of the host is specifying the
           rsync-user value (for a module that requires user-based
           authentication).  This means that you must give the '-l user'
           option to ssh when specifying the remote-shell, as in this example
           that uses the short version of the **--rsh** option:
    
               rsync -av -e "ssh -l ssh-user" rsync-user@host::module /dest
    
           The "ssh-user" will be used at the ssh level; the "rsync-user"
           will be used to log-in to the "module".
    
           In this setup, the daemon is started by the ssh command that is
           accessing the system (which can be forced via the
           **~/.ssh/authorized_keys** file, if desired).  However, when accessing
           a daemon directly, it needs to be started beforehand.
    


## STARTING AN RSYNC DAEMON TO ACCEPT CONNECTIONS



           In order to connect to an rsync daemon, the remote system needs to
           have a daemon already running (or it needs to have configured
           something like inetd to spawn an rsync daemon for incoming
           connections on a particular port).  For full information on how to
           start a daemon that will handling incoming socket connections, see
           the rsyncd.conf(5) manpage -- that is the config file for the
           daemon, and it contains the full details for how to run the daemon
           (including stand-alone and inetd configurations).
    
           If you're using one of the remote-shell transports for the
           transfer, there is no need to manually start an rsync daemon.
    


## EXAMPLES



           Here are some examples of how rsync can be used.
    
           To backup a home directory, which consists of large MS Word files
           and mail folders, a per-user cron job can be used that runs this
           each day:
    
               rsync -aiz . bkhost:backup/joe/
    
           To move some files from a remote host to the local host, you could
           run:
    
               rsync -aiv --remove-source-files rhost:/tmp/{file1,file2}.c ~/src/
    


## OPTION SUMMARY



           Here is a short summary of the options available in rsync.  Each
           option also has its own detailed description later in this
           manpage.
    
           --verbose, -v            increase verbosity
           --info=FLAGS             fine-grained informational verbosity
           --debug=FLAGS            fine-grained debug verbosity
           --stderr=e|a|c           change stderr output mode (default: errors)
           --quiet, -q              suppress non-error messages
           --no-motd                suppress daemon-mode MOTD
           --checksum, -c           skip based on checksum, not mod-time & size
           --archive, -a            archive mode is -rlptgoD (no -A,-X,-U,-N,-H)
           --no-OPTION              turn off an implied OPTION (e.g. --no-D)
           --recursive, -r          recurse into directories
           --relative, -R           use relative path names
           --no-implied-dirs        don't send implied dirs with --relative
           --backup, -b             make backups (see --suffix & --backup-dir)
           --backup-dir=DIR         make backups into hierarchy based in DIR
           --suffix=SUFFIX          backup suffix (default ~ w/o --backup-dir)
           --update, -u             skip files that are newer on the receiver
           --inplace                update destination files in-place
           --append                 append data onto shorter files
           --append-verify          --append w/old data in file checksum
           --dirs, -d               transfer directories without recursing
           --old-dirs, --old-d      works like --dirs when talking to old rsync
           --mkpath                 create destination's missing path components
           --links, -l              copy symlinks as symlinks
           --copy-links, -L         transform symlink into referent file/dir
           --copy-unsafe-links      only "unsafe" symlinks are transformed
           --safe-links             ignore symlinks that point outside the tree
           --munge-links            munge symlinks to make them safe & unusable
           --copy-dirlinks, -k      transform symlink to dir into referent dir
           --keep-dirlinks, -K      treat symlinked dir on receiver as dir
           --hard-links, -H         preserve hard links
           --perms, -p              preserve permissions
           --executability, -E      preserve executability
           --chmod=CHMOD            affect file and/or directory permissions
           --acls, -A               preserve ACLs (implies --perms)
           --xattrs, -X             preserve extended attributes
           --owner, -o              preserve owner (super-user only)
           --group, -g              preserve group
           --devices                preserve device files (super-user only)
           --copy-devices           copy device contents as a regular file
           --write-devices          write to devices as files (implies --inplace)
           --specials               preserve special files
           -D                       same as --devices --specials
           --times, -t              preserve modification times
           --atimes, -U             preserve access (use) times
           --open-noatime           avoid changing the atime on opened files
           --crtimes, -N            preserve create times (newness)
           --omit-dir-times, -O     omit directories from --times
           --omit-link-times, -J    omit symlinks from --times
           --super                  receiver attempts super-user activities
           --fake-super             store/recover privileged attrs using xattrs
           --sparse, -S             turn sequences of nulls into sparse blocks
           --preallocate            allocate dest files before writing them
           --dry-run, -n            perform a trial run with no changes made
           --whole-file, -W         copy files whole (w/o delta-xfer algorithm)
           --checksum-choice=STR    choose the checksum algorithm (aka --cc)
           --one-file-system, -x    don't cross filesystem boundaries
           --block-size=SIZE, -B    force a fixed checksum block-size
           --rsh=COMMAND, -e        specify the remote shell to use
           --rsync-path=PROGRAM     specify the rsync to run on remote machine
           --existing               skip creating new files on receiver
           --ignore-existing        skip updating files that exist on receiver
           --remove-source-files    sender removes synchronized files (non-dir)
           --del                    an alias for --delete-during
           --delete                 delete extraneous files from dest dirs
           --delete-before          receiver deletes before xfer, not during
           --delete-during          receiver deletes during the transfer
           --delete-delay           find deletions during, delete after
           --delete-after           receiver deletes after transfer, not during
           --delete-excluded        also delete excluded files from dest dirs
           --ignore-missing-args    ignore missing source args without error
           --delete-missing-args    delete missing source args from destination
           --ignore-errors          delete even if there are I/O errors
           --force                  force deletion of dirs even if not empty
           --max-delete=NUM         don't delete more than NUM files
           --max-size=SIZE          don't transfer any file larger than SIZE
           --min-size=SIZE          don't transfer any file smaller than SIZE
           --max-alloc=SIZE         change a limit relating to memory alloc
           --partial                keep partially transferred files
           --partial-dir=DIR        put a partially transferred file into DIR
           --delay-updates          put all updated files into place at end
           --prune-empty-dirs, -m   prune empty directory chains from file-list
           --numeric-ids            don't map uid/gid values by user/group name
           --usermap=STRING         custom username mapping
           --groupmap=STRING        custom groupname mapping
           --chown=USER:GROUP       simple username/groupname mapping
           --timeout=SECONDS        set I/O timeout in seconds
           --contimeout=SECONDS     set daemon connection timeout in seconds
           --ignore-times, -I       don't skip files that match size and time
           --size-only              skip files that match in size
           --modify-window=NUM, -@  set the accuracy for mod-time comparisons
           --temp-dir=DIR, -T       create temporary files in directory DIR
           --fuzzy, -y              find similar file for basis if no dest file
           --compare-dest=DIR       also compare destination files relative to DIR
           --copy-dest=DIR          ... and include copies of unchanged files
           --link-dest=DIR          hardlink to files in DIR when unchanged
           --compress, -z           compress file data during the transfer
           --compress-choice=STR    choose the compression algorithm (aka --zc)
           --compress-level=NUM     explicitly set compression level (aka --zl)
           --skip-compress=LIST     skip compressing files with suffix in LIST
           --cvs-exclude, -C        auto-ignore files in the same way CVS does
           --filter=RULE, -f        add a file-filtering RULE
           -F                       same as --filter='dir-merge /.rsync-filter'
                                    repeated: --filter='- .rsync-filter'
           --exclude=PATTERN        exclude files matching PATTERN
           --exclude-from=FILE      read exclude patterns from FILE
           --include=PATTERN        don't exclude files matching PATTERN
           --include-from=FILE      read include patterns from FILE
           --files-from=FILE        read list of source-file names from FILE
           --from0, -0              all *-from/filter files are delimited by 0s
           --old-args               disable the modern arg-protection idiom
           --secluded-args, -s      use the protocol to safely send the args
           --trust-sender           trust the remote sender's file list
           --copy-as=USER[:GROUP]   specify user & optional group for the copy
           --address=ADDRESS        bind address for outgoing socket to daemon
           --port=PORT              specify double-colon alternate port number
           --sockopts=OPTIONS       specify custom TCP options
           --blocking-io            use blocking I/O for the remote shell
           --outbuf=N|L|B           set out buffering to None, Line, or Block
           --stats                  give some file-transfer stats
           --8-bit-output, -8       leave high-bit chars unescaped in output
           --human-readable, -h     output numbers in a human-readable format
           --progress               show progress during transfer
           -P                       same as --partial --progress
           --itemize-changes, -i    output a change-summary for all updates
           --remote-option=OPT, -M  send OPTION to the remote side only
           --out-format=FORMAT      output updates using the specified FORMAT
           --log-file=FILE          log what we're doing to the specified FILE
           --log-file-format=FMT    log updates using the specified FMT
           --password-file=FILE     read daemon-access password from FILE
           --early-input=FILE       use FILE for daemon's early exec input
           --list-only              list the files instead of copying them
           --bwlimit=RATE           limit socket I/O bandwidth
           --stop-after=MINS        Stop rsync after MINS minutes have elapsed
           --stop-at=y-m-dTh:m      Stop rsync at the specified point in time
           --fsync                  fsync every written file
           --write-batch=FILE       write a batched update to FILE
           --only-write-batch=FILE  like --write-batch but w/o updating dest
           --read-batch=FILE        read a batched update from FILE
           --protocol=NUM           force an older protocol version to be used
           --iconv=CONVERT_SPEC     request charset conversion of filenames
           --checksum-seed=NUM      set block/file checksum seed (advanced)
           --ipv4, -4               prefer IPv4
           --ipv6, -6               prefer IPv6
           --version, -V            print the version + other info and exit
           --help, -h (*)           show this help (* -h is help only on its own)
    
           Rsync can also be run as a daemon, in which case the following
           options are accepted:
    
           --daemon                 run as an rsync daemon
           --address=ADDRESS        bind to the specified address
           --bwlimit=RATE           limit socket I/O bandwidth
           --config=FILE            specify alternate rsyncd.conf file
           --dparam=OVERRIDE, -M    override global daemon config parameter
           --no-detach              do not detach from the parent
           --port=PORT              listen on alternate port number
           --log-file=FILE          override the "log file" setting
           --log-file-format=FMT    override the "log format" setting
           --sockopts=OPTIONS       specify custom TCP options
           --verbose, -v            increase verbosity
           --ipv4, -4               prefer IPv4
           --ipv6, -6               prefer IPv6
           --help, -h               show this help (when used with --daemon)
    


## OPTIONS



           Rsync accepts both long (double-dash + word) and short (single-
           dash + letter) options.  The full list of the available options
           are described below.  If an option can be specified in more than
           one way, the choices are comma-separated.  Some options only have
           a long variant, not a short.
    
           If the option takes a parameter, the parameter is only listed
           after the long variant, even though it must also be specified for
           the short.  When specifying a parameter, you can either use the
           form **--option=param** , **--option param** , **-o=param** , **-o param** , or
           **-oparam**(the latter choices assume that your option has a short
           variant).
    
           The parameter may need to be quoted in some manner for it to
           survive the shell's command-line parsing.  Also keep in mind that
           a leading tilde (**~**) in a pathname is substituted by your shell, so
           make sure that you separate the option name from the pathname
           using a space if you want the local shell to expand it.
    
           **--help** Print a short help page describing the options available in
                  rsync and exit.  You can also use **-h** for **--help** when it is
                  used without any other options (since it normally means
                  **--human-readable**).
    
           **--version** , **-V**
                  Print the rsync version plus other info and exit.  When
                  repeated, the information is output is a JSON format that
                  is still fairly readable (client side only).
    
                  The output includes a list of compiled-in capabilities, a
                  list of optimizations, the default list of checksum
                  algorithms, the default list of compression algorithms, the
                  default list of daemon auth digests, a link to the rsync
                  web site, and a few other items.
    
           **--verbose** , **-v**
                  This option increases the amount of information you are
                  given during the transfer.  By default, rsync works
                  silently.  A single **-v** will give you information about what
                  files are being transferred and a brief summary at the end.
                  Two **-v** options will give you information on what files are
                  being skipped and slightly more information at the end.
                  More than two **-v** options should only be used if you are
                  debugging rsync.
    
                  The end-of-run summary tells you the number of bytes sent
                  to the remote rsync (which is the receiving side on a local
                  copy), the number of bytes received from the remote host,
                  and the average bytes per second of the transferred data
                  computed over the entire length of the rsync run. The
                  second line shows the total size (in bytes), which is the
                  sum of all the file sizes that rsync considered
                  transferring.  It also shows a "speedup" value, which is a
                  ratio of the total file size divided by the sum of the sent
                  and received bytes (which is really just a feel-good
                  bigger-is-better number).  Note that these byte values can
                  be made more (or less) human-readable by using the **--human-**
                  **readable**(or **--no-human-readable**) options.
    
                  In a modern rsync, the **-v** option is equivalent to the
                  setting of groups of **--info** and **--debug** options.  You can
                  choose to use these newer options in addition to, or in
                  place of using **--verbose** , as any fine-grained settings
                  override the implied settings of **-v**.  Both **--info** and
                  **--debug** have a way to ask for help that tells you exactly
                  what flags are set for each increase in verbosity.
    
                  However, do keep in mind that a daemon's "**max verbosity** "
                  setting will limit how high of a level the various
                  individual flags can be set on the daemon side.  For
                  instance, if the max is 2, then any info and/or debug flag
                  that is set to a higher value than what would be set by **-vv**
                  will be downgraded to the **-vv** level in the daemon's
                  logging.
    
           **--info=FLAGS**
                  This option lets you have fine-grained control over the
                  information output you want to see.  An individual flag
                  name may be followed by a level number, with 0 meaning to
                  silence that output, 1 being the default output level, and
                  higher numbers increasing the output of that flag (for
                  those that support higher levels).  Use **--info=help** to see
                  all the available flag names, what they output, and what
                  flag names are added for each increase in the verbose
                  level.  Some examples:
    
                      rsync -a --info=progress2 src/ dest/
                      rsync -avv --info=stats2,misc1,flist0 src/ dest/
    
                  Note that **--info=name** 's output is affected by the **--out-**
                  **format** and **--itemize-changes**(**-i**) options.  See those
                  options for more information on what is output and when.
    
                  This option was added to 3.1.0, so an older rsync on the
                  server side might reject your attempts at fine-grained
                  control (if one or more flags needed to be send to the
                  server and the server was too old to understand them).  See
                  also the "**max verbosity** " caveat above when dealing with a
                  daemon.
    
           **--debug=FLAGS**
                  This option lets you have fine-grained control over the
                  debug output you want to see.  An individual flag name may
                  be followed by a level number, with 0 meaning to silence
                  that output, 1 being the default output level, and higher
                  numbers increasing the output of that flag (for those that
                  support higher levels).  Use **--debug=help** to see all the
                  available flag names, what they output, and what flag names
                  are added for each increase in the verbose level.  Some
                  examples:
    
                      rsync -avvv --debug=none src/ dest/
                      rsync -avA --del --debug=del2,acl src/ dest/
    
                  Note that some debug messages will only be output when the
                  **--stderr=all** option is specified, especially those
                  pertaining to I/O and buffer debugging.
    
                  Beginning in 3.2.0, this option is no longer auto-forwarded
                  to the server side in order to allow you to specify
                  different debug values for each side of the transfer, as
                  well as to specify a new debug option that is only present
                  in one of the rsync versions.  If you want to duplicate the
                  same option on both sides, using brace expansion is an easy
                  way to save you some typing.  This works in zsh and bash:
    
                      rsync -aiv {-M,}--debug=del2 src/ dest/
    
           **--stderr=errors|all|client**
                  This option controls which processes output to stderr and
                  if info messages are also changed to stderr.  The mode
                  strings can be abbreviated, so feel free to use a single
                  letter value.  The 3 possible choices are:
    
                  o      **errors** - (the default) causes all the rsync
                         processes to send an error directly to stderr, even
                         if the process is on the remote side of the
                         transfer.  Info messages are sent to the client side
                         via the protocol stream.  If stderr is not available
                         (i.e. when directly connecting with a daemon via a
                         socket) errors fall back to being sent via the
                         protocol stream.
    
                  o      **all** - causes all rsync messages (info and error) to
                         get written directly to stderr from all (possible)
                         processes.  This causes stderr to become line-
                         buffered (instead of raw) and eliminates the ability
                         to divide up the info and error messages by file
                         handle.  For those doing debugging or using several
                         levels of verbosity, this option can help to avoid
                         clogging up the transfer stream (which should
                         prevent any chance of a deadlock bug hanging things
                         up).  It also allows **--debug** to enable some extra
                         I/O related messages.
    
                  o      **client** - causes all rsync messages to be sent to the
                         client side via the protocol stream.  One client
                         process outputs all messages, with errors on stderr
                         and info messages on stdout.  This **was** the default
                         in older rsync versions, but can cause error delays
                         when a lot of transfer data is ahead of the
                         messages.  If you're pushing files to an older
                         rsync, you may want to use **--stderr=all** since that
                         idiom has been around for several releases.
    
                  This option was added in rsync 3.2.3.  This version also
                  began the forwarding of a non-default setting to the remote
                  side, though rsync uses the backward-compatible options
                  **--msgs2stderr** and **--no-msgs2stderr** to represent the **all** and
                  **client** settings, respectively.  A newer rsync will continue
                  to accept these older option names to maintain
                  compatibility.
    
           **--quiet** , **-q**
                  This option decreases the amount of information you are
                  given during the transfer, notably suppressing information
                  messages from the remote server.  This option is useful
                  when invoking rsync from cron.
    
           **--no-motd**
                  This option affects the information that is output by the
                  client at the start of a daemon transfer.  This suppresses
                  the message-of-the-day (MOTD) text, but it also affects the
                  list of modules that the daemon sends in response to the
                  "rsync host::" request (due to a limitation in the rsync
                  protocol), so omit this option if you want to request the
                  list of modules from the daemon.
    
           **--ignore-times** , **-I**
                  Normally rsync will skip any files that are already the
                  same size and have the same modification timestamp.  This
                  option turns off this "quick check" behavior, causing all
                  files to be updated.
    
                  This option can be confusing compared to **--ignore-existing**
                  and **--ignore-non-existing** in that that they cause rsync to
                  transfer fewer files, while this option causes rsync to
                  transfer more files.
    
           **--size-only**
                  This modifies rsync's "quick check" algorithm for finding
                  files that need to be transferred, changing it from the
                  default of transferring files with either a changed size or
                  a changed last-modified time to just looking for files that
                  have changed in size.  This is useful when starting to use
                  rsync after using another mirroring system which may not
                  preserve timestamps exactly.
    
           **--modify-window=NUM** , **-@**
                  When comparing two timestamps, rsync treats the timestamps
                  as being equal if they differ by no more than the modify-
                  window value.  The default is 0, which matches just integer
                  seconds.  If you specify a negative value (and the receiver
                  is at least version 3.1.3) then nanoseconds will also be
                  taken into account.  Specifying 1 is useful for copies
                  to/from MS Windows FAT filesystems, because FAT represents
                  times with a 2-second resolution (allowing times to differ
                  from the original by up to 1 second).
    
                  If you want all your transfers to default to comparing
                  nanoseconds, you can create a **~/.popt** file and put these
                  lines in it:
    
                      rsync alias -a -a@-1
                      rsync alias -t -t@-1
    
                  With that as the default, you'd need to specify **--modify-**
                  **window=0**(aka **-@0**) to override it and ignore nanoseconds,
                  e.g. if you're copying between ext3 and ext4, or if the
                  receiving rsync is older than 3.1.3.
    
           **--checksum** , **-c**
                  This changes the way rsync checks if the files have been
                  changed and are in need of a transfer.  Without this
                  option, rsync uses a "quick check" that (by default) checks
                  if each file's size and time of last modification match
                  between the sender and receiver.  This option changes this
                  to compare a 128-bit checksum for each file that has a
                  matching size.  Generating the checksums means that both
                  sides will expend a lot of disk I/O reading all the data in
                  the files in the transfer, so this can slow things down
                  significantly (and this is prior to any reading that will
                  be done to transfer changed files)
    
                  The sending side generates its checksums while it is doing
                  the file-system scan that builds the list of the available
                  files.  The receiver generates its checksums when it is
                  scanning for changed files, and will checksum any file that
                  has the same size as the corresponding sender's file: files
                  with either a changed size or a changed checksum are
                  selected for transfer.
    
                  Note that rsync always verifies that each _transferred_ file
                  was correctly reconstructed on the receiving side by
                  checking a whole-file checksum that is generated as the
                  file is transferred, but that automatic after-the-transfer
                  verification has nothing to do with this option's before-
                  the-transfer "Does this file need to be updated?" check.
    
                  The checksum used is auto-negotiated between the client and
                  the server, but can be overridden using either the
                  **--checksum-choice**(**--cc**) option or an environment variable
                  that is discussed in that option's section.
    
           **--archive** , **-a**
                  This is equivalent to **-rlptgoD**.  It is a quick way of
                  saying you want recursion and want to preserve almost
                  everything.  Be aware that it does **not** include preserving
                  ACLs (**-A**), xattrs (**-X**), atimes (**-U**), crtimes (**-N**), nor the
                  finding and preserving of hardlinks (**-H**).
    
                  The only exception to the above equivalence is when
                  **--files-from** is specified, in which case **-r** is not implied.
    
           **--no-OPTION**
                  You may turn off one or more implied options by prefixing
                  the option name with "no-".  Not all positive options have
                  a negated opposite, but a lot do, including those that can
                  be used to disable an implied option (e.g.  **--no-D** , **--no-**
                  **perms**) or have different defaults in various circumstances
                  (e.g. **--no-whole-file** , **--no-blocking-io** , **--no-dirs**).  Every
                  valid negated option accepts both the short and the long
                  option name after the "no-" prefix (e.g. **--no-R** is the same
                  as **--no-relative**).
    
                  As an example, if you want to use **--archive**(**-a**) but don't
                  want **--owner**(**-o**), instead of converting **-a** into **-rlptgD** ,
                  you can specify **-a --no-o**(aka **--archive --no-owner**).
    
                  The order of the options is important: if you specify **--no-**
                  **r -a** , the **-r** option would end up being turned on, the
                  opposite of **-a --no-r**.  Note also that the side-effects of
                  the **--files-from** option are NOT positional, as it affects
                  the default state of several options and slightly changes
                  the meaning of **-a**(see the **--files-from** option for more
                  details).
    
           **--recursive** , **-r**
                  This tells rsync to copy directories recursively.  See also
                  **--dirs**(**-d**) for an option that allows the scanning of a
                  single directory.
    
                  See the **--inc-recursive** option for a discussion of the
                  incremental recursion for creating the list of files to
                  transfer.
    
           **--inc-recursive** , **--i-r**
                  This option explicitly enables on incremental recursion
                  when scanning for files, which is enabled by default when
                  using the **--recursive** option and both sides of the transfer
                  are running rsync 3.0.0 or newer.
    
                  Incremental recursion uses much less memory than non-
                  incremental, while also beginning the transfer more quickly
                  (since it doesn't need to scan the entire transfer
                  hierarchy before it starts transferring files).  If no
                  recursion is enabled in the source files, this option has
                  no effect.
    
                  Some options require rsync to know the full file list, so
                  these options disable the incremental recursion mode.
                  These include:
    
                  o      **--delete-before**(the old default of **--delete**)
    
                  o      **--delete-after**
    
                  o      **--prune-empty-dirs**
    
                  o      **--delay-updates**
    
                  In order to make **--delete** compatible with incremental
                  recursion, rsync 3.0.0 made **--delete-during** the default
                  delete mode (which was first added in 2.6.4).
    
                  One side-effect of incremental recursion is that any
                  missing sub-directories inside a recursively-scanned
                  directory are (by default) created prior to recursing into
                  the sub-dirs.  This earlier creation point (compared to a
                  non-incremental recursion) allows rsync to then set the
                  modify time of the finished directory right away (without
                  having to delay that until a bunch of recursive copying has
                  finished).  However, these early directories don't yet have
                  their completed mode, mtime, or ownership set -- they have
                  more restrictive rights until the subdirectory's copying
                  actually begins.  This early-creation idiom can be avoided
                  by using the **--omit-dir-times** option.
    
                  Incremental recursion can be disabled using the **--no-inc-**
                  **recursive**(**--no-i-r**) option.
    
           **--no-inc-recursive** , **--no-i-r**
                  Disables the new incremental recursion algorithm of the
                  **--recursive** option.  This makes rsync scan the full file
                  list before it begins to transfer files.  See **--inc-**
                  **recursive** for more info.
    
           **--relative** , **-R**
                  Use relative paths.  This means that the full path names
                  specified on the command line are sent to the server rather
                  than just the last parts of the filenames.  This is
                  particularly useful when you want to send several different
                  directories at the same time.  For example, if you used
                  this command:
    
                      rsync -av /foo/bar/baz.c remote:/tmp/
    
                  would create a file named baz.c in /tmp/ on the remote
                  machine.  If instead you used
    
                      rsync -avR /foo/bar/baz.c remote:/tmp/
    
                  then a file named /tmp/foo/bar/baz.c would be created on
                  the remote machine, preserving its full path.  These extra
                  path elements are called "implied directories" (i.e. the
                  "foo" and the "foo/bar" directories in the above example).
    
                  Beginning with rsync 3.0.0, rsync always sends these
                  implied directories as real directories in the file list,
                  even if a path element is really a symlink on the sending
                  side.  This prevents some really unexpected behaviors when
                  copying the full path of a file that you didn't realize had
                  a symlink in its path.  If you want to duplicate a server-
                  side symlink, include both the symlink via its path, and
                  referent directory via its real path.  If you're dealing
                  with an older rsync on the sending side, you may need to
                  use the **--no-implied-dirs** option.
    
                  It is also possible to limit the amount of path information
                  that is sent as implied directories for each path you
                  specify.  With a modern rsync on the sending side
                  (beginning with 2.6.7), you can insert a dot and a slash
                  into the source path, like this:
    
                      rsync -avR /foo/./bar/baz.c remote:/tmp/
    
                  That would create /tmp/bar/baz.c on the remote machine.
                  (Note that the dot must be followed by a slash, so "/foo/."
                  would not be abbreviated.) For older rsync versions, you
                  would need to use a chdir to limit the source path.  For
                  example, when pushing files:
    
                      (cd /foo; rsync -avR bar/baz.c remote:/tmp/)
    
                  (Note that the parens put the two commands into a sub-
                  shell, so that the "cd" command doesn't remain in effect
                  for future commands.) If you're pulling files from an older
                  rsync, use this idiom (but only for a non-daemon transfer):
    
                      rsync -avR --rsync-path="cd /foo; rsync" \
                           remote:bar/baz.c /tmp/
    
           **--no-implied-dirs**
                  This option affects the default behavior of the **--relative**
                  option.  When it is specified, the attributes of the
                  implied directories from the source names are not included
                  in the transfer.  This means that the corresponding path
                  elements on the destination system are left unchanged if
                  they exist, and any missing implied directories are created
                  with default attributes.  This even allows these implied
                  path elements to have big differences, such as being a
                  symlink to a directory on the receiving side.
    
                  For instance, if a command-line arg or a files-from entry
                  told rsync to transfer the file "path/foo/file", the
                  directories "path" and "path/foo" are implied when
                  **--relative** is used.  If "path/foo" is a symlink to "bar" on
                  the destination system, the receiving rsync would
                  ordinarily delete "path/foo", recreate it as a directory,
                  and receive the file into the new directory.  With **--no-**
                  **implied-dirs** , the receiving rsync updates "path/foo/file"
                  using the existing path elements, which means that the file
                  ends up being created in "path/bar".  Another way to
                  accomplish this link preservation is to use the **--keep-**
                  **dirlinks** option (which will also affect symlinks to
                  directories in the rest of the transfer).
    
                  When pulling files from an rsync older than 3.0.0, you may
                  need to use this option if the sending side has a symlink
                  in the path you request and you wish the implied
                  directories to be transferred as normal directories.
    
           **--backup** , **-b**
                  With this option, preexisting destination files are renamed
                  as each file is transferred or deleted.  You can control
                  where the backup file goes and what (if any) suffix gets
                  appended using the **--backup-dir** and **--suffix** options.
    
                  If you don't specify **--backup-dir** :
    
                  1.     the **--omit-dir-times** option will be forced on
    
                  2.     the use of **--delete**(without **--delete-excluded**),
                         causes rsync to add a "protect" filter-rule for the
                         backup suffix to the end of all your existing
                         filters that looks like this: **-f "P *~"**.  This rule
                         prevents previously backed-up files from being
                         deleted.
    
                  Note that if you are supplying your own filter rules, you
                  may need to manually insert your own exclude/protect rule
                  somewhere higher up in the list so that it has a high
                  enough priority to be effective (e.g. if your rules specify
                  a trailing inclusion/exclusion of ***** , the auto-added rule
                  would never be reached).
    
           **--backup-dir=DIR**
                  This implies the **--backup** option, and tells rsync to store
                  all backups in the specified directory on the receiving
                  side.  This can be used for incremental backups.  You can
                  additionally specify a backup suffix using the **--suffix**
                  option (otherwise the files backed up in the specified
                  directory will keep their original filenames).
    
                  Note that if you specify a relative path, the backup
                  directory will be relative to the destination directory, so
                  you probably want to specify either an absolute path or a
                  path that starts with "../".  If an rsync daemon is the
                  receiver, the backup dir cannot go outside the module's
                  path hierarchy, so take extra care not to delete it or copy
                  into it.
    
           **--suffix=SUFFIX**
                  This option allows you to override the default backup
                  suffix used with the **--backup**(**-b**) option.  The default
                  suffix is a **~** if no **--backup-dir** was specified, otherwise
                  it is an empty string.
    
           **--update** , **-u**
                  This forces rsync to skip any files which exist on the
                  destination and have a modified time that is newer than the
                  source file. (If an existing destination file has a
                  modification time equal to the source file's, it will be
                  updated if the sizes are different.)
    
                  Note that this does not affect the copying of dirs,
                  symlinks, or other special files.  Also, a difference of
                  file format between the sender and receiver is always
                  considered to be important enough for an update, no matter
                  what date is on the objects.  In other words, if the source
                  has a directory where the destination has a file, the
                  transfer would occur regardless of the timestamps.
    
                  This option is a TRANSFER RULE, so don't expect any exclude
                  side effects.
    
                  A caution for those that choose to combine **--inplace** with
                  **--update** : an interrupted transfer will leave behind a
                  partial file on the receiving side that has a very recent
                  modified time, so re-running the transfer will probably **not**
                  continue the interrupted file.  As such, it is usually best
                  to avoid combining this with **--inplace** unless you have
                  implemented manual steps to handle any interrupted in-
                  progress files.
    
           **--inplace**
                  This option changes how rsync transfers a file when its
                  data needs to be updated: instead of the default method of
                  creating a new copy of the file and moving it into place
                  when it is complete, rsync instead writes the updated data
                  directly to the destination file.
    
                  This has several effects:
    
                  o      Hard links are not broken.  This means the new data
                         will be visible through other hard links to the
                         destination file.  Moreover, attempts to copy
                         differing source files onto a multiply-linked
                         destination file will result in a "tug of war" with
                         the destination data changing back and forth.
    
                  o      In-use binaries cannot be updated (either the OS
                         will prevent this from happening, or binaries that
                         attempt to swap-in their data will misbehave or
                         crash).
    
                  o      The file's data will be in an inconsistent state
                         during the transfer and will be left that way if the
                         transfer is interrupted or if an update fails.
    
                  o      A file that rsync cannot write to cannot be updated.
                         While a super user can update any file, a normal
                         user needs to be granted write permission for the
                         open of the file for writing to be successful.
    
                  o      The efficiency of rsync's delta-transfer algorithm
                         may be reduced if some data in the destination file
                         is overwritten before it can be copied to a position
                         later in the file.  This does not apply if you use
                         **--backup** , since rsync is smart enough to use the
                         backup file as the basis file for the transfer.
    
                  WARNING: you should not use this option to update files
                  that are being accessed by others, so be careful when
                  choosing to use this for a copy.
    
                  This option is useful for transferring large files with
                  block-based changes or appended data, and also on systems
                  that are disk bound, not network bound.  It can also help
                  keep a copy-on-write filesystem snapshot from diverging the
                  entire contents of a file that only has minor changes.
    
                  The option implies **--partial**(since an interrupted transfer
                  does not delete the file), but conflicts with **--partial-dir**
                  and **--delay-updates**.  Prior to rsync 2.6.4 **--inplace** was
                  also incompatible with **--compare-dest** and **--link-dest**.
    
           **--append**
                  This special copy mode only works to efficiently update
                  files that are known to be growing larger where any
                  existing content on the receiving side is also known to be
                  the same as the content on the sender.  The use of **--append**
                  **can be dangerous** if you aren't 100% sure that all the files
                  in the transfer are shared, growing files.  You should thus
                  use filter rules to ensure that you weed out any files that
                  do not fit this criteria.
    
                  Rsync updates these growing file in-place without verifying
                  any of the existing content in the file (it only verifies
                  the content that it is appending).  Rsync skips any files
                  that exist on the receiving side that are not shorter than
                  the associated file on the sending side (which means that
                  new files are transferred).  It also skips any files whose
                  size on the sending side gets shorter during the send
                  negotiations (rsync warns about a "diminished" file when
                  this happens).
    
                  This does not interfere with the updating of a file's non-
                  content attributes (e.g.  permissions, ownership, etc.)
                  when the file does not need to be transferred, nor does it
                  affect the updating of any directories or non-regular
                  files.
    
           **--append-verify**
                  This special copy mode works like **--append** except that all
                  the data in the file is included in the checksum
                  verification (making it less efficient but also potentially
                  safer).  This option **can be dangerous** if you aren't 100%
                  sure that all the files in the transfer are shared, growing
                  files.  See the **--append** option for more details.
    
                  Note: prior to rsync 3.0.0, the **--append** option worked like
                  **--append-verify** , so if you are interacting with an older
                  rsync (or the transfer is using a protocol prior to 30),
                  specifying either append option will initiate an **--append-**
                  **verify** transfer.
    
           **--dirs** , **-d**
                  Tell the sending side to include any directories that are
                  encountered.  Unlike **--recursive** , a directory's contents
                  are not copied unless the directory name specified is "."
                  or ends with a trailing slash (e.g.  ".", "dir/.", "dir/",
                  etc.).  Without this option or the **--recursive** option,
                  rsync will skip all directories it encounters (and output a
                  message to that effect for each one).  If you specify both
                  **--dirs** and **--recursive** , **--recursive** takes precedence.
    
                  The **--dirs** option is implied by the **--files-from** option or
                  the **--list-only** option (including an implied **--list-only**
                  usage) if **--recursive** wasn't specified (so that directories
                  are seen in the listing).  Specify **--no-dirs**(or **--no-d**) if
                  you want to turn this off.
    
                  There is also a backward-compatibility helper option,
                  **--old-dirs**(**--old-d**) that tells rsync to use a hack of
                  **-r --exclude='/*/*'** to get an older rsync to list a single
                  directory without recursing.
    
           **--mkpath**
                  Create all missing path components of the destination path.
    
                  By default, rsync allows only the final component of the
                  destination path to not exist, which is an attempt to help
                  you to validate your destination path.  With this option,
                  rsync creates all the missing destination-path components,
                  just as if **mkdir -p $DEST_PATH** had been run on the
                  receiving side.
    
                  When specifying a destination path, including a trailing
                  slash ensures that the whole path is treated as directory
                  names to be created, even when the file list has a single
                  item. See the COPYING TO A DIFFERENT NAME section for full
                  details on how rsync decides if a final destination-path
                  component should be created as a directory or not.
    
                  If you would like the newly-created destination dirs to
                  match the dirs on the sending side, you should be using
                  **--relative**(**-R**) instead of **--mkpath**.  For instance, the
                  following two commands result in the same destination tree,
                  but only the second command ensures that the
                  "some/extra/path" components match the dirs on the sending
                  side:
    
                      rsync -ai --mkpath host:some/extra/path/*.c some/extra/path/
                      rsync -aiR host:some/extra/path/*.c ./
    
           **--links** , **-l**
                  Add symlinks to the transferred files instead of noisily
                  ignoring them with a "non-regular file" warning for each
                  symlink encountered.  You can alternately silence the
                  warning by specifying **--info=nonreg0**.
    
                  The default handling of symlinks is to recreate each
                  symlink's unchanged value on the receiving side.
    
                  See the SYMBOLIC LINKS section for multi-option info.
    
           **--copy-links** , **-L**
                  The sender transforms each symlink encountered in the
                  transfer into the referent item, following the symlink
                  chain to the file or directory that it references.  If a
                  symlink chain is broken, an error is output and the file is
                  dropped from the transfer.
    
                  This option supersedes any other options that affect
                  symlinks in the transfer, since there are no symlinks left
                  in the transfer.
    
                  This option does not change the handling of existing
                  symlinks on the receiving side, unlike versions of rsync
                  prior to 2.6.3 which had the side-effect of telling the
                  receiving side to also follow symlinks.  A modern rsync
                  won't forward this option to a remote receiver (since only
                  the sender needs to know about it), so this caveat should
                  only affect someone using an rsync client older than 2.6.7
                  (which is when **-L** stopped being forwarded to the receiver).
    
                  See the **--keep-dirlinks**(**-K**) if you need a symlink to a
                  directory to be treated as a real directory on the
                  receiving side.
    
                  See the SYMBOLIC LINKS section for multi-option info.
    
           **--copy-unsafe-links**
                  This tells rsync to copy the referent of symbolic links
                  that point outside the copied tree.  Absolute symlinks are
                  also treated like ordinary files, and so are any symlinks
                  in the source path itself when **--relative** is used.
    
                  Note that the cut-off point is the top of the transfer,
                  which is the part of the path that rsync isn't mentioning
                  in the verbose output.  If you copy "/src/subdir" to
                  "/dest/" then the "subdir" directory is a name inside the
                  transfer tree, not the top of the transfer (which is /src)
                  so it is legal for created relative symlinks to refer to
                  other names inside the /src and /dest directories.  If you
                  instead copy "/src/subdir/" (with a trailing slash) to
                  "/dest/subdir" that would not allow symlinks to any files
                  outside of "subdir".
    
                  Note that safe symlinks are only copied if **--links** was also
                  specified or implied. The **--copy-unsafe-links** option has no
                  extra effect when combined with **--copy-links**.
    
                  See the SYMBOLIC LINKS section for multi-option info.
    
           **--safe-links**
                  This tells the receiving rsync to ignore any symbolic links
                  in the transfer which point outside the copied tree.  All
                  absolute symlinks are also ignored.
    
                  Since this ignoring is happening on the receiving side, it
                  will still be effective even when the sending side has
                  munged symlinks (when it is using **--munge-links**). It also
                  affects deletions, since the file being present in the
                  transfer prevents any matching file on the receiver from
                  being deleted when the symlink is deemed to be unsafe and
                  is skipped.
    
                  This option must be combined with **--links**(or **--archive**) to
                  have any symlinks in the transfer to conditionally ignore.
                  Its effect is superseded by **--copy-unsafe-links**.
    
                  Using this option in conjunction with **--relative** may give
                  unexpected results.
    
                  See the SYMBOLIC LINKS section for multi-option info.
    
           **--munge-links**
                  This option affects just one side of the transfer and tells
                  rsync to munge symlink values when it is receiving files or
                  unmunge symlink values when it is sending files.  The
                  munged values make the symlinks unusable on disk but allows
                  the original contents of the symlinks to be recovered.
    
                  The server-side rsync often enables this option without the
                  client's knowledge, such as in an rsync daemon's
                  configuration file or by an option given to the rrsync
                  (restricted rsync) script.  When specified on the client
                  side, specify the option normally if it is the client side
                  that has/needs the munged symlinks, or use **-M--munge-links**
                  to give the option to the server when it has/needs the
                  munged symlinks.  Note that on a local transfer, the client
                  is the sender, so specifying the option directly unmunges
                  symlinks while specifying it as a remote option munges
                  symlinks.
    
                  This option has no effect when sent to a daemon via
                  **--remote-option** because the daemon configures whether it
                  wants munged symlinks via its "**munge symlinks** " parameter.
    
                  The symlink value is munged/unmunged once it is in the
                  transfer, so any option that transforms symlinks into non-
                  symlinks occurs prior to the munging/unmunging **except** for
                  **--safe-links** , which is a choice that the receiver makes, so
                  it bases its decision on the munged/unmunged value.  This
                  does mean that if a receiver has munging enabled, that
                  using **--safe-links** will cause all symlinks to be ignored
                  (since they are all absolute).
    
                  The method that rsync uses to munge the symlinks is to
                  prefix each one's value with the string "/rsyncd-munged/".
                  This prevents the links from being used as long as the
                  directory does not exist.  When this option is enabled,
                  rsync will refuse to run if that path is a directory or a
                  symlink to a directory (though it only checks at startup).
                  See also the "munge-symlinks" python script in the support
                  directory of the source code for a way to munge/unmunge one
                  or more symlinks in-place.
    
           **--copy-dirlinks** , **-k**
                  This option causes the sending side to treat a symlink to a
                  directory as though it were a real directory.  This is
                  useful if you don't want symlinks to non-directories to be
                  affected, as they would be using **--copy-links**.
    
                  Without this option, if the sending side has replaced a
                  directory with a symlink to a directory, the receiving side
                  will delete anything that is in the way of the new symlink,
                  including a directory hierarchy (as long as **--force** or
                  **--delete** is in effect).
    
                  See also **--keep-dirlinks** for an analogous option for the
                  receiving side.
    
                  **--copy-dirlinks** applies to all symlinks to directories in
                  the source.  If you want to follow only a few specified
                  symlinks, a trick you can use is to pass them as additional
                  source args with a trailing slash, using **--relative** to make
                  the paths match up right.  For example:
    
                      rsync -r --relative src/./ src/./follow-me/ dest/
    
                  This works because rsync calls lstat(2) on the source arg
                  as given, and the trailing slash makes lstat(2) follow the
                  symlink, giving rise to a directory in the file-list which
                  overrides the symlink found during the scan of "src/./".
    
                  See the SYMBOLIC LINKS section for multi-option info.
    
           **--keep-dirlinks** , **-K**
                  This option causes the receiving side to treat a symlink to
                  a directory as though it were a real directory, but only if
                  it matches a real directory from the sender.  Without this
                  option, the receiver's symlink would be deleted and
                  replaced with a real directory.
    
                  For example, suppose you transfer a directory "foo" that
                  contains a file "file", but "foo" is a symlink to directory
                  "bar" on the receiver.  Without **--keep-dirlinks** , the
                  receiver deletes symlink "foo", recreates it as a
                  directory, and receives the file into the new directory.
                  With **--keep-dirlinks** , the receiver keeps the symlink and
                  "file" ends up in "bar".
    
                  One note of caution: if you use **--keep-dirlinks** , you must
                  trust all the symlinks in the copy or enable the **--munge-**
                  **links** option on the receiving side!  If it is possible for
                  an untrusted user to create their own symlink to any real
                  directory, the user could then (on a subsequent copy)
                  replace the symlink with a real directory and affect the
                  content of whatever directory the symlink references.  For
                  backup copies, you are better off using something like a
                  bind mount instead of a symlink to modify your receiving
                  hierarchy.
    
                  See also **--copy-dirlinks** for an analogous option for the
                  sending side.
    
                  See the SYMBOLIC LINKS section for multi-option info.
    
           **--hard-links** , **-H**
                  This tells rsync to look for hard-linked files in the
                  source and link together the corresponding files on the
                  destination.  Without this option, hard-linked files in the
                  source are treated as though they were separate files.
    
                  This option does NOT necessarily ensure that the pattern of
                  hard links on the destination exactly matches that on the
                  source.  Cases in which the destination may end up with
                  extra hard links include the following:
    
                  o      If the destination contains extraneous hard-links
                         (more linking than what is present in the source
                         file list), the copying algorithm will not break
                         them explicitly.  However, if one or more of the
                         paths have content differences, the normal file-
                         update process will break those extra links (unless
                         you are using the **--inplace** option).
    
                  o      If you specify a **--link-dest** directory that contains
                         hard links, the linking of the destination files
                         against the **--link-dest** files can cause some paths
                         in the destination to become linked together due to
                         the **--link-dest** associations.
    
                  Note that rsync can only detect hard links between files
                  that are inside the transfer set.  If rsync updates a file
                  that has extra hard-link connections to files outside the
                  transfer, that linkage will be broken.  If you are tempted
                  to use the **--inplace** option to avoid this breakage, be very
                  careful that you know how your files are being updated so
                  that you are certain that no unintended changes happen due
                  to lingering hard links (and see the **--inplace** option for
                  more caveats).
    
                  If incremental recursion is active (see **--inc-recursive**),
                  rsync may transfer a missing hard-linked file before it
                  finds that another link for that contents exists elsewhere
                  in the hierarchy.  This does not affect the accuracy of the
                  transfer (i.e. which files are hard-linked together), just
                  its efficiency (i.e. copying the data for a new, early copy
                  of a hard-linked file that could have been found later in
                  the transfer in another member of the hard-linked set of
                  files).  One way to avoid this inefficiency is to disable
                  incremental recursion using the **--no-inc-recursive** option.
    
           **--perms** , **-p**
                  This option causes the receiving rsync to set the
                  destination permissions to be the same as the source
                  permissions. (See also the **--chmod** option for a way to
                  modify what rsync considers to be the source permissions.)
    
                  When this option is _off_ , permissions are set as follows:
    
                  o      Existing files (including updated files) retain
                         their existing permissions, though the
                         **--executability** option might change just the execute
                         permission for the file.
    
                  o      New files get their "normal" permission bits set to
                         the source file's permissions masked with the
                         receiving directory's default permissions (either
                         the receiving process's umask, or the permissions
                         specified via the destination directory's default
                         ACL), and their special permission bits disabled
                         except in the case where a new directory inherits a
                         setgid bit from its parent directory.
    
                  Thus, when **--perms** and **--executability** are both disabled,
                  rsync's behavior is the same as that of other file-copy
                  utilities, such as cp(1) and tar(1).
    
                  In summary: to give destination files (both old and new)
                  the source permissions, use **--perms**.  To give new files the
                  destination-default permissions (while leaving existing
                  files unchanged), make sure that the **--perms** option is off
                  and use **--chmod=ugo=rwX**(which ensures that all non-masked
                  bits get enabled).  If you'd care to make this latter
                  behavior easier to type, you could define a popt alias for
                  it, such as putting this line in the file **~/.popt**(the
                  following defines the **-Z** option, and includes **--no-g** to use
                  the default group of the destination dir):
    
                      rsync alias -Z --no-p --no-g --chmod=ugo=rwX
    
                  You could then use this new option in a command such as
                  this one:
    
                      rsync -avZ src/ dest/
    
                  (Caveat: make sure that **-a** does not follow **-Z** , or it will
                  re-enable the two **--no-*** options mentioned above.)
    
                  The preservation of the destination's setgid bit on newly-
                  created directories when **--perms** is off was added in rsync
                  2.6.7.  Older rsync versions erroneously preserved the
                  three special permission bits for newly-created files when
                  **--perms** was off, while overriding the destination's setgid
                  bit setting on a newly-created directory.  Default ACL
                  observance was added to the ACL patch for rsync 2.6.7, so
                  older (or non-ACL-enabled) rsyncs use the umask even if
                  default ACLs are present.  (Keep in mind that it is the
                  version of the receiving rsync that affects these
                  behaviors.)
    
           **--executability** , **-E**
                  This option causes rsync to preserve the executability (or
                  non-executability) of regular files when **--perms** is not
                  enabled.  A regular file is considered to be executable if
                  at least one 'x' is turned on in its permissions.  When an
                  existing destination file's executability differs from that
                  of the corresponding source file, rsync modifies the
                  destination file's permissions as follows:
    
                  o      To make a file non-executable, rsync turns off all
                         its 'x' permissions.
    
                  o      To make a file executable, rsync turns on each 'x'
                         permission that has a corresponding 'r' permission
                         enabled.
    
                  If **--perms** is enabled, this option is ignored.
    
           **--acls** , **-A**
                  This option causes rsync to update the destination ACLs to
                  be the same as the source ACLs.  The option also implies
                  **--perms**.
    
                  The source and destination systems must have compatible ACL
                  entries for this option to work properly.  See the **--fake-**
                  **super** option for a way to backup and restore ACLs that are
                  not compatible.
    
           **--xattrs** , **-X**
                  This option causes rsync to update the destination extended
                  attributes to be the same as the source ones.
    
                  For systems that support extended-attribute namespaces, a
                  copy being done by a super-user copies all namespaces
                  except system.*.  A normal user only copies the user.*
                  namespace.  To be able to backup and restore non-user
                  namespaces as a normal user, see the **--fake-super** option.
    
                  The above name filtering can be overridden by using one or
                  more filter options with the **x** modifier.  When you specify
                  an xattr-affecting filter rule, rsync requires that you do
                  your own system/user filtering, as well as any additional
                  filtering for what xattr names are copied and what names
                  are allowed to be deleted.  For example, to skip the system
                  namespace, you could specify:
    
                      --filter='-x system.*'
    
                  To skip all namespaces except the user namespace, you could
                  specify a negated-user match:
    
                      --filter='-x! user.*'
    
                  To prevent any attributes from being deleted, you could
                  specify a receiver-only rule that excludes all names:
    
                      --filter='-xr *'
    
                  Note that the **-X** option does not copy rsync's special xattr
                  values (e.g.  those used by **--fake-super**) unless you repeat
                  the option (e.g. **-XX**).  This "copy all xattrs" mode cannot
                  be used with **--fake-super**.
    
           **--chmod=CHMOD**
                  This option tells rsync to apply one or more comma-
                  separated "chmod" modes to the permission of the files in
                  the transfer.  The resulting value is treated as though it
                  were the permissions that the sending side supplied for the
                  file, which means that this option can seem to have no
                  effect on existing files if **--perms** is not enabled.
    
                  In addition to the normal parsing rules specified in the
                  chmod(1) manpage, you can specify an item that should only
                  apply to a directory by prefixing it with a 'D', or specify
                  an item that should only apply to a file by prefixing it
                  with a 'F'.  For example, the following will ensure that
                  all directories get marked set-gid, that no files are
                  other-writable, that both are user-writable and group-
                  writable, and that both have consistent executability
                  across all bits:
    
                      --chmod=Dg+s,ug+w,Fo-w,+X
    
                  Using octal mode numbers is also allowed:
    
                      --chmod=D2775,F664
    
                  It is also legal to specify multiple **--chmod** options, as
                  each additional option is just appended to the list of
                  changes to make.
    
                  See the **--perms** and **--executability** options for how the
                  resulting permission value can be applied to the files in
                  the transfer.
    
           **--owner** , **-o**
                  This option causes rsync to set the owner of the
                  destination file to be the same as the source file, but
                  only if the receiving rsync is being run as the super-user
                  (see also the **--super** and **--fake-super** options).  Without
                  this option, the owner of new and/or transferred files are
                  set to the invoking user on the receiving side.
    
                  The preservation of ownership will associate matching names
                  by default, but may fall back to using the ID number in
                  some circumstances (see also the **--numeric-ids** option for a
                  full discussion).
    
           **--group** , **-g**
                  This option causes rsync to set the group of the
                  destination file to be the same as the source file.  If the
                  receiving program is not running as the super-user (or if
                  **--no-super** was specified), only groups that the invoking
                  user on the receiving side is a member of will be
                  preserved.  Without this option, the group is set to the
                  default group of the invoking user on the receiving side.
    
                  The preservation of group information will associate
                  matching names by default, but may fall back to using the
                  ID number in some circumstances (see also the **--numeric-ids**
                  option for a full discussion).
    
           **--devices**
                  This option causes rsync to transfer character and block
                  device files to the remote system to recreate these
                  devices.  If the receiving rsync is not being run as the
                  super-user, rsync silently skips creating the device files
                  (see also the **--super** and **--fake-super** options).
    
                  By default, rsync generates a "non-regular file" warning
                  for each device file encountered when this option is not
                  set.  You can silence the warning by specifying
                  **--info=nonreg0**.
    
           **--specials**
                  This option causes rsync to transfer special files, such as
                  named sockets and fifos.  If the receiving rsync is not
                  being run as the super-user, rsync silently skips creating
                  the special files (see also the **--super** and **--fake-super**
                  options).
    
                  By default, rsync generates a "non-regular file" warning
                  for each special file encountered when this option is not
                  set.  You can silence the warning by specifying
                  **--info=nonreg0**.
    
           **-D** The **-D** option is equivalent to "**--devices --specials** ".
    
           **--copy-devices**
                  This tells rsync to treat a device on the sending side as a
                  regular file, allowing it to be copied to a normal
                  destination file (or another device if **--write-devices** was
                  also specified).
    
                  This option is refused by default by an rsync daemon.
    
           **--write-devices**
                  This tells rsync to treat a device on the receiving side as
                  a regular file, allowing the writing of file data into a
                  device.
    
                  This option implies the **--inplace** option.
    
                  Be careful using this, as you should know what devices are
                  present on the receiving side of the transfer, especially
                  when running rsync as root.
    
                  This option is refused by default by an rsync daemon.
    
           **--times** , **-t**
                  This tells rsync to transfer modification times along with
                  the files and update them on the remote system.  Note that
                  if this option is not used, the optimization that excludes
                  files that have not been modified cannot be effective; in
                  other words, a missing **-t**(or **-a**) will cause the next
                  transfer to behave as if it used **--ignore-times**(**-I**),
                  causing all files to be updated (though rsync's delta-
                  transfer algorithm will make the update fairly efficient if
                  the files haven't actually changed, you're much better off
                  using **-t**).
    
                  A modern rsync that is using transfer protocol 30 or 31
                  conveys a modify time using up to 8-bytes. If rsync is
                  forced to speak an older protocol (perhaps due to the
                  remote rsync being older than 3.0.0) a modify time is
                  conveyed using 4-bytes. Prior to 3.2.7, these shorter
                  values could convey a date range of 13-Dec-1901 to
                  19-Jan-2038.  Beginning with 3.2.7, these 4-byte values now
                  convey a date range of 1-Jan-1970 to 7-Feb-2106.  If you
                  have files dated older than 1970, make sure your rsync
                  executables are upgraded so that the full range of dates
                  can be conveyed.
    
           **--atimes** , **-U**
                  This tells rsync to set the access (use) times of the
                  destination files to the same value as the source files.
    
                  If repeated, it also sets the **--open-noatime** option, which
                  can help you to make the sending and receiving systems have
                  the same access times on the transferred files without
                  needing to run rsync an extra time after a file is
                  transferred.
    
                  Note that some older rsync versions (prior to 3.2.0) may
                  have been built with a pre-release **--atimes** patch that does
                  not imply **--open-noatime** when this option is repeated.
    
           **--open-noatime**
                  This tells rsync to open files with the O_NOATIME flag (on
                  systems that support it) to avoid changing the access time
                  of the files that are being transferred.  If your OS does
                  not support the O_NOATIME flag then rsync will silently
                  ignore this option.  Note also that some filesystems are
                  mounted to avoid updating the atime on read access even
                  without the O_NOATIME flag being set.
    
           **--crtimes** , **-N,**
                  This tells rsync to set the create times (newness) of the
                  destination files to the same value as the source files.
                  Your OS & filesystem must support the setting of arbitrary
                  creation (birth) times for this option to be supported.
    
           **--omit-dir-times** , **-O**
                  This tells rsync to omit directories when it is preserving
                  modification, access, and create times.  If NFS is sharing
                  the directories on the receiving side, it is a good idea to
                  use **-O**.  This option is inferred if you use **--backup**
                  without **--backup-dir**.
    
                  This option also has the side-effect of avoiding early
                  creation of missing sub-directories when incremental
                  recursion is enabled, as discussed in the **--inc-recursive**
                  section.
    
           **--omit-link-times** , **-J**
                  This tells rsync to omit symlinks when it is preserving
                  modification, access, and create times.
    
           **--super**
                  This tells the receiving side to attempt super-user
                  activities even if the receiving rsync wasn't run by the
                  super-user.  These activities include: preserving users via
                  the **--owner** option, preserving all groups (not just the
                  current user's groups) via the **--group** option, and copying
                  devices via the **--devices** option.  This is useful for
                  systems that allow such activities without being the super-
                  user, and also for ensuring that you will get errors if the
                  receiving side isn't being run as the super-user.  To turn
                  off super-user activities, the super-user can use **--no-**
                  **super**.
    
           **--fake-super**
                  When this option is enabled, rsync simulates super-user
                  activities by saving/restoring the privileged attributes
                  via special extended attributes that are attached to each
                  file (as needed).  This includes the file's owner and group
                  (if it is not the default), the file's device info (device
                  & special files are created as empty text files), and any
                  permission bits that we won't allow to be set on the real
                  file (e.g. the real file gets u-s,g-s,o-t for safety) or
                  that would limit the owner's access (since the real super-
                  user can always access/change a file, the files we create
                  can always be accessed/changed by the creating user).  This
                  option also handles ACLs (if **--acls** was specified) and non-
                  user extended attributes (if **--xattrs** was specified).
    
                  This is a good way to backup data without using a super-
                  user, and to store ACLs from incompatible systems.
    
                  The **--fake-super** option only affects the side where the
                  option is used.  To affect the remote side of a remote-
                  shell connection, use the **--remote-option**(**-M**) option:
    
                      rsync -av -M--fake-super /src/ host:/dest/
    
                  For a local copy, this option affects both the source and
                  the destination.  If you wish a local copy to enable this
                  option just for the destination files, specify **-M--fake-**
                  **super**.  If you wish a local copy to enable this option just
                  for the source files, combine **--fake-super** with **-M--super**.
    
                  This option is overridden by both **--super** and **--no-super**.
    
                  See also the **fake super** setting in the daemon's rsyncd.conf
                  file.
    
           **--sparse** , **-S**
                  Try to handle sparse files efficiently so they take up less
                  space on the destination.  If combined with **--inplace** the
                  file created might not end up with sparse blocks with some
                  combinations of kernel version and/or filesystem type.  If
                  **--whole-file** is in effect (e.g. for a local copy) then it
                  will always work because rsync truncates the file prior to
                  writing out the updated version.
    
                  Note that versions of rsync older than 3.1.3 will reject
                  the combination of **--sparse** and **--inplace**.
    
           **--preallocate**
                  This tells the receiver to allocate each destination file
                  to its eventual size before writing data to the file.
                  Rsync will only use the real filesystem-level preallocation
                  support provided by Linux's fallocate(2) system call or
                  Cygwin's posix_fallocate(3), not the slow glibc
                  implementation that writes a null byte into each block.
    
                  Without this option, larger files may not be entirely
                  contiguous on the filesystem, but with this option rsync
                  will probably copy more slowly.  If the destination is not
                  an extent-supporting filesystem (such as ext4, xfs, NTFS,
                  etc.), this option may have no positive effect at all.
    
                  If combined with **--sparse** , the file will only have sparse
                  blocks (as opposed to allocated sequences of null bytes) if
                  the kernel version and filesystem type support creating
                  holes in the allocated data.
    
           **--dry-run** , **-n**
                  This makes rsync perform a trial run that doesn't make any
                  changes (and produces mostly the same output as a real
                  run).  It is most commonly used in combination with the
                  **--verbose**(**-v**) and/or **--itemize-changes**(**-i**) options to see
                  what an rsync command is going to do before one actually
                  runs it.
    
                  The output of **--itemize-changes** is supposed to be exactly
                  the same on a dry run and a subsequent real run (barring
                  intentional trickery and system call failures); if it
                  isn't, that's a bug.  Other output should be mostly
                  unchanged, but may differ in some areas.  Notably, a dry
                  run does not send the actual data for file transfers, so
                  **--progress** has no effect, the "bytes sent", "bytes
                  received", "literal data", and "matched data" statistics
                  are too small, and the "speedup" value is equivalent to a
                  run where no file transfers were needed.
    
           **--whole-file** , **-W**
                  This option disables rsync's delta-transfer algorithm,
                  which causes all transferred files to be sent whole.  The
                  transfer may be faster if this option is used when the
                  bandwidth between the source and destination machines is
                  higher than the bandwidth to disk (especially when the
                  "disk" is actually a networked filesystem).  This is the
                  default when both the source and destination are specified
                  as local paths, but only if no batch-writing option is in
                  effect.
    
           **--no-whole-file** , **--no-W**
                  Disable whole-file updating when it is enabled by default
                  for a local transfer.  This usually slows rsync down, but
                  it can be useful if you are trying to minimize the writes
                  to the destination file (if combined with **--inplace**) or for
                  testing the checksum-based update algorithm.
    
                  See also the **--whole-file** option.
    
           **--checksum-choice=STR** , **--cc=STR**
                  This option overrides the checksum algorithms.  If one
                  algorithm name is specified, it is used for both the
                  transfer checksums and (assuming **--checksum** is specified)
                  the pre-transfer checksums.  If two comma-separated names
                  are supplied, the first name affects the transfer
                  checksums, and the second name affects the pre-transfer
                  checksums (**-c**).
    
                  The checksum options that you may be able to use are:
    
                  o      **auto**(the default automatic choice)
    
                  o      **xxh128**
    
                  o      **xxh3**
    
                  o      **xxh64**(aka **xxhash**)
    
                  o      **md5**
    
                  o      **md4**
    
                  o      **sha1**
    
                  o      **none**
    
                  Run **rsync --version** to see the default checksum list
                  compiled into your version (which may differ from the list
                  above).
    
                  If "none" is specified for the first (or only) name, the
                  **--whole-file** option is forced on and no checksum
                  verification is performed on the transferred data.  If
                  "none" is specified for the second (or only) name, the
                  **--checksum** option cannot be used.
    
                  The "auto" option is the default, where rsync bases its
                  algorithm choice on a negotiation between the client and
                  the server as follows:
    
                  When both sides of the transfer are at least 3.2.0, rsync
                  chooses the first algorithm in the client's list of choices
                  that is also in the server's list of choices.  If no common
                  checksum choice is found, rsync exits with an error.  If
                  the remote rsync is too old to support checksum
                  negotiation, a value is chosen based on the protocol
                  version (which chooses between MD5 and various flavors of
                  MD4 based on protocol age).
    
                  The default order can be customized by setting the
                  environment variable **RSYNC_CHECKSUM_LIST** to a space-
                  separated list of acceptable checksum names.  If the string
                  contains a "**&** " character, it is separated into the "client
                  string & server string", otherwise the same string applies
                  to both.  If the string (or string portion) contains no
                  non-whitespace characters, the default checksum list is
                  used.  This method does not allow you to specify the
                  transfer checksum separately from the pre-transfer
                  checksum, and it discards "auto" and all unknown checksum
                  names.  A list with only invalid names results in a failed
                  negotiation.
    
                  The use of the **--checksum-choice** option overrides this
                  environment list.
    
           **--one-file-system** , **-x**
                  This tells rsync to avoid crossing a filesystem boundary
                  when recursing.  This does not limit the user's ability to
                  specify items to copy from multiple filesystems, just
                  rsync's recursion through the hierarchy of each directory
                  that the user specified, and also the analogous recursion
                  on the receiving side during deletion.  Also keep in mind
                  that rsync treats a "bind" mount to the same device as
                  being on the same filesystem.
    
                  If this option is repeated, rsync omits all mount-point
                  directories from the copy.  Otherwise, it includes an empty
                  directory at each mount-point it encounters (using the
                  attributes of the mounted directory because those of the
                  underlying mount-point directory are inaccessible).
    
                  If rsync has been told to collapse symlinks (via **--copy-**
                  **links** or **--copy-unsafe-links**), a symlink to a directory on
                  another device is treated like a mount-point.  Symlinks to
                  non-directories are unaffected by this option.
    
           **--ignore-non-existing** , **--existing**
                  This tells rsync to skip creating files (including
                  directories) that do not exist yet on the destination.  If
                  this option is combined with the **--ignore-existing** option,
                  no files will be updated (which can be useful if all you
                  want to do is delete extraneous files).
    
                  This option is a TRANSFER RULE, so don't expect any exclude
                  side effects.
    
           **--ignore-existing**
                  This tells rsync to skip updating files that already exist
                  on the destination (this does _not_ ignore existing
                  directories, or nothing would get done).  See also
                  **--ignore-non-existing**.
    
                  This option is a TRANSFER RULE, so don't expect any exclude
                  side effects.
    
                  This option can be useful for those doing backups using the
                  **--link-dest** option when they need to continue a backup run
                  that got interrupted.  Since a **--link-dest** run is copied
                  into a new directory hierarchy (when it is used properly),
                  using [**--ignore-existing** will ensure that the already-
                  handled files don't get tweaked (which avoids a change in
                  permissions on the hard-linked files).  This does mean that
                  this option is only looking at the existing files in the
                  destination hierarchy itself.
    
                  When **--info=skip2** is used rsync will output "FILENAME
                  exists (INFO)" messages where the INFO indicates one of
                  "type change", "sum change" (requires **-c**), "file change"
                  (based on the quick check), "attr change", or "uptodate".
                  Using **--info=skip1**(which is also implied by 2 **-v** options)
                  outputs the exists message without the INFO suffix.
    
           **--remove-source-files**
                  This tells rsync to remove from the sending side the files
                  (meaning non-directories) that are a part of the transfer
                  and have been successfully duplicated on the receiving
                  side.
    
                  Note that you should only use this option on source files
                  that are quiescent.  If you are using this to move files
                  that show up in a particular directory over to another
                  host, make sure that the finished files get renamed into
                  the source directory, not directly written into it, so that
                  rsync can't possibly transfer a file that is not yet fully
                  written.  If you can't first write the files into a
                  different directory, you should use a naming idiom that
                  lets rsync avoid transferring files that are not yet
                  finished (e.g. name the file "foo.new" when it is written,
                  rename it to "foo" when it is done, and then use the option
                  **--exclude='*.new'** for the rsync transfer).
    
                  Starting with 3.1.0, rsync will skip the sender-side
                  removal (and output an error) if the file's size or modify
                  time has not stayed unchanged.
    
                  Starting with 3.2.6, a local rsync copy will ensure that
                  the sender does not remove a file the receiver just
                  verified, such as when the user accidentally makes the
                  source and destination directory the same path.
    
           **--delete**
                  This tells rsync to delete extraneous files from the
                  receiving side (ones that aren't on the sending side), but
                  only for the directories that are being synchronized.  You
                  must have asked rsync to send the whole directory (e.g.
                  "**dir** " or "**dir/** ") without using a wildcard for the
                  directory's contents (e.g. "**dir/*** ") since the wildcard is
                  expanded by the shell and rsync thus gets a request to
                  transfer individual files, not the files' parent directory.
                  Files that are excluded from the transfer are also excluded
                  from being deleted unless you use the **--delete-excluded**
                  option or mark the rules as only matching on the sending
                  side (see the include/exclude modifiers in the FILTER RULES
                  section).
    
                  Prior to rsync 2.6.7, this option would have no effect
                  unless **--recursive** was enabled.  Beginning with 2.6.7,
                  deletions will also occur when **--dirs**(**-d**) is enabled, but
                  only for directories whose contents are being copied.
    
                  This option can be dangerous if used incorrectly! It is a
                  very good idea to first try a run using the **--dry-run**(**-n**)
                  option to see what files are going to be deleted.
    
                  If the sending side detects any I/O errors, then the
                  deletion of any files at the destination will be
                  automatically disabled.  This is to prevent temporary
                  filesystem failures (such as NFS errors) on the sending
                  side from causing a massive deletion of files on the
                  destination.  You can override this with the **--ignore-**
                  **errors** option.
    
                  The **--delete** option may be combined with one of the
                  --delete-WHEN options without conflict, as well as
                  **--delete-excluded**.  However, if none of the **--delete-WHEN**
                  options are specified, rsync will choose the **--delete-**
                  **during** algorithm when talking to rsync 3.0.0 or newer, or
                  the **--delete-before** algorithm when talking to an older
                  rsync.  See also **--delete-delay** and **--delete-after**.
    
           **--delete-before**
                  Request that the file-deletions on the receiving side be
                  done before the transfer starts.  See **--delete**(which is
                  implied) for more details on file-deletion.
    
                  Deleting before the transfer is helpful if the filesystem
                  is tight for space and removing extraneous files would help
                  to make the transfer possible.  However, it does introduce
                  a delay before the start of the transfer, and this delay
                  might cause the transfer to timeout (if **--timeout** was
                  specified).  It also forces rsync to use the old, non-
                  incremental recursion algorithm that requires rsync to scan
                  all the files in the transfer into memory at once (see
                  **--recursive**).
    
           **--delete-during** , **--del**
                  Request that the file-deletions on the receiving side be
                  done incrementally as the transfer happens.  The per-
                  directory delete scan is done right before each directory
                  is checked for updates, so it behaves like a more efficient
                  **--delete-before** , including doing the deletions prior to any
                  per-directory filter files being updated.  This option was
                  first added in rsync version 2.6.4.  See **--delete**(which is
                  implied) for more details on file-deletion.
    
           **--delete-delay**
                  Request that the file-deletions on the receiving side be
                  computed during the transfer (like **--delete-during**), and
                  then removed after the transfer completes.  This is useful
                  when combined with **--delay-updates** and/or **--fuzzy** , and is
                  more efficient than using **--delete-after**(but can behave
                  differently, since **--delete-after** computes the deletions in
                  a separate pass after all updates are done).  If the number
                  of removed files overflows an internal buffer, a temporary
                  file will be created on the receiving side to hold the
                  names (it is removed while open, so you shouldn't see it
                  during the transfer).  If the creation of the temporary
                  file fails, rsync will try to fall back to using **--delete-**
                  **after**(which it cannot do if **--recursive** is doing an
                  incremental scan).  See **--delete**(which is implied) for
                  more details on file-deletion.
    
           **--delete-after**
                  Request that the file-deletions on the receiving side be
                  done after the transfer has completed.  This is useful if
                  you are sending new per-directory merge files as a part of
                  the transfer and you want their exclusions to take effect
                  for the delete phase of the current transfer.  It also
                  forces rsync to use the old, non-incremental recursion
                  algorithm that requires rsync to scan all the files in the
                  transfer into memory at once (see **--recursive**). See
                  **--delete**(which is implied) for more details on file-
                  deletion.
    
                  See also the **--delete-delay** option that might be a faster
                  choice for those that just want the deletions to occur at
                  the end of the transfer.
    
           **--delete-excluded**
                  This option turns any unqualified exclude/include rules
                  into server-side rules that do not affect the receiver's
                  deletions.
    
                  By default, an exclude or include has both a server-side
                  effect (to "hide" and "show" files when building the
                  server's file list) and a receiver-side effect (to
                  "protect" and "risk" files when deletions are occurring).
                  Any rule that has no modifier to specify what sides it is
                  executed on will be instead treated as if it were a server-
                  side rule only, avoiding any "protect" effects of the
                  rules.
    
                  A rule can still apply to both sides even with this option
                  specified if the rule is given both the sender & receiver
                  modifier letters (e.g., **-f'-sr foo'**).  Receiver-side
                  protect/risk rules can also be explicitly specified to
                  limit the deletions.  This saves you from having to edit a
                  bunch of **-f'- foo'** rules into **-f'-s foo'**(aka **-f'H foo'**)
                  rules (not to mention the corresponding includes).
    
                  See the FILTER RULES section for more information.  See
                  **--delete**(which is implied) for more details on deletion.
    
           **--ignore-missing-args**
                  When rsync is first processing the explicitly requested
                  source files (e.g.  command-line arguments or **--files-from**
                  entries), it is normally an error if the file cannot be
                  found.  This option suppresses that error, and does not try
                  to transfer the file.  This does not affect subsequent
                  vanished-file errors if a file was initially found to be
                  present and later is no longer there.
    
           **--delete-missing-args**
                  This option takes the behavior of the (implied) **--ignore-**
                  **missing-args** option a step farther: each missing arg will
                  become a deletion request of the corresponding destination
                  file on the receiving side (should it exist).  If the
                  destination file is a non-empty directory, it will only be
                  successfully deleted if **--force** or **--delete** are in effect.
                  Other than that, this option is independent of any other
                  type of delete processing.
    
                  The missing source files are represented by special file-
                  list entries which display as a "***missing** " entry in the
                  **--list-only** output.
    
           **--ignore-errors**
                  Tells **--delete** to go ahead and delete files even when there
                  are I/O errors.
    
           **--force**
                  This option tells rsync to delete a non-empty directory
                  when it is to be replaced by a non-directory.  This is only
                  relevant if deletions are not active (see **--delete** for
                  details).
    
                  Note for older rsync versions: **--force** used to still be
                  required when using **--delete-after** , and it used to be non-
                  functional unless the **--recursive** option was also enabled.
    
           **--max-delete=NUM**
                  This tells rsync not to delete more than NUM files or
                  directories.  If that limit is exceeded, all further
                  deletions are skipped through the end of the transfer.  At
                  the end, rsync outputs a warning (including a count of the
                  skipped deletions) and exits with an error code of 25
                  (unless some more important error condition also occurred).
    
                  Beginning with version 3.0.0, you may specify **--max-**
                  **delete=0** to be warned about any extraneous files in the
                  destination without removing any of them.  Older clients
                  interpreted this as "unlimited", so if you don't know what
                  version the client is, you can use the less obvious **--max-**
                  **delete=-1** as a backward-compatible way to specify that no
                  deletions be allowed (though really old versions didn't
                  warn when the limit was exceeded).
    
           **--max-size=SIZE**
                  This tells rsync to avoid transferring any file that is
                  larger than the specified SIZE.  A numeric value can be
                  suffixed with a string to indicate the numeric units or
                  left unqualified to specify bytes.  Feel free to use a
                  fractional value along with the units, such as **--max-**
                  **size=1.5m**.
    
                  This option is a TRANSFER RULE, so don't expect any exclude
                  side effects.
    
                  The first letter of a units string can be **B**(bytes), **K**
                  (kilo), **M**(mega), **G**(giga), **T**(tera), or **P**(peta).  If the
                  string is a single char or has "ib" added to it (e.g. "G"
                  or "GiB") then the units are multiples of 1024.  If you use
                  a two-letter suffix that ends with a "B" (e.g. "kb") then
                  you get units that are multiples of 1000.  The string's
                  letters can be any mix of upper and lower-case that you
                  want to use.
    
                  Finally, if the string ends with either "+1" or "-1", it is
                  offset by one byte in the indicated direction.  The largest
                  possible value is usually **8192P-1**.
    
                  Examples: **--max-size=1.5mb-1** is 1499999 bytes, and **--max-**
                  **size=2g+1** is 2147483649 bytes.
    
                  Note that rsync versions prior to 3.1.0 did not allow
                  **--max-size=0**.
    
           **--min-size=SIZE**
                  This tells rsync to avoid transferring any file that is
                  smaller than the specified SIZE, which can help in not
                  transferring small, junk files.  See the **--max-size** option
                  for a description of SIZE and other info.
    
                  Note that rsync versions prior to 3.1.0 did not allow
                  **--min-size=0**.
    
           **--max-alloc=SIZE**
                  By default rsync limits an individual malloc/realloc to
                  about 1GB in size.  For most people this limit works just
                  fine and prevents a protocol error causing rsync to request
                  massive amounts of memory.  However, if you have many
                  millions of files in a transfer, a large amount of server
                  memory, and you don't want to split up your transfer into
                  multiple parts, you can increase the per-allocation limit
                  to something larger and rsync will consume more memory.
    
                  Keep in mind that this is not a limit on the total size of
                  allocated memory.  It is a sanity-check value for each
                  individual allocation.
    
                  See the **--max-size** option for a description of how SIZE can
                  be specified.  The default suffix if none is given is
                  bytes.
    
                  Beginning in 3.2.7, a value of 0 is an easy way to specify
                  SIZE_MAX (the largest limit possible).
    
                  You can set a default value using the environment variable
                  **RSYNC_MAX_ALLOC** using the same SIZE values as supported by
                  this option.  If the remote rsync doesn't understand the
                  **--max-alloc** option, you can override an environmental value
                  by specifying **--max-alloc=1g** , which will make rsync avoid
                  sending the option to the remote side (because "1G" is the
                  default).
    
           **--block-size=SIZE** , **-B**
                  This forces the block size used in rsync's delta-transfer
                  algorithm to a fixed value.  It is normally selected based
                  on the size of each file being updated.  See the technical
                  report for details.
    
                  Beginning in 3.2.3 the SIZE can be specified with a suffix
                  as detailed in the **--max-size** option.  Older versions only
                  accepted a byte count.
    
           **--rsh=COMMAND** , **-e**
                  This option allows you to choose an alternative remote
                  shell program to use for communication between the local
                  and remote copies of rsync.  Typically, rsync is configured
                  to use ssh by default, but you may prefer to use rsh on a
                  local network.
    
                  If this option is used with **[user@]host::module/path** , then
                  the remote shell _COMMAND_ will be used to run an rsync
                  daemon on the remote host, and all data will be transmitted
                  through that remote shell connection, rather than through a
                  direct socket connection to a running rsync daemon on the
                  remote host.  See the USING RSYNC-DAEMON FEATURES VIA A
                  REMOTE-SHELL CONNECTION section above.
    
                  Beginning with rsync 3.2.0, the **RSYNC_PORT** environment
                  variable will be set when a daemon connection is being made
                  via a remote-shell connection.  It is set to 0 if the
                  default daemon port is being assumed, or it is set to the
                  value of the rsync port that was specified via either the
                  **--port** option or a non-empty port value in an **rsync://** URL.
                  This allows the script to discern if a non-default port is
                  being requested, allowing for things such as an SSL or
                  stunnel helper script to connect to a default or alternate
                  port.
    
                  Command-line arguments are permitted in COMMAND provided
                  that COMMAND is presented to rsync as a single argument.
                  You must use spaces (not tabs or other whitespace) to
                  separate the command and args from each other, and you can
                  use single- and/or double-quotes to preserve spaces in an
                  argument (but not backslashes).  Note that doubling a
                  single-quote inside a single-quoted string gives you a
                  single-quote; likewise for double-quotes (though you need
                  to pay attention to which quotes your shell is parsing and
                  which quotes rsync is parsing).  Some examples:
    
                      -e 'ssh -p 2234'
                      -e 'ssh -o "ProxyCommand nohup ssh firewall nc -w1 %h %p"'
    
                  (Note that ssh users can alternately customize site-
                  specific connect options in their .ssh/config file.)
    
                  You can also choose the remote shell program using the
                  **RSYNC_RSH** environment variable, which accepts the same
                  range of values as **-e**.
    
                  See also the **--blocking-io** option which is affected by this
                  option.
    
           **--rsync-path=PROGRAM**
                  Use this to specify what program is to be run on the remote
                  machine to start-up rsync.  Often used when rsync is not in
                  the default remote-shell's path (e.g. **--rsync-**
                  **path=/usr/local/bin/rsync**).  Note that PROGRAM is run with
                  the help of a shell, so it can be any program, script, or
                  command sequence you'd care to run, so long as it does not
                  corrupt the standard-in & standard-out that rsync is using
                  to communicate.
    
                  One tricky example is to set a different default directory
                  on the remote machine for use with the **--relative** option.
                  For instance:
    
                      rsync -avR --rsync-path="cd /a/b && rsync" host:c/d /e/
    
           **--remote-option=OPTION** , **-M**
                  This option is used for more advanced situations where you
                  want certain effects to be limited to one side of the
                  transfer only.  For instance, if you want to pass **--log-**
                  **file=FILE** and **--fake-super** to the remote system, specify it
                  like this:
    
                      rsync -av -M --log-file=foo -M--fake-super src/ dest/
    
                  If you want to have an option affect only the local side of
                  a transfer when it normally affects both sides, send its
                  negation to the remote side.  Like this:
    
                      rsync -av -x -M--no-x src/ dest/
    
                  Be cautious using this, as it is possible to toggle an
                  option that will cause rsync to have a different idea about
                  what data to expect next over the socket, and that will
                  make it fail in a cryptic fashion.
    
                  Note that you should use a separate **-M** option for each
                  remote option you want to pass.  On older rsync versions,
                  the presence of any spaces in the remote-option arg could
                  cause it to be split into separate remote args, but this
                  requires the use of **--old-args** in a modern rsync.
    
                  When performing a local transfer, the "local" side is the
                  sender and the "remote" side is the receiver.
    
                  Note some versions of the popt option-parsing library have
                  a bug in them that prevents you from using an adjacent arg
                  with an equal in it next to a short option letter (e.g.
                  **-M--log-file=/tmp/foo**).  If this bug affects your version
                  of popt, you can use the version of popt that is included
                  with rsync.
    
           **--cvs-exclude** , **-C**
                  This is a useful shorthand for excluding a broad range of
                  files that you often don't want to transfer between
                  systems.  It uses a similar algorithm to CVS to determine
                  if a file should be ignored.
    
                  The exclude list is initialized to exclude the following
                  items (these initial items are marked as perishable -- see
                  the FILTER RULES section):
    
                      **RCS SCCS CVS CVS.adm RCSLOG cvslog.*  tags TAGS**
                      **.make.state .nse_depinfo *~ #* .#* ,* _$* *$ *.old**
                      ***.bak *.BAK *.orig *.rej .del-* *.a *.olb *.o *.obj**
                      ***.so *.exe *.Z *.elc *.ln core .svn/ .git/ .hg/ .bzr/**
    
                  then, files listed in a $HOME/.cvsignore are added to the
                  list and any files listed in the CVSIGNORE environment
                  variable (all cvsignore names are delimited by whitespace).
    
                  Finally, any file is ignored if it is in the same directory
                  as a .cvsignore file and matches one of the patterns listed
                  therein.  Unlike rsync's filter/exclude files, these
                  patterns are split on whitespace.  See the **cvs**(1) manual
                  for more information.
    
                  If you're combining **-C** with your own **--filter** rules, you
                  should note that these CVS excludes are appended at the end
                  of your own rules, regardless of where the **-C** was placed on
                  the command-line.  This makes them a lower priority than
                  any rules you specified explicitly.  If you want to control
                  where these CVS excludes get inserted into your filter
                  rules, you should omit the **-C** as a command-line option and
                  use a combination of **--filter=:C** and **--filter=-C**(either on
                  your command-line or by putting the ":C" and "-C" rules
                  into a filter file with your other rules).  The first
                  option turns on the per-directory scanning for the
                  .cvsignore file.  The second option does a one-time import
                  of the CVS excludes mentioned above.
    
           **--filter=RULE** , **-f**
                  This option allows you to add rules to selectively exclude
                  certain files from the list of files to be transferred.
                  This is most useful in combination with a recursive
                  transfer.
    
                  You may use as many **--filter** options on the command line as
                  you like to build up the list of files to exclude.  If the
                  filter contains whitespace, be sure to quote it so that the
                  shell gives the rule to rsync as a single argument.  The
                  text below also mentions that you can use an underscore to
                  replace the space that separates a rule from its arg.
    
                  See the FILTER RULES section for detailed information on
                  this option.
    
           **-F** The **-F** option is a shorthand for adding two **--filter** rules
                  to your command.  The first time it is used is a shorthand
                  for this rule:
    
                      --filter='dir-merge /.rsync-filter'
    
                  This tells rsync to look for per-directory .rsync-filter
                  files that have been sprinkled through the hierarchy and
                  use their rules to filter the files in the transfer.  If **-F**
                  is repeated, it is a shorthand for this rule:
    
                      --filter='exclude .rsync-filter'
    
                  This filters out the .rsync-filter files themselves from
                  the transfer.
    
                  See the FILTER RULES section for detailed information on
                  how these options work.
    
           **--exclude=PATTERN**
                  This option is a simplified form of the **--filter** option
                  that specifies an exclude rule and does not allow the full
                  rule-parsing syntax of normal filter rules.  This is
                  equivalent to specifying **-f'- PATTERN'**.
    
                  See the FILTER RULES section for detailed information on
                  this option.
    
           **--exclude-from=FILE**
                  This option is related to the **--exclude** option, but it
                  specifies a FILE that contains exclude patterns (one per
                  line).  Blank lines in the file are ignored, as are whole-
                  line comments that start with '**;** ' or '**#** ' (filename rules
                  that contain those characters are unaffected).
    
                  If a line begins with "**-** " (dash, space) or "**+** " (plus,
                  space), then the type of rule is being explicitly specified
                  as an exclude or an include (respectively).  Any rules
                  without such a prefix are taken to be an exclude.
    
                  If a line consists of just "**!** ", then the current filter
                  rules are cleared before adding any further rules.
    
                  If _FILE_ is '**-** ', the list will be read from standard input.
    
           **--include=PATTERN**
                  This option is a simplified form of the **--filter** option
                  that specifies an include rule and does not allow the full
                  rule-parsing syntax of normal filter rules.  This is
                  equivalent to specifying **-f'+ PATTERN'**.
    
                  See the FILTER RULES section for detailed information on
                  this option.
    
           **--include-from=FILE**
                  This option is related to the **--include** option, but it
                  specifies a FILE that contains include patterns (one per
                  line).  Blank lines in the file are ignored, as are whole-
                  line comments that start with '**;** ' or '**#** ' (filename rules
                  that contain those characters are unaffected).
    
                  If a line begins with "**-** " (dash, space) or "**+** " (plus,
                  space), then the type of rule is being explicitly specified
                  as an exclude or an include (respectively).  Any rules
                  without such a prefix are taken to be an include.
    
                  If a line consists of just "**!** ", then the current filter
                  rules are cleared before adding any further rules.
    
                  If _FILE_ is '**-** ', the list will be read from standard input.
    
           **--files-from=FILE**
                  Using this option allows you to specify the exact list of
                  files to transfer (as read from the specified FILE or '**-** '
                  for standard input).  It also tweaks the default behavior
                  of rsync to make transferring just the specified files and
                  directories easier:
    
                  o      The **--relative**(**-R**) option is implied, which
                         preserves the path information that is specified for
                         each item in the file (use **--no-relative** or **--no-R**
                         if you want to turn that off).
    
                  o      The **--dirs**(**-d**) option is implied, which will create
                         directories specified in the list on the destination
                         rather than noisily skipping them (use **--no-dirs** or
                         **--no-d** if you want to turn that off).
    
                  o      The **--archive**(**-a**) option's behavior does not imply
                         **--recursive**(**-r**), so specify it explicitly, if you
                         want it.
    
                  o      These side-effects change the default state of
                         rsync, so the position of the **--files-from** option on
                         the command-line has no bearing on how other options
                         are parsed (e.g. **-a** works the same before or after
                         **--files-from** , as does **--no-R** and all other options).
    
                  The filenames that are read from the FILE are all relative
                  to the source dir -- any leading slashes are removed and no
                  ".." references are allowed to go higher than the source
                  dir.  For example, take this command:
    
                      rsync -a --files-from=/tmp/foo /usr remote:/backup
    
                  If /tmp/foo contains the string "bin" (or even "/bin"), the
                  /usr/bin directory will be created as /backup/bin on the
                  remote host.  If it contains "bin/" (note the trailing
                  slash), the immediate contents of the directory would also
                  be sent (without needing to be explicitly mentioned in the
                  file -- this began in version 2.6.4).  In both cases, if
                  the **-r** option was enabled, that dir's entire hierarchy
                  would also be transferred (keep in mind that **-r** needs to be
                  specified explicitly with **--files-from** , since it is not
                  implied by **-a**.  Also note that the effect of the (enabled
                  by default) **-r** option is to duplicate only the path info
                  that is read from the file -- it does not force the
                  duplication of the source-spec path (/usr in this case).
    
                  In addition, the **--files-from** file can be read from the
                  remote host instead of the local host if you specify a
                  "host:" in front of the file (the host must match one end
                  of the transfer).  As a short-cut, you can specify just a
                  prefix of ":" to mean "use the remote end of the transfer".
                  For example:
    
                      rsync -a --files-from=:/path/file-list src:/ /tmp/copy
    
                  This would copy all the files specified in the /path/file-
                  list file that was located on the remote "src" host.
    
                  If the **--iconv** and **--secluded-args** options are specified
                  and the **--files-from** filenames are being sent from one host
                  to another, the filenames will be translated from the
                  sending host's charset to the receiving host's charset.
    
                  NOTE: sorting the list of files in the **--files-from** input
                  helps rsync to be more efficient, as it will avoid re-
                  visiting the path elements that are shared between adjacent
                  entries.  If the input is not sorted, some path elements
                  (implied directories) may end up being scanned multiple
                  times, and rsync will eventually unduplicate them after
                  they get turned into file-list elements.
    
           **--from0** , **-0**
                  This tells rsync that the rules/filenames it reads from a
                  file are terminated by a null ('\0') character, not a NL,
                  CR, or CR+LF.  This affects **--exclude-from** , **--include-from** ,
                  **--files-from** , and any merged files specified in a **--filter**
                  rule.  It does not affect **--cvs-exclude**(since all names
                  read from a .cvsignore file are split on whitespace).
    
           **--old-args**
                  This option tells rsync to stop trying to protect the arg
                  values on the remote side from unintended word-splitting or
                  other misinterpretation.  It also allows the client to
                  treat an empty arg as a "." instead of generating an error.
    
                  The default in a modern rsync is for "shell-active"
                  characters (including spaces) to be backslash-escaped in
                  the args that are sent to the remote shell.  The wildcard
                  characters ***** , **?** , **[** , & **]** are not escaped in filename args
                  (allowing them to expand into multiple filenames) while
                  being protected in option args, such as **--usermap**.
    
                  If you have a script that wants to use old-style arg
                  splitting in its filenames, specify this option once.  If
                  the remote shell has a problem with any backslash escapes
                  at all, specify this option twice.
    
                  You may also control this setting via the **RSYNC_OLD_ARGS**
                  environment variable.  If it has the value "1", rsync will
                  default to a single-option setting.  If it has the value
                  "2" (or more), rsync will default to a repeated-option
                  setting.  If it is "0", you'll get the default escaping
                  behavior.  The environment is always overridden by manually
                  specified positive or negative options (the negative is
                  **--no-old-args**).
    
                  Note that this option also disables the extra safety check
                  added in 3.2.5 that ensures that a remote sender isn't
                  including extra top-level items in the file-list that you
                  didn't request.  This side-effect is necessary because we
                  can't know for sure what names to expect when the remote
                  shell is interpreting the args.
    
                  This option conflicts with the **--secluded-args** option.
    
           **--secluded-args** , **-s**
                  This option sends all filenames and most options to the
                  remote rsync via the protocol (not the remote shell command
                  line) which avoids letting the remote shell modify them.
                  Wildcards are expanded on the remote host by rsync instead
                  of a shell.
    
                  This is similar to the default backslash-escaping of args
                  that was added in 3.2.4 (see **--old-args**) in that it
                  prevents things like space splitting and unwanted special-
                  character side-effects. However, it has the drawbacks of
                  being incompatible with older rsync versions (prior to
                  3.0.0) and of being refused by restricted shells that want
                  to be able to inspect all the option values for safety.
    
                  This option is useful for those times that you need the
                  argument's character set to be converted for the remote
                  host, if the remote shell is incompatible with the default
                  backslash-escpaing method, or there is some other reason
                  that you want the majority of the options and arguments to
                  bypass the command-line of the remote shell.
    
                  If you combine this option with **--iconv** , the args related
                  to the remote side will be translated from the local to the
                  remote character-set.  The translation happens before wild-
                  cards are expanded.  See also the **--files-from** option.
    
                  You may also control this setting via the
                  **RSYNC_PROTECT_ARGS** environment variable.  If it has a non-
                  zero value, this setting will be enabled by default,
                  otherwise it will be disabled by default.  Either state is
                  overridden by a manually specified positive or negative
                  version of this option (note that **--no-s** and **--no-secluded-**
                  **args** are the negative versions).  This environment variable
                  is also superseded by a non-zero **RSYNC_OLD_ARGS** export.
    
                  This option conflicts with the **--old-args** option.
    
                  This option used to be called **--protect-args**(before 3.2.6)
                  and that older name can still be used (though specifying it
                  as **-s** is always the easiest and most compatible choice).
    
           **--trust-sender**
                  This option disables two extra validation checks that a
                  local client performs on the file list generated by a
                  remote sender.  This option should only be used if you
                  trust the sender to not put something malicious in the file
                  list (something that could possibly be done via a modified
                  rsync, a modified shell, or some other similar
                  manipulation).
    
                  Normally, the rsync client (as of version 3.2.5) runs two
                  extra validation checks when pulling files from a remote
                  rsync:
    
                  o      It verifies that additional arg items didn't get
                         added at the top of the transfer.
    
                  o      It verifies that none of the items in the file list
                         are names that should have been excluded (if filter
                         rules were specified).
    
                  Note that various options can turn off one or both of these
                  checks if the option interferes with the validation.  For
                  instance:
    
                  o      Using a per-directory filter file reads filter rules
                         that only the server knows about, so the filter
                         checking is disabled.
    
                  o      Using the **--old-args** option allows the sender to
                         manipulate the requested args, so the arg checking
                         is disabled.
    
                  o      Reading the files-from list from the server side
                         means that the client doesn't know the arg list, so
                         the arg checking is disabled.
    
                  o      Using **--read-batch** disables both checks since the
                         batch file's contents will have been verified when
                         it was created.
    
                  This option may help an under-powered client server if the
                  extra pattern matching is slowing things down on a huge
                  transfer.  It can also be used to work around a currently-
                  unknown bug in the verification logic for a transfer from a
                  trusted sender.
    
                  When using this option it is a good idea to specify a
                  dedicated destination directory, as discussed in the MULTI-
                  HOST SECURITY section.
    
           **--copy-as=USER[:GROUP]**
                  This option instructs rsync to use the USER and (if
                  specified after a colon) the GROUP for the copy operations.
                  This only works if the user that is running rsync has the
                  ability to change users.  If the group is not specified
                  then the user's default groups are used.
    
                  This option can help to reduce the risk of an rsync being
                  run as root into or out of a directory that might have live
                  changes happening to it and you want to make sure that
                  root-level read or write actions of system files are not
                  possible.  While you could alternatively run all of rsync
                  as the specified user, sometimes you need the root-level
                  host-access credentials to be used, so this allows rsync to
                  drop root for the copying part of the operation after the
                  remote-shell or daemon connection is established.
    
                  The option only affects one side of the transfer unless the
                  transfer is local, in which case it affects both sides.
                  Use the **--remote-option** to affect the remote side, such as
                  **-M--copy-as=joe**.  For a local transfer, the lsh (or lsh.sh)
                  support file provides a local-shell helper script that can
                  be used to allow a "localhost:" or "lh:" host-spec to be
                  specified without needing to setup any remote shells,
                  allowing you to specify remote options that affect the side
                  of the transfer that is using the host-spec (and using
                  hostname "lh" avoids the overriding of the remote directory
                  to the user's home dir).
    
                  For example, the following rsync writes the local files as
                  user "joe":
    
                      sudo rsync -aiv --copy-as=joe host1:backups/joe/ /home/joe/
    
                  This makes all files owned by user "joe", limits the groups
                  to those that are available to that user, and makes it
                  impossible for the joe user to do a timed exploit of the
                  path to induce a change to a file that the joe user has no
                  permissions to change.
    
                  The following command does a local copy into the "dest/"
                  dir as user "joe" (assuming you've installed support/lsh
                  into a dir on your $PATH):
    
                      sudo rsync -aive lsh -M--copy-as=joe src/ lh:dest/
    
           **--temp-dir=DIR** , **-T**
                  This option instructs rsync to use DIR as a scratch
                  directory when creating temporary copies of the files
                  transferred on the receiving side.  The default behavior is
                  to create each temporary file in the same directory as the
                  associated destination file.  Beginning with rsync 3.1.1,
                  the temp-file names inside the specified DIR will not be
                  prefixed with an extra dot (though they will still have a
                  random suffix added).
    
                  This option is most often used when the receiving disk
                  partition does not have enough free space to hold a copy of
                  the largest file in the transfer.  In this case (i.e. when
                  the scratch directory is on a different disk partition),
                  rsync will not be able to rename each received temporary
                  file over the top of the associated destination file, but
                  instead must copy it into place.  Rsync does this by
                  copying the file over the top of the destination file,
                  which means that the destination file will contain
                  truncated data during this copy.  If this were not done
                  this way (even if the destination file were first removed,
                  the data locally copied to a temporary file in the
                  destination directory, and then renamed into place) it
                  would be possible for the old file to continue taking up
                  disk space (if someone had it open), and thus there might
                  not be enough room to fit the new version on the disk at
                  the same time.
    
                  If you are using this option for reasons other than a
                  shortage of disk space, you may wish to combine it with the
                  **--delay-updates** option, which will ensure that all copied
                  files get put into subdirectories in the destination
                  hierarchy, awaiting the end of the transfer.  If you don't
                  have enough room to duplicate all the arriving files on the
                  destination partition, another way to tell rsync that you
                  aren't overly concerned about disk space is to use the
                  **--partial-dir** option with a relative path; because this
                  tells rsync that it is OK to stash off a copy of a single
                  file in a subdir in the destination hierarchy, rsync will
                  use the partial-dir as a staging area to bring over the
                  copied file, and then rename it into place from there.
                  (Specifying a **--partial-dir** with an absolute path does not
                  have this side-effect.)
    
           **--fuzzy** , **-y**
                  This option tells rsync that it should look for a basis
                  file for any destination file that is missing.  The current
                  algorithm looks in the same directory as the destination
                  file for either a file that has an identical size and
                  modified-time, or a similarly-named file.  If found, rsync
                  uses the fuzzy basis file to try to speed up the transfer.
    
                  If the option is repeated, the fuzzy scan will also be done
                  in any matching alternate destination directories that are
                  specified via **--compare-dest** , **--copy-dest** , or **--link-dest**.
    
                  Note that the use of the **--delete** option might get rid of
                  any potential fuzzy-match files, so either use **--delete-**
                  **after** or specify some filename exclusions if you need to
                  prevent this.
    
           **--compare-dest=DIR**
                  This option instructs rsync to use _DIR_ on the destination
                  machine as an additional hierarchy to compare destination
                  files against doing transfers (if the files are missing in
                  the destination directory).  If a file is found in _DIR_ that
                  is identical to the sender's file, the file will NOT be
                  transferred to the destination directory.  This is useful
                  for creating a sparse backup of just files that have
                  changed from an earlier backup.  This option is typically
                  used to copy into an empty (or newly created) directory.
    
                  Beginning in version 2.6.4, multiple **--compare-dest**
                  directories may be provided, which will cause rsync to
                  search the list in the order specified for an exact match.
                  If a match is found that differs only in attributes, a
                  local copy is made and the attributes updated.  If a match
                  is not found, a basis file from one of the _DIRs_ will be
                  selected to try to speed up the transfer.
    
                  If _DIR_ is a relative path, it is relative to the
                  destination directory.  See also **--copy-dest** and **--link-**
                  **dest**.
    
                  NOTE: beginning with version 3.1.0, rsync will remove a
                  file from a non-empty destination hierarchy if an exact
                  match is found in one of the compare-dest hierarchies
                  (making the end result more closely match a fresh copy).
    
           **--copy-dest=DIR**
                  This option behaves like **--compare-dest** , but rsync will
                  also copy unchanged files found in _DIR_ to the destination
                  directory using a local copy.  This is useful for doing
                  transfers to a new destination while leaving existing files
                  intact, and then doing a flash-cutover when all files have
                  been successfully transferred.
    
                  Multiple **--copy-dest** directories may be provided, which
                  will cause rsync to search the list in the order specified
                  for an unchanged file.  If a match is not found, a basis
                  file from one of the _DIRs_ will be selected to try to speed
                  up the transfer.
    
                  If _DIR_ is a relative path, it is relative to the
                  destination directory.  See also **--compare-dest** and **--link-**
                  **dest**.
    
           **--link-dest=DIR**
                  This option behaves like **--copy-dest** , but unchanged files
                  are hard linked from _DIR_ to the destination directory.  The
                  files must be identical in all preserved attributes (e.g.
                  permissions, possibly ownership) in order for the files to
                  be linked together.  An example:
    
                      rsync -av --link-dest=$PWD/prior_dir host:src_dir/ new_dir/
    
                  If files aren't linking, double-check their attributes.
                  Also check if some attributes are getting forced outside of
                  rsync's control, such a mount option that squishes root to
                  a single user, or mounts a removable drive with generic
                  ownership (such as OS X's "Ignore ownership on this volume"
                  option).
    
                  Beginning in version 2.6.4, multiple **--link-dest**
                  directories may be provided, which will cause rsync to
                  search the list in the order specified for an exact match
                  (there is a limit of 20 such directories).  If a match is
                  found that differs only in attributes, a local copy is made
                  and the attributes updated.  If a match is not found, a
                  basis file from one of the _DIRs_ will be selected to try to
                  speed up the transfer.
    
                  This option works best when copying into an empty
                  destination hierarchy, as existing files may get their
                  attributes tweaked, and that can affect alternate
                  destination files via hard-links.  Also, itemizing of
                  changes can get a bit muddled.  Note that prior to version
                  3.1.0, an alternate-directory exact match would never be
                  found (nor linked into the destination) when a destination
                  file already exists.
    
                  Note that if you combine this option with **--ignore-times** ,
                  rsync will not link any files together because it only
                  links identical files together as a substitute for
                  transferring the file, never as an additional check after
                  the file is updated.
    
                  If _DIR_ is a relative path, it is relative to the
                  destination directory.  See also **--compare-dest** and **--copy-**
                  **dest**.
    
                  Note that rsync versions prior to 2.6.1 had a bug that
                  could prevent **--link-dest** from working properly for a non-
                  super-user when **--owner**(**-o**) was specified (or implied).
                  You can work-around this bug by avoiding the **-o** option (or
                  using **--no-o**) when sending to an old rsync.
    
           **--compress** , **-z**
                  With this option, rsync compresses the file data as it is
                  sent to the destination machine, which reduces the amount
                  of data being transmitted -- something that is useful over
                  a slow connection.
    
                  Rsync supports multiple compression methods and will choose
                  one for you unless you force the choice using the
                  **--compress-choice**(**--zc**) option.
    
                  Run **rsync --version** to see the default compress list
                  compiled into your version.
    
                  When both sides of the transfer are at least 3.2.0, rsync
                  chooses the first algorithm in the client's list of choices
                  that is also in the server's list of choices.  If no common
                  compress choice is found, rsync exits with an error.  If
                  the remote rsync is too old to support checksum
                  negotiation, its list is assumed to be "zlib".
    
                  The default order can be customized by setting the
                  environment variable **RSYNC_COMPRESS_LIST** to a space-
                  separated list of acceptable compression names.  If the
                  string contains a "**&** " character, it is separated into the
                  "client string & server string", otherwise the same string
                  applies to both.  If the string (or string portion)
                  contains no non-whitespace characters, the default compress
                  list is used.  Any unknown compression names are discarded
                  from the list, but a list with only invalid names results
                  in a failed negotiation.
    
                  There are some older rsync versions that were configured to
                  reject a **-z** option and require the use of **-zz** because their
                  compression library was not compatible with the default
                  zlib compression method.  You can usually ignore this
                  weirdness unless the rsync server complains and tells you
                  to specify **-zz**.
    
           **--compress-choice=STR** , **--zc=STR**
                  This option can be used to override the automatic
                  negotiation of the compression algorithm that occurs when
                  **--compress** is used.  The option implies **--compress** unless
                  "none" was specified, which instead implies **--no-compress**.
    
                  The compression options that you may be able to use are:
    
                  o      **zstd**
    
                  o      **lz4**
    
                  o      **zlibx**
    
                  o      **zlib**
    
                  o      **none**
    
                  Run **rsync --version** to see the default compress list
                  compiled into your version (which may differ from the list
                  above).
    
                  Note that if you see an error about an option named **--old-**
                  **compress** or **--new-compress** , this is rsync trying to send
                  the **--compress-choice=zlib** or **--compress-choice=zlibx**
                  option in a backward-compatible manner that more rsync
                  versions understand.  This error indicates that the older
                  rsync version on the server will not allow you to force the
                  compression type.
    
                  Note that the "zlibx" compression algorithm is just the
                  "zlib" algorithm with matched data excluded from the
                  compression stream (to try to make it more compatible with
                  an external zlib implementation).
    
           **--compress-level=NUM** , **--zl=NUM**
                  Explicitly set the compression level to use (see
                  **--compress** , **-z**) instead of letting it default.  The
                  **--compress** option is implied as long as the level chosen is
                  not a "don't compress" level for the compression algorithm
                  that is in effect (e.g. zlib compression treats level 0 as
                  "off").
    
                  The level values vary depending on the checksum in effect.
                  Because rsync will negotiate a checksum choice by default
                  (when the remote rsync is new enough), it can be good to
                  combine this option with a **--compress-choice**(**--zc**) option
                  unless you're sure of the choice in effect.  For example:
    
                      rsync -aiv --zc=zstd --zl=22 host:src/ dest/
    
                  For zlib & zlibx compression the valid values are from 1 to
                  9 with 6 being the default.  Specifying **--zl=0** turns
                  compression off, and specifying **--zl=-1** chooses the default
                  level of 6.
    
                  For zstd compression the valid values are from -131072 to
                  22 with 3 being the default. Specifying 0 chooses the
                  default of 3.
    
                  For lz4 compression there are no levels, so the value is
                  always 0.
    
                  If you specify a too-large or too-small value, the number
                  is silently limited to a valid value.  This allows you to
                  specify something like **--zl=999999999** and be assured that
                  you'll end up with the maximum compression level no matter
                  what algorithm was chosen.
    
                  If you want to know the compression level that is in
                  effect, specify **--debug=nstr** to see the "negotiated string"
                  results.  This will report something like
                  "**Client compress: zstd (level 3)** " (along with the checksum
                  choice in effect).
    
           **--skip-compress=LIST**
                  **NOTE:** no compression method currently supports per-file
                  compression changes, so this option has no effect.
    
                  Override the list of file suffixes that will be compressed
                  as little as possible.  Rsync sets the compression level on
                  a per-file basis based on the file's suffix.  If the
                  compression algorithm has an "off" level, then no
                  compression occurs for those files.  Other algorithms that
                  support changing the streaming level on-the-fly will have
                  the level minimized to reduces the CPU usage as much as
                  possible for a matching file.
    
                  The **LIST** should be one or more file suffixes (without the
                  dot) separated by slashes (**/**).  You may specify an empty
                  string to indicate that no files should be skipped.
    
                  Simple character-class matching is supported: each must
                  consist of a list of letters inside the square brackets
                  (e.g. no special classes, such as "[:alpha:]", are
                  supported, and '-' has no special meaning).
    
                  The characters asterisk (*****) and question-mark (**?**) have no
                  special meaning.
    
                  Here's an example that specifies 6 suffixes to skip (since
                  1 of the 5 rules matches 2 suffixes):
    
                      --skip-compress=gz/jpg/mp[34]/7z/bz2
    
                  The default file suffixes in the skip-compress list in this
                  version of rsync are:
    
                      3g2 3gp 7z aac ace apk avi bz2 deb dmg ear f4v flac flv
                      gpg gz iso jar jpeg jpg lrz lz lz4 lzma lzo m1a m1v m2a
                      m2ts m2v m4a m4b m4p m4r m4v mka mkv mov mp1 mp2 mp3
                      mp4 mpa mpeg mpg mpv mts odb odf odg odi odm odp ods
                      odt oga ogg ogm ogv ogx opus otg oth otp ots ott oxt
                      png qt rar rpm rz rzip spx squashfs sxc sxd sxg sxm sxw
                      sz tbz tbz2 tgz tlz ts txz tzo vob war webm webp xz z
                      zip zst
    
                  This list will be replaced by your **--skip-compress** list in
                  all but one situation: a copy from a daemon rsync will add
                  your skipped suffixes to its list of non-compressing files
                  (and its list may be configured to a different default).
    
           **--numeric-ids**
                  With this option rsync will transfer numeric group and user
                  IDs rather than using user and group names and mapping them
                  at both ends.
    
                  By default rsync will use the username and groupname to
                  determine what ownership to give files.  The special uid 0
                  and the special group 0 are never mapped via user/group
                  names even if the **--numeric-ids** option is not specified.
    
                  If a user or group has no name on the source system or it
                  has no match on the destination system, then the numeric ID
                  from the source system is used instead.  See also the
                  **use chroot** setting in the rsyncd.conf manpage for some
                  comments on how the chroot setting affects rsync's ability
                  to look up the names of the users and groups and what you
                  can do about it.
    
           **--usermap=STRING** , **--groupmap=STRING**
                  These options allow you to specify users and groups that
                  should be mapped to other values by the receiving side.
                  The **STRING** is one or more **FROM** :**TO** pairs of values separated
                  by commas.  Any matching **FROM** value from the sender is
                  replaced with a **TO** value from the receiver.  You may
                  specify usernames or user IDs for the **FROM** and **TO** values,
                  and the **FROM** value may also be a wild-card string, which
                  will be matched against the sender's names (wild-cards do
                  NOT match against ID numbers, though see below for why a
                  '***** ' matches everything).  You may instead specify a range
                  of ID numbers via an inclusive range: LOW-HIGH.  For
                  example:
    
                      --usermap=0-99:nobody,wayne:admin,*:normal --groupmap=usr:1,1:usr
    
                  The first match in the list is the one that is used.  You
                  should specify all your user mappings using a single
                  **--usermap** option, and/or all your group mappings using a
                  single **--groupmap** option.
    
                  Note that the sender's name for the 0 user and group are
                  not transmitted to the receiver, so you should either match
                  these values using a 0, or use the names in effect on the
                  receiving side (typically "root").  All other **FROM** names
                  match those in use on the sending side.  All **TO** names match
                  those in use on the receiving side.
    
                  Any IDs that do not have a name on the sending side are
                  treated as having an empty name for the purpose of
                  matching.  This allows them to be matched via a "***** " or
                  using an empty name.  For instance:
    
                      --usermap=:nobody --groupmap=*:nobody
    
                  When the **--numeric-ids** option is used, the sender does not
                  send any names, so all the IDs are treated as having an
                  empty name.  This means that you will need to specify
                  numeric **FROM** values if you want to map these nameless IDs
                  to different values.
    
                  For the **--usermap** option to work, the receiver will need to
                  be running as a super-user (see also the **--super** and
                  **--fake-super** options).  For the **--groupmap** option to work,
                  the receiver will need to have permissions to set that
                  group.
    
                  Starting with rsync 3.2.4, the **--usermap** option implies the
                  **--owner**(**-o**) option while the **--groupmap** option implies the
                  **--group**(**-g**) option (since rsync needs to have those
                  options enabled for the mapping options to work).
    
                  An older rsync client may need to use **-s** to avoid a
                  complaint about wildcard characters, but a modern rsync
                  handles this automatically.
    
           **--chown=USER:GROUP**
                  This option forces all files to be owned by USER with group
                  GROUP.  This is a simpler interface than using **--usermap** &
                  **--groupmap** directly, but it is implemented using those
                  options internally so they cannot be mixed.  If either the
                  USER or GROUP is empty, no mapping for the omitted
                  user/group will occur.  If GROUP is empty, the trailing
                  colon may be omitted, but if USER is empty, a leading colon
                  must be supplied.
    
                  If you specify "**--chown=foo:bar** ", this is exactly the same
                  as specifying "**--usermap=*:foo --groupmap=*:bar** ", only
                  easier (and with the same implied **--owner** and/or **--group**
                  options).
    
                  An older rsync client may need to use **-s** to avoid a
                  complaint about wildcard characters, but a modern rsync
                  handles this automatically.
    
           **--timeout=SECONDS**
                  This option allows you to set a maximum I/O timeout in
                  seconds.  If no data is transferred for the specified time
                  then rsync will exit.  The default is 0, which means no
                  timeout.
    
           **--contimeout=SECONDS**
                  This option allows you to set the amount of time that rsync
                  will wait for its connection to an rsync daemon to succeed.
                  If the timeout is reached, rsync exits with an error.
    
           **--address=ADDRESS**
                  By default rsync will bind to the wildcard address when
                  connecting to an rsync daemon.  The **--address** option allows
                  you to specify a specific IP address (or hostname) to bind
                  to.
    
                  See also the daemon version of the **--address** option.
    
           **--port=PORT**
                  This specifies an alternate TCP port number to use rather
                  than the default of 873.  This is only needed if you are
                  using the double-colon (::) syntax to connect with an rsync
                  daemon (since the URL syntax has a way to specify the port
                  as a part of the URL).
    
                  See also the daemon version of the **--port** option.
    
           **--sockopts=OPTIONS**
                  This option can provide endless fun for people who like to
                  tune their systems to the utmost degree.  You can set all
                  sorts of socket options which may make transfers faster (or
                  slower!).  Read the manpage for the **setsockopt()** system
                  call for details on some of the options you may be able to
                  set.  By default no special socket options are set.  This
                  only affects direct socket connections to a remote rsync
                  daemon.
    
                  See also the daemon version of the **--sockopts** option.
    
           **--blocking-io**
                  This tells rsync to use blocking I/O when launching a
                  remote shell transport.  If the remote shell is either rsh
                  or remsh, rsync defaults to using blocking I/O, otherwise
                  it defaults to using non-blocking I/O. (Note that ssh
                  prefers non-blocking I/O.)
    
           **--outbuf=MODE**
                  This sets the output buffering mode.  The mode can be None
                  (aka Unbuffered), Line, or Block (aka Full).  You may
                  specify as little as a single letter for the mode, and use
                  upper or lower case.
    
                  The main use of this option is to change Full buffering to
                  Line buffering when rsync's output is going to a file or
                  pipe.
    
           **--itemize-changes** , **-i**
                  Requests a simple itemized list of the changes that are
                  being made to each file, including attribute changes.  This
                  is exactly the same as specifying **--out-format='%i %n%L'**.
                  If you repeat the option, unchanged files will also be
                  output, but only if the receiving rsync is at least version
                  2.6.7 (you can use **-vv** with older versions of rsync, but
                  that also turns on the output of other verbose messages).
    
                  The "%i" escape has a cryptic output that is 11 letters
                  long.  The general format is like the string **YXcstpoguax** ,
                  where **Y** is replaced by the type of update being done, **X** is
                  replaced by the file-type, and the other letters represent
                  attributes that may be output if they are being modified.
    
                  The update types that replace the **Y** are as follows:
    
                  o      A **< **means that a file is being transferred to the
                         remote host (sent).
    
                  o      A **> **means that a file is being transferred to the
                         local host (received).
    
                  o      A **c** means that a local change/creation is occurring
                         for the item (such as the creation of a directory or
                         the changing of a symlink, etc.).
    
                  o      A **h** means that the item is a hard link to another
                         item (requires **--hard-links**).
    
                  o      A **.** means that the item is not being updated (though
                         it might have attributes that are being modified).
    
                  o      A ***** means that the rest of the itemized-output area
                         contains a message (e.g. "deleting").
    
                  The file-types that replace the **X** are: **f** for a file, a **d**
                  for a directory, an **L** for a symlink, a **D** for a device, and
                  a **S** for a special file (e.g. named sockets and fifos).
    
                  The other letters in the string indicate if some attributes
                  of the file have changed, as follows:
    
                  o      "**.** " - the attribute is unchanged.
    
                  o      "**+** " - the file is newly created.
    
                  o      " " - all the attributes are unchanged (all dots
                         turn to spaces).
    
                  o      "**?** " - the change is unknown (when the remote rsync
                         is old).
    
                  o      A letter indicates an attribute is being updated.
    
                  The attribute that is associated with each letter is as
                  follows:
    
                  o      A **c** means either that a regular file has a different
                         checksum (requires **--checksum**) or that a symlink,
                         device, or special file has a changed value.  Note
                         that if you are sending files to an rsync prior to
                         3.0.1, this change flag will be present only for
                         checksum-differing regular files.
    
                  o      A **s** means the size of a regular file is different
                         and will be updated by the file transfer.
    
                  o      A **t** means the modification time is different and is
                         being updated to the sender's value (requires
                         **--times**).  An alternate value of **T** means that the
                         modification time will be set to the transfer time,
                         which happens when a file/symlink/device is updated
                         without **--times** and when a symlink is changed and
                         the receiver can't set its time. (Note: when using
                         an rsync 3.0.0 client, you might see the **s** flag
                         combined with **t** instead of the proper **T** flag for
                         this time-setting failure.)
    
                  o      A **p** means the permissions are different and are
                         being updated to the sender's value (requires
                         **--perms**).
    
                  o      An **o** means the owner is different and is being
                         updated to the sender's value (requires **--owner** and
                         super-user privileges).
    
                  o      A **g** means the group is different and is being
                         updated to the sender's value (requires **--group** and
                         the authority to set the group).
    
                  o
    
                         o      A **u** |**n** |**b** indicates the following information:
    
                                **u** means the access (use) time is different
                                and is being updated to the sender's value
                                (requires **--atimes**)
    
                         o      **n** means the create time (newness) is
                                different and is being updated to the
                                sender's value (requires **--crtimes**)
    
                         o      **b** means that both the access and create times
                                are being updated
    
                  o      The **a** means that the ACL information is being
                         changed.
    
                  o      The **x** means that the extended attribute information
                         is being changed.
    
                  One other output is possible: when deleting files, the "%i"
                  will output the string "***deleting** " for each item that is
                  being removed (assuming that you are talking to a recent
                  enough rsync that it logs deletions instead of outputting
                  them as a verbose message).
    
           **--out-format=FORMAT**
                  This allows you to specify exactly what the rsync client
                  outputs to the user on a per-update basis.  The format is a
                  text string containing embedded single-character escape
                  sequences prefixed with a percent (%) character.  A default
                  format of "%n%L" is assumed if either **--info=name** or **-v** is
                  specified (this tells you just the name of the file and, if
                  the item is a link, where it points).  For a full list of
                  the possible escape characters, see the **log format** setting
                  in the rsyncd.conf manpage.
    
                  Specifying the **--out-format** option implies the **--info=name**
                  option, which will mention each file, dir, etc. that gets
                  updated in a significant way (a transferred file, a
                  recreated symlink/device, or a touched directory).  In
                  addition, if the itemize-changes escape (%i) is included in
                  the string (e.g. if the **--itemize-changes** option was used),
                  the logging of names increases to mention any item that is
                  changed in any way (as long as the receiving side is at
                  least 2.6.4).  See the **--itemize-changes** option for a
                  description of the output of "%i".
    
                  Rsync will output the out-format string prior to a file's
                  transfer unless one of the transfer-statistic escapes is
                  requested, in which case the logging is done at the end of
                  the file's transfer.  When this late logging is in effect
                  and **--progress** is also specified, rsync will also output
                  the name of the file being transferred prior to its
                  progress information (followed, of course, by the out-
                  format output).
    
           **--log-file=FILE**
                  This option causes rsync to log what it is doing to a file.
                  This is similar to the logging that a daemon does, but can
                  be requested for the client side and/or the server side of
                  a non-daemon transfer.  If specified as a client option,
                  transfer logging will be enabled with a default format of
                  "%i %n%L".  See the **--log-file-format** option if you wish to
                  override this.
    
                  Here's an example command that requests the remote side to
                  log what is happening:
    
                      rsync -av --remote-option=--log-file=/tmp/rlog src/ dest/
    
                  This is very useful if you need to debug why a connection
                  is closing unexpectedly.
    
                  See also the daemon version of the **--log-file** option.
    
           **--log-file-format=FORMAT**
                  This allows you to specify exactly what per-update logging
                  is put into the file specified by the **--log-file** option
                  (which must also be specified for this option to have any
                  effect).  If you specify an empty string, updated files
                  will not be mentioned in the log file.  For a list of the
                  possible escape characters, see the **log format** setting in
                  the rsyncd.conf manpage.
    
                  The default FORMAT used if **--log-file** is specified and this
                  option is not is '%i %n%L'.
    
                  See also the daemon version of the **--log-file-format**
                  option.
    
           **--stats**
                  This tells rsync to print a verbose set of statistics on
                  the file transfer, allowing you to tell how effective
                  rsync's delta-transfer algorithm is for your data.  This
                  option is equivalent to **--info=stats2** if combined with 0 or
                  1 **-v** options, or **--info=stats3** if combined with 2 or more
                  **-v** options.
    
                  The current statistics are as follows:
    
                  o      **Number of files** is the count of all "files" (in the
                         generic sense), which includes directories,
                         symlinks, etc.  The total count will be followed by
                         a list of counts by filetype (if the total is non-
                         zero).  For example: "(reg: 5, dir: 3, link: 2, dev:
                         1, special: 1)" lists the totals for regular files,
                         directories, symlinks, devices, and special files.
                         If any of value is 0, it is completely omitted from
                         the list.
    
                  o      **Number of created files** is the count of how many
                         "files" (generic sense) were created (as opposed to
                         updated).  The total count will be followed by a
                         list of counts by filetype (if the total is non-
                         zero).
    
                  o      **Number of deleted files** is the count of how many
                         "files" (generic sense) were deleted.  The total
                         count will be followed by a list of counts by
                         filetype (if the total is non-zero).  Note that this
                         line is only output if deletions are in effect, and
                         only if protocol 31 is being used (the default for
                         rsync 3.1.x).
    
                  o      **Number of regular files transferred** is the count of
                         normal files that were updated via rsync's delta-
                         transfer algorithm, which does not include dirs,
                         symlinks, etc.  Note that rsync 3.1.0 added the word
                         "regular" into this heading.
    
                  o      **Total file size** is the total sum of all file sizes
                         in the transfer.  This does not count any size for
                         directories or special files, but does include the
                         size of symlinks.
    
                  o      **Total transferred file size** is the total sum of all
                         files sizes for just the transferred files.
    
                  o      **Literal data** is how much unmatched file-update data
                         we had to send to the receiver for it to recreate
                         the updated files.
    
                  o      **Matched data** is how much data the receiver got
                         locally when recreating the updated files.
    
                  o      **File list size** is how big the file-list data was
                         when the sender sent it to the receiver.  This is
                         smaller than the in-memory size for the file list
                         due to some compressing of duplicated data when
                         rsync sends the list.
    
                  o      **File list generation time** is the number of seconds
                         that the sender spent creating the file list.  This
                         requires a modern rsync on the sending side for this
                         to be present.
    
                  o      **File list transfer time** is the number of seconds
                         that the sender spent sending the file list to the
                         receiver.
    
                  o      **Total bytes sent** is the count of all the bytes that
                         rsync sent from the client side to the server side.
    
                  o      **Total bytes received** is the count of all non-message
                         bytes that rsync received by the client side from
                         the server side. "Non-message" bytes means that we
                         don't count the bytes for a verbose message that the
                         server sent to us, which makes the stats more
                         consistent.
    
           **--8-bit-output** , **-8**
                  This tells rsync to leave all high-bit characters unescaped
                  in the output instead of trying to test them to see if
                  they're valid in the current locale and escaping the
                  invalid ones.  All control characters (but never tabs) are
                  always escaped, regardless of this option's setting.
    
                  The escape idiom that started in 2.6.7 is to output a
                  literal backslash (**\**) and a hash (**#**), followed by exactly 3
                  octal digits.  For example, a newline would output as
                  "**\#012** ".  A literal backslash that is in a filename is not
                  escaped unless it is followed by a hash and 3 digits (0-9).
    
           **--human-readable** , **-h**
                  Output numbers in a more human-readable format.  There are
                  3 possible levels:
    
                  1.     output numbers with a separator between each set of
                         3 digits (either a comma or a period, depending on
                         if the decimal point is represented by a period or a
                         comma).
    
                  2.     output numbers in units of 1000 (with a character
                         suffix for larger units -- see below).
    
                  3.     output numbers in units of 1024.
    
                  The default is human-readable level 1.  Each **-h** option
                  increases the level by one.  You can take the level down to
                  0 (to output numbers as pure digits) by specifying the
                  **--no-human-readable**(**--no-h**) option.
    
                  The unit letters that are appended in levels 2 and 3 are: **K**
                  (kilo), **M**(mega), **G**(giga), **T**(tera), or **P**(peta).  For
                  example, a 1234567-byte file would output as 1.23M in
                  level-2 (assuming that a period is your local decimal
                  point).
    
                  Backward compatibility note: versions of rsync prior to
                  3.1.0 do not support human-readable level 1, and they
                  default to level 0.  Thus, specifying one or two **-h** options
                  will behave in a comparable manner in old and new versions
                  as long as you didn't specify a **--no-h** option prior to one
                  or more **-h** options.  See the **--list-only** option for one
                  difference.
    
           **--partial**
                  By default, rsync will delete any partially transferred
                  file if the transfer is interrupted.  In some circumstances
                  it is more desirable to keep partially transferred files.
                  Using the **--partial** option tells rsync to keep the partial
                  file which should make a subsequent transfer of the rest of
                  the file much faster.
    
           **--partial-dir=DIR**
                  This option modifies the behavior of the **--partial** option
                  while also implying that it be enabled.  This enhanced
                  partial-file method puts any partially transferred files
                  into the specified _DIR_ instead of writing the partial file
                  out to the destination file.  On the next transfer, rsync
                  will use a file found in this dir as data to speed up the
                  resumption of the transfer and then delete it after it has
                  served its purpose.
    
                  Note that if **--whole-file** is specified (or implied), any
                  partial-dir files that are found for a file that is being
                  updated will simply be removed (since rsync is sending
                  files without using rsync's delta-transfer algorithm).
    
                  Rsync will create the _DIR_ if it is missing, but just the
                  last dir -- not the whole path.  This makes it easy to use
                  a relative path (such as "**--partial-dir=.rsync-partial** ") to
                  have rsync create the partial-directory in the destination
                  file's directory when it is needed, and then remove it
                  again when the partial file is deleted.  Note that this
                  directory removal is only done for a relative pathname, as
                  it is expected that an absolute path is to a directory that
                  is reserved for partial-dir work.
    
                  If the partial-dir value is not an absolute path, rsync
                  will add an exclude rule at the end of all your existing
                  excludes.  This will prevent the sending of any partial-dir
                  files that may exist on the sending side, and will also
                  prevent the untimely deletion of partial-dir items on the
                  receiving side.  An example: the above **--partial-dir** option
                  would add the equivalent of this "perishable" exclude at
                  the end of any other filter rules: **-f '-p .rsync-partial/'**
    
                  If you are supplying your own exclude rules, you may need
                  to add your own exclude/hide/protect rule for the partial-
                  dir because:
    
                  1.     the auto-added rule may be ineffective at the end of
                         your other rules, or
    
                  2.     you may wish to override rsync's exclude choice.
    
                  For instance, if you want to make rsync clean-up any left-
                  over partial-dirs that may be lying around, you should
                  specify **--delete-after** and add a "risk" filter rule, e.g.
                  **-f 'R .rsync-partial/'**. Avoid using **--delete-before** or
                  **--delete-during** unless you don't need rsync to use any of
                  the left-over partial-dir data during the current run.
    
                  IMPORTANT: the **--partial-dir** should not be writable by
                  other users or it is a security risk!  E.g. AVOID "/tmp"!
    
                  You can also set the partial-dir value the
                  **RSYNC_PARTIAL_DIR** environment variable.  Setting this in
                  the environment does not force **--partial** to be enabled, but
                  rather it affects where partial files go when **--partial** is
                  specified.  For instance, instead of using **--partial-**
                  **dir=.rsync-tmp** along with **--progress** , you could set
                  **RSYNC_PARTIAL_DIR=.rsync-tmp** in your environment and then
                  use the **-P** option to turn on the use of the .rsync-tmp dir
                  for partial transfers.  The only times that the **--partial**
                  option does not look for this environment value are:
    
                  1.     when **--inplace** was specified (since **--inplace**
                         conflicts with **--partial-dir**), and
    
                  2.     when **--delay-updates** was specified (see below).
    
                  When a modern rsync resumes the transfer of a file in the
                  partial-dir, that partial file is now updated in-place
                  instead of creating yet another tmp-file copy (so it maxes
                  out at dest + tmp instead of dest + partial + tmp).  This
                  requires both ends of the transfer to be at least version
                  3.2.0.
    
                  For the purposes of the daemon-config's "**refuse options** "
                  setting, **--partial-dir** does _not_ imply **--partial**.  This is
                  so that a refusal of the **--partial** option can be used to
                  disallow the overwriting of destination files with a
                  partial transfer, while still allowing the safer idiom
                  provided by **--partial-dir**.
    
           **--delay-updates**
                  This option puts the temporary file from each updated file
                  into a holding directory until the end of the transfer, at
                  which time all the files are renamed into place in rapid
                  succession.  This attempts to make the updating of the
                  files a little more atomic.  By default the files are
                  placed into a directory named **.~tmp~** in each file's
                  destination directory, but if you've specified the
                  **--partial-dir** option, that directory will be used instead.
                  See the comments in the **--partial-dir** section for a
                  discussion of how this **.~tmp~** dir will be excluded from the
                  transfer, and what you can do if you want rsync to cleanup
                  old **.~tmp~** dirs that might be lying around.  Conflicts with
                  **--inplace** and **--append**.
    
                  This option implies **--no-inc-recursive** since it needs the
                  full file list in memory in order to be able to iterate
                  over it at the end.
    
                  This option uses more memory on the receiving side (one bit
                  per file transferred) and also requires enough free disk
                  space on the receiving side to hold an additional copy of
                  all the updated files.  Note also that you should not use
                  an absolute path to **--partial-dir** unless:
    
                  1.     there is no chance of any of the files in the
                         transfer having the same name (since all the updated
                         files will be put into a single directory if the
                         path is absolute), and
    
                  2.     there are no mount points in the hierarchy (since
                         the delayed updates will fail if they can't be
                         renamed into place).
    
                  See also the "atomic-rsync" python script in the "support"
                  subdir for an update algorithm that is even more atomic (it
                  uses **--link-dest** and a parallel hierarchy of files).
    
           **--prune-empty-dirs** , **-m**
                  This option tells the receiving rsync to get rid of empty
                  directories from the file-list, including nested
                  directories that have no non-directory children.  This is
                  useful for avoiding the creation of a bunch of useless
                  directories when the sending rsync is recursively scanning
                  a hierarchy of files using include/exclude/filter rules.
    
                  This option can still leave empty directories on the
                  receiving side if you make use of TRANSFER_RULES.
    
                  Because the file-list is actually being pruned, this option
                  also affects what directories get deleted when a delete is
                  active.  However, keep in mind that excluded files and
                  directories can prevent existing items from being deleted
                  due to an exclude both hiding source files and protecting
                  destination files.  See the perishable filter-rule option
                  for how to avoid this.
    
                  You can prevent the pruning of certain empty directories
                  from the file-list by using a global "protect" filter.  For
                  instance, this option would ensure that the directory
                  "emptydir" was kept in the file-list:
    
                      --filter 'protect emptydir/'
    
                  Here's an example that copies all .pdf files in a
                  hierarchy, only creating the necessary destination
                  directories to hold the .pdf files, and ensures that any
                  superfluous files and directories in the destination are
                  removed (note the hide filter of non-directories being used
                  instead of an exclude):
    
                      rsync -avm --del --include='*.pdf' -f 'hide,! */' src/ dest
    
                  If you didn't want to remove superfluous destination files,
                  the more time-honored options of
                  **--include='*/' --exclude='*'** would work fine in place of
                  the hide-filter (if that is more natural to you).
    
           **--progress**
                  This option tells rsync to print information showing the
                  progress of the transfer.  This gives a bored user
                  something to watch.  With a modern rsync this is the same
                  as specifying **--info=flist2,name,progress** , but any user-
                  supplied settings for those info flags takes precedence
                  (e.g.  **--info=flist0 --progress**).
    
                  While rsync is transferring a regular file, it updates a
                  progress line that looks like this:
    
                      782448  63%  110.64kB/s    0:00:04
    
                  In this example, the receiver has reconstructed 782448
                  bytes or 63% of the sender's file, which is being
                  reconstructed at a rate of 110.64 kilobytes per second, and
                  the transfer will finish in 4 seconds if the current rate
                  is maintained until the end.
    
                  These statistics can be misleading if rsync's delta-
                  transfer algorithm is in use.  For example, if the sender's
                  file consists of the basis file followed by additional
                  data, the reported rate will probably drop dramatically
                  when the receiver gets to the literal data, and the
                  transfer will probably take much longer to finish than the
                  receiver estimated as it was finishing the matched part of
                  the file.
    
                  When the file transfer finishes, rsync replaces the
                  progress line with a summary line that looks like this:
    
                      1,238,099 100%  146.38kB/s    0:00:08  (xfr#5, to-chk=169/396)
    
                  In this example, the file was 1,238,099 bytes long in
                  total, the average rate of transfer for the whole file was
                  146.38 kilobytes per second over the 8 seconds that it took
                  to complete, it was the 5th transfer of a regular file
                  during the current rsync session, and there are 169 more
                  files for the receiver to check (to see if they are up-to-
                  date or not) remaining out of the 396 total files in the
                  file-list.
    
                  In an incremental recursion scan, rsync won't know the
                  total number of files in the file-list until it reaches the
                  ends of the scan, but since it starts to transfer files
                  during the scan, it will display a line with the text "ir-
                  chk" (for incremental recursion check) instead of "to-chk"
                  until the point that it knows the full size of the list, at
                  which point it will switch to using "to-chk".  Thus, seeing
                  "ir-chk" lets you know that the total count of files in the
                  file list is still going to increase (and each time it
                  does, the count of files left to check will increase by the
                  number of the files added to the list).
    
           **-P** The **-P** option is equivalent to "**--partial --progress** ".  Its
                  purpose is to make it much easier to specify these two
                  options for a long transfer that may be interrupted.
    
                  There is also a **--info=progress2** option that outputs
                  statistics based on the whole transfer, rather than
                  individual files.  Use this flag without outputting a
                  filename (e.g. avoid **-v** or specify **--info=name0**) if you
                  want to see how the transfer is doing without scrolling the
                  screen with a lot of names. (You don't need to specify the
                  **--progress** option in order to use **--info=progress2**.)
    
                  Finally, you can get an instant progress report by sending
                  rsync a signal of either SIGINFO or SIGVTALRM.  On BSD
                  systems, a SIGINFO is generated by typing a Ctrl+T (Linux
                  doesn't currently support a SIGINFO signal).  When the
                  client-side process receives one of those signals, it sets
                  a flag to output a single progress report which is output
                  when the current file transfer finishes (so it may take a
                  little time if a big file is being handled when the signal
                  arrives).  A filename is output (if needed) followed by the
                  **--info=progress2** format of progress info.  If you don't
                  know which of the 3 rsync processes is the client process,
                  it's OK to signal all of them (since the non-client
                  processes ignore the signal).
    
                  CAUTION: sending SIGVTALRM to an older rsync (pre-3.2.0)
                  will kill it.
    
           **--password-file=FILE**
                  This option allows you to provide a password for accessing
                  an rsync daemon via a file or via standard input if **FILE** is
                  **-**.  The file should contain just the password on the first
                  line (all other lines are ignored).  Rsync will exit with
                  an error if **FILE** is world readable or if a root-run rsync
                  command finds a non-root-owned file.
    
                  This option does not supply a password to a remote shell
                  transport such as ssh; to learn how to do that, consult the
                  remote shell's documentation.  When accessing an rsync
                  daemon using a remote shell as the transport, this option
                  only comes into effect after the remote shell finishes its
                  authentication (i.e. if you have also specified a password
                  in the daemon's config file).
    
           **--early-input=FILE**
                  This option allows rsync to send up to 5K of data to the
                  "early exec" script on its stdin.  One possible use of this
                  data is to give the script a secret that can be used to
                  mount an encrypted filesystem (which you should unmount in
                  the the "post-xfer exec" script).
    
                  The daemon must be at least version 3.2.1.
    
           **--list-only**
                  This option will cause the source files to be listed
                  instead of transferred.  This option is inferred if there
                  is a single source arg and no destination specified, so its
                  main uses are:
    
                  1.     to turn a copy command that includes a destination
                         arg into a file-listing command, or
    
                  2.     to be able to specify more than one source arg.
                         Note: be sure to include the destination.
    
                  CAUTION: keep in mind that a source arg with a wild-card is
                  expanded by the shell into multiple args, so it is never
                  safe to try to specify a single wild-card arg to try to
                  infer this option. A safe example is:
    
                      rsync -av --list-only foo* dest/
    
                  This option always uses an output format that looks similar
                  to this:
    
                      drwxrwxr-x          4,096 2022/09/30 12:53:11 support
                      -rw-rw-r--             80 2005/01/11 10:37:37 support/Makefile
    
                  The only option that affects this output style is (as of
                  3.1.0) the **--human-readable**(**-h**) option.  The default is to
                  output sizes as byte counts with digit separators (in a
                  14-character-width column).  Specifying at least one **-h**
                  option makes the sizes output with unit suffixes.  If you
                  want old-style bytecount sizes without digit separators
                  (and an 11-character-width column) use **--no-h**.
    
                  Compatibility note: when requesting a remote listing of
                  files from an rsync that is version 2.6.3 or older, you may
                  encounter an error if you ask for a non-recursive listing.
                  This is because a file listing implies the **--dirs** option
                  w/o **--recursive** , and older rsyncs don't have that option.
                  To avoid this problem, either specify the **--no-dirs** option
                  (if you don't need to expand a directory's content), or
                  turn on recursion and exclude the content of
                  subdirectories: **-r --exclude='/*/*'**.
    
           **--bwlimit=RATE**
                  This option allows you to specify the maximum transfer rate
                  for the data sent over the socket, specified in units per
                  second.  The RATE value can be suffixed with a string to
                  indicate a size multiplier, and may be a fractional value
                  (e.g. **--bwlimit=1.5m**).  If no suffix is specified, the
                  value will be assumed to be in units of 1024 bytes (as if
                  "K" or "KiB" had been appended).  See the **--max-size** option
                  for a description of all the available suffixes.  A value
                  of 0 specifies no limit.
    
                  For backward-compatibility reasons, the rate limit will be
                  rounded to the nearest KiB unit, so no rate smaller than
                  1024 bytes per second is possible.
    
                  Rsync writes data over the socket in blocks, and this
                  option both limits the size of the blocks that rsync
                  writes, and tries to keep the average transfer rate at the
                  requested limit.  Some burstiness may be seen where rsync
                  writes out a block of data and then sleeps to bring the
                  average rate into compliance.
    
                  Due to the internal buffering of data, the **--progress**
                  option may not be an accurate reflection on how fast the
                  data is being sent.  This is because some files can show up
                  as being rapidly sent when the data is quickly buffered,
                  while other can show up as very slow when the flushing of
                  the output buffer occurs.  This may be fixed in a future
                  version.
    
                  See also the daemon version of the **--bwlimit** option.
    
           **--stop-after=MINS** , (**--time-limit=MINS**)
                  This option tells rsync to stop copying when the specified
                  number of minutes has elapsed.
    
                  For maximal flexibility, rsync does not communicate this
                  option to the remote rsync since it is usually enough that
                  one side of the connection quits as specified.  This allows
                  the option's use even when only one side of the connection
                  supports it.  You can tell the remote side about the time
                  limit using **--remote-option**(**-M**), should the need arise.
    
                  The **--time-limit** version of this option is deprecated.
    
           **--stop-at=y-m-dTh:m**
                  This option tells rsync to stop copying when the specified
                  point in time has been reached. The date & time can be
                  fully specified in a numeric format of year-month-
                  dayThour:minute (e.g. 2000-12-31T23:59) in the local
                  timezone.  You may choose to separate the date numbers
                  using slashes instead of dashes.
    
                  The value can also be abbreviated in a variety of ways,
                  such as specifying a 2-digit year and/or leaving off
                  various values.  In all cases, the value will be taken to
                  be the next possible point in time where the supplied
                  information matches.  If the value specifies the current
                  time or a past time, rsync exits with an error.
    
                  For example, "1-30" specifies the next January 30th (at
                  midnight local time), "14:00" specifies the next 2 P.M.,
                  "1" specifies the next 1st of the month at midnight, "31"
                  specifies the next month where we can stop on its 31st day,
                  and ":59" specifies the next 59th minute after the hour.
    
                  For maximal flexibility, rsync does not communicate this
                  option to the remote rsync since it is usually enough that
                  one side of the connection quits as specified.  This allows
                  the option's use even when only one side of the connection
                  supports it.  You can tell the remote side about the time
                  limit using **--remote-option**(**-M**), should the need arise.
                  Do keep in mind that the remote host may have a different
                  default timezone than your local host.
    
           **--fsync**
                  Cause the receiving side to fsync each finished file.  This
                  may slow down the transfer, but can help to provide peace
                  of mind when updating critical files.
    
           **--write-batch=FILE**
                  Record a file that can later be applied to another
                  identical destination with **--read-batch**.  See the "BATCH
                  MODE" section for details, and also the **--only-write-batch**
                  option.
    
                  This option overrides the negotiated checksum & compress
                  lists and always negotiates a choice based on old-school
                  md5/md4/zlib choices.  If you want a more modern choice,
                  use the **--checksum-choice**(**--cc**) and/or **--compress-choice**
                  (**--zc**) options.
    
           **--only-write-batch=FILE**
                  Works like **--write-batch** , except that no updates are made
                  on the destination system when creating the batch.  This
                  lets you transport the changes to the destination system
                  via some other means and then apply the changes via **--read-**
                  **batch**.
    
                  Note that you can feel free to write the batch directly to
                  some portable media: if this media fills to capacity before
                  the end of the transfer, you can just apply that partial
                  transfer to the destination and repeat the whole process to
                  get the rest of the changes (as long as you don't mind a
                  partially updated destination system while the multi-update
                  cycle is happening).
    
                  Also note that you only save bandwidth when pushing changes
                  to a remote system because this allows the batched data to
                  be diverted from the sender into the batch file without
                  having to flow over the wire to the receiver (when pulling,
                  the sender is remote, and thus can't write the batch).
    
           **--read-batch=FILE**
                  Apply all of the changes stored in FILE, a file previously
                  generated by **--write-batch**.  If _FILE_ is **-** , the batch data
                  will be read from standard input. See the "BATCH MODE"
                  section for details.
    
           **--protocol=NUM**
                  Force an older protocol version to be used.  This is useful
                  for creating a batch file that is compatible with an older
                  version of rsync.  For instance, if rsync 2.6.4 is being
                  used with the **--write-batch** option, but rsync 2.6.3 is what
                  will be used to run the **--read-batch** option, you should use
                  "--protocol=28" when creating the batch file to force the
                  older protocol version to be used in the batch file
                  (assuming you can't upgrade the rsync on the reading
                  system).
    
           **--iconv=CONVERT_SPEC**
                  Rsync can convert filenames between character sets using
                  this option.  Using a CONVERT_SPEC of "." tells rsync to
                  look up the default character-set via the locale setting.
                  Alternately, you can fully specify what conversion to do by
                  giving a local and a remote charset separated by a comma in
                  the order **--iconv=LOCAL,REMOTE** , e.g. **--iconv=utf8,iso88591**.
                  This order ensures that the option will stay the same
                  whether you're pushing or pulling files.  Finally, you can
                  specify either **--no-iconv** or a CONVERT_SPEC of "-" to turn
                  off any conversion.  The default setting of this option is
                  site-specific, and can also be affected via the **RSYNC_ICONV**
                  environment variable.
    
                  For a list of what charset names your local iconv library
                  supports, you can run "**iconv --list** ".
    
                  If you specify the **--secluded-args**(**-s**) option, rsync will
                  translate the filenames you specify on the command-line
                  that are being sent to the remote host.  See also the
                  **--files-from** option.
    
                  Note that rsync does not do any conversion of names in
                  filter files (including include/exclude files).  It is up
                  to you to ensure that you're specifying matching rules that
                  can match on both sides of the transfer.  For instance, you
                  can specify extra include/exclude rules if there are
                  filename differences on the two sides that need to be
                  accounted for.
    
                  When you pass an **--iconv** option to an rsync daemon that
                  allows it, the daemon uses the charset specified in its
                  "charset" configuration parameter regardless of the remote
                  charset you actually pass.  Thus, you may feel free to
                  specify just the local charset for a daemon transfer (e.g.
                  **--iconv=utf8**).
    
           **--ipv4** , **-4** or **--ipv6** , **-6**
                  Tells rsync to prefer IPv4/IPv6 when creating sockets or
                  running ssh.  This affects sockets that rsync has direct
                  control over, such as the outgoing socket when directly
                  contacting an rsync daemon, as well as the forwarding of
                  the **-4** or **-6** option to ssh when rsync can deduce that ssh
                  is being used as the remote shell.  For other remote shells
                  you'll need to specify the "**--rsh SHELL -4** " option directly
                  (or whatever IPv4/IPv6 hint options it uses).
    
                  See also the daemon version of these options.
    
                  If rsync was compiled without support for IPv6, the **--ipv6**
                  option will have no effect.  The **rsync --version** output
                  will contain "**no IPv6** " if is the case.
    
           **--checksum-seed=NUM**
                  Set the checksum seed to the integer NUM.  This 4 byte
                  checksum seed is included in each block and MD4 file
                  checksum calculation (the more modern MD5 file checksums
                  don't use a seed).  By default the checksum seed is
                  generated by the server and defaults to the current **time**().
                  This option is used to set a specific checksum seed, which
                  is useful for applications that want repeatable block
                  checksums, or in the case where the user wants a more
                  random checksum seed.  Setting NUM to 0 causes rsync to use
                  the default of **time**() for checksum seed.
    


## DAEMON OPTIONS



           The options allowed when starting an rsync daemon are as follows:
    
           **--daemon**
                  This tells rsync that it is to run as a daemon.  The daemon
                  you start running may be accessed using an rsync client
                  using the **host::module** or **rsync://host/module/** syntax.
    
                  If standard input is a socket then rsync will assume that
                  it is being run via inetd, otherwise it will detach from
                  the current terminal and become a background daemon.  The
                  daemon will read the config file (rsyncd.conf) on each
                  connect made by a client and respond to requests
                  accordingly.
    
                  See the rsyncd.conf(5) manpage for more details.
    
           **--address=ADDRESS**
                  By default rsync will bind to the wildcard address when run
                  as a daemon with the **--daemon** option.  The **--address** option
                  allows you to specify a specific IP address (or hostname)
                  to bind to.  This makes virtual hosting possible in
                  conjunction with the **--config** option.
    
                  See also the address global option in the rsyncd.conf
                  manpage and the client version of the **--address** option.
    
           **--bwlimit=RATE**
                  This option allows you to specify the maximum transfer rate
                  for the data the daemon sends over the socket.  The client
                  can still specify a smaller **--bwlimit** value, but no larger
                  value will be allowed.
    
                  See the client version of the **--bwlimit** option for some
                  extra details.
    
           **--config=FILE**
                  This specifies an alternate config file than the default.
                  This is only relevant when **--daemon** is specified.  The
                  default is /etc/rsyncd.conf unless the daemon is running
                  over a remote shell program and the remote user is not the
                  super-user; in that case the default is rsyncd.conf in the
                  current directory (typically $HOME).
    
           **--dparam=OVERRIDE** , **-M**
                  This option can be used to set a daemon-config parameter
                  when starting up rsync in daemon mode.  It is equivalent to
                  adding the parameter at the end of the global settings
                  prior to the first module's definition.  The parameter
                  names can be specified without spaces, if you so desire.
                  For instance:
    
                      rsync --daemon -M pidfile=/path/rsync.pid
    
           **--no-detach**
                  When running as a daemon, this option instructs rsync to
                  not detach itself and become a background process.  This
                  option is required when running as a service on Cygwin, and
                  may also be useful when rsync is supervised by a program
                  such as **daemontools** or AIX's **System Resource Controller**.
                  **--no-detach** is also recommended when rsync is run under a
                  debugger.  This option has no effect if rsync is run from
                  inetd or sshd.
    
           **--port=PORT**
                  This specifies an alternate TCP port number for the daemon
                  to listen on rather than the default of 873.
    
                  See also the client version of the **--port** option and the
                  port global setting in the rsyncd.conf manpage.
    
           **--log-file=FILE**
                  This option tells the rsync daemon to use the given log-
                  file name instead of using the "**log file** " setting in the
                  config file.
    
                  See also the client version of the **--log-file** option.
    
           **--log-file-format=FORMAT**
                  This option tells the rsync daemon to use the given FORMAT
                  string instead of using the "**log format** " setting in the
                  config file.  It also enables "**transfer logging** " unless the
                  string is empty, in which case transfer logging is turned
                  off.
    
                  See also the client version of the **--log-file-format**
                  option.
    
           **--sockopts**
                  This overrides the **socket options** setting in the
                  rsyncd.conf file and has the same syntax.
    
                  See also the client version of the **--sockopts** option.
    
           **--verbose** , **-v**
                  This option increases the amount of information the daemon
                  logs during its startup phase.  After the client connects,
                  the daemon's verbosity level will be controlled by the
                  options that the client used and the "**max verbosity** "
                  setting in the module's config section.
    
                  See also the client version of the **--verbose** option.
    
           **--ipv4** , **-4** or **--ipv6** , **-6**
                  Tells rsync to prefer IPv4/IPv6 when creating the incoming
                  sockets that the rsync daemon will use to listen for
                  connections.  One of these options may be required in older
                  versions of Linux to work around an IPv6 bug in the kernel
                  (if you see an "address already in use" error when nothing
                  else is using the port, try specifying **--ipv6** or **--ipv4**
                  when starting the daemon).
    
                  See also the client version of these options.
    
                  If rsync was compiled without support for IPv6, the **--ipv6**
                  option will have no effect.  The **rsync --version** output
                  will contain "**no IPv6** " if is the case.
    
           **--help** , **-h**
                  When specified after **--daemon** , print a short help page
                  describing the options available for starting an rsync
                  daemon.
    


## FILTER RULES



           The filter rules allow for custom control of several aspects of
           how files are handled:
    
           o      Control which files the sending side puts into the file
                  list that describes the transfer hierarchy
    
           o      Control which files the receiving side protects from
                  deletion when the file is not in the sender's file list
    
           o      Control which extended attribute names are skipped when
                  copying xattrs
    
           The rules are either directly specified via option arguments or
           they can be read in from one or more files.  The filter-rule files
           can even be a part of the hierarchy of files being copied,
           affecting different parts of the tree in different ways.
    
       **SIMPLE INCLUDE/EXCLUDE RULES**
           We will first cover the basics of how include & exclude rules
           affect what files are transferred, ignoring any deletion side-
           effects.  Filter rules mainly affect the contents of directories
           that rsync is "recursing" into, but they can also affect a top-
           level item in the transfer that was specified as a argument.
    
           The default for any unmatched file/dir is for it to be included in
           the transfer, which puts the file/dir into the sender's file list.
           The use of an exclude rule causes one or more matching files/dirs
           to be left out of the sender's file list.  An include rule can be
           used to limit the effect of an exclude rule that is matching too
           many files.
    
           The order of the rules is important because the first rule that
           matches is the one that takes effect.  Thus, if an early rule
           excludes a file, no include rule that comes after it can have any
           effect. This means that you must place any include overrides
           somewhere prior to the exclude that it is intended to limit.
    
           When a directory is excluded, all its contents and sub-contents
           are also excluded.  The sender doesn't scan through any of it at
           all, which can save a lot of time when skipping large unneeded
           sub-trees.
    
           It is also important to understand that the include/exclude rules
           are applied to every file and directory that the sender is
           recursing into. Thus, if you want a particular deep file to be
           included, you have to make sure that none of the directories that
           must be traversed on the way down to that file are excluded or
           else the file will never be discovered to be included. As an
           example, if the directory "**a/path** " was given as a transfer
           argument and you want to ensure that the file
           "**a/path/down/deep/wanted.txt** " is a part of the transfer, then the
           sender must not exclude the directories "**a/path** ", "**a/path/down** ",
           or "**a/path/down/deep** " as it makes it way scanning through the file
           tree.
    
           When you are working on the rules, it can be helpful to ask rsync
           to tell you what is being excluded/included and why.  Specifying
           **--debug=FILTER** or (when pulling files) **-M--debug=FILTER** turns on
           level 1 of the FILTER debug information that will output a message
           any time that a file or directory is included or excluded and
           which rule it matched.  Beginning in 3.2.4 it will also warn if a
           filter rule has trailing whitespace, since an exclude of "foo "
           (with a trailing space) will not exclude a file named "foo".
    
           Exclude and include rules can specify wildcard PATTERN MATCHING
           RULES (similar to shell wildcards) that allow you to match things
           like a file suffix or a portion of a filename.
    
           A rule can be limited to only affecting a directory by putting a
           trailing slash onto the filename.
    
       **SIMPLE INCLUDE/EXCLUDE EXAMPLE**
           With the following file tree created on the sending side:
    
               mkdir x/
               touch x/file.txt
               mkdir x/y/
               touch x/y/file.txt
               touch x/y/zzz.txt
               mkdir x/z/
               touch x/z/file.txt
    
           Then the following rsync command will transfer the file
           "**x/y/file.txt** " and the directories needed to hold it, resulting in
           the path "**/tmp/x/y/file.txt** " existing on the remote host:
    
               rsync -ai -f'+ x/' -f'+ x/y/' -f'+ x/y/file.txt' -f'- *' x host:/tmp/
    
           Aside: this copy could also have been accomplished using the **-R**
           option (though the 2 commands behave differently if deletions are
           enabled):
    
               rsync -aiR x/y/file.txt host:/tmp/
    
           The following command does not need an include of the "x"
           directory because it is not a part of the transfer (note the
           trailing slash).  Running this command would copy just
           "**/tmp/x/file.txt** " because the "y" and "z" dirs get excluded:
    
               rsync -ai -f'+ file.txt' -f'- *' x/ host:/tmp/x/
    
           This command would omit the zzz.txt file while copying "x" and
           everything else it contains:
    
               rsync -ai -f'- zzz.txt' x host:/tmp/
    
       **FILTER RULES WHEN DELETING**
           By default the include & exclude filter rules affect both the
           sender (as it creates its file list) and the receiver (as it
           creates its file lists for calculating deletions).  If no delete
           option is in effect, the receiver skips creating the delete-
           related file lists.  This two-sided default can be manually
           overridden so that you are only specifying sender rules or
           receiver rules, as described in the FILTER RULES IN DEPTH section.
    
           When deleting, an exclude protects a file from being removed on
           the receiving side while an include overrides that protection
           (putting the file at risk of deletion). The default is for a file
           to be at risk -- its safety depends on it matching a corresponding
           file from the sender.
    
           An example of the two-sided exclude effect can be illustrated by
           the copying of a C development directory between 2 systems.  When
           doing a touch-up copy, you might want to skip copying the built
           executable and the **.o** files (sender hide) so that the receiving
           side can build their own and not lose any object files that are
           already correct (receiver protect).  For instance:
    
               rsync -ai --del -f'- *.o' -f'- cmd' src host:/dest/
    
           Note that using **-f'-p *.o'** is even better than **-f'- *.o'** if there
           is a chance that the directory structure may have changed.  The
           "p" modifier is discussed in FILTER RULE MODIFIERS.
    
           One final note, if your shell doesn't mind unexpanded wildcards,
           you could simplify the typing of the filter options by using an
           underscore in place of the space and leaving off the quotes.  For
           instance, **-f -_*.o -f -_cmd**(and similar) could be used instead of
           the filter options above.
    
       **FILTER RULES IN DEPTH**
           Rsync supports old-style include/exclude rules and new-style
           filter rules.  The older rules are specified using **--include** and
           **--exclude** as well as the **--include-from** and **--exclude-from**. These
           are limited in behavior but they don't require a "-" or "+"
           prefix.  An old-style exclude rule is turned into a "**- name** "
           filter rule (with no modifiers) and an old-style include rule is
           turned into a "**+ name** " filter rule (with no modifiers).
    
           Rsync builds an ordered list of filter rules as specified on the
           command-line and/or read-in from files.  New style filter rules
           have the following syntax:
    
               RULE [PATTERN_OR_FILENAME]
               RULE,MODIFIERS [PATTERN_OR_FILENAME]
    
           You have your choice of using either short or long RULE names, as
           described below.  If you use a short-named rule, the ','
           separating the RULE from the MODIFIERS is optional.  The PATTERN
           or FILENAME that follows (when present) must come after either a
           single space or an underscore (_). Any additional spaces and/or
           underscores are considered to be a part of the pattern name.  Here
           are the available rule prefixes:
    
           **exclude, '-'**
                  specifies an exclude pattern that (by default) is both a
                  **hide** and a **protect**.
    
           **include, '+'**
                  specifies an include pattern that (by default) is both a
                  **show** and a **risk**.
    
           **merge, '.'**
                  specifies a merge-file on the client side to read for more
                  rules.
    
           **dir-merge, ':'**
                  specifies a per-directory merge-file.  Using this kind of
                  filter rule requires that you trust the sending side's
                  filter checking, so it has the side-effect mentioned under
                  the **--trust-sender** option.
    
           **hide, 'H'**
                  specifies a pattern for hiding files from the transfer.
                  Equivalent to a sender-only exclude, so **-f'H foo'** could
                  also be specified as **-f'-s foo'**.
    
           **show, 'S'**
                  files that match the pattern are not hidden. Equivalent to
                  a sender-only include, so **-f'S foo'** could also be specified
                  as **-f'+s foo'**.
    
           **protect, 'P'**
                  specifies a pattern for protecting files from deletion.
                  Equivalent to a receiver-only exclude, so **-f'P foo'** could
                  also be specified as **-f'-r foo'**.
    
           **risk, 'R'**
                  files that match the pattern are not protected. Equivalent
                  to a receiver-only include, so **-f'R foo'** could also be
                  specified as **-f'+r foo'**.
    
           **clear, '!'**
                  clears the current include/exclude list (takes no arg)
    
           When rules are being read from a file (using merge or dir-merge),
           empty lines are ignored, as are whole-line comments that start
           with a '**#** ' (filename rules that contain a hash character are
           unaffected).
    
           Note also that the **--filter** , **--include** , and **--exclude** options take
           one rule/pattern each.  To add multiple ones, you can repeat the
           options on the command-line, use the merge-file syntax of the
           **--filter** option, or the **--include-from** / **--exclude-from** options.
    
       **PATTERN MATCHING RULES**
           Most of the rules mentioned above take an argument that specifies
           what the rule should match.  If rsync is recursing through a
           directory hierarchy, keep in mind that each pattern is matched
           against the name of every directory in the descent path as rsync
           finds the filenames to send.
    
           The matching rules for the pattern argument take several forms:
    
           o      If a pattern contains a **/**(not counting a trailing slash)
                  or a "****** " (which can match a slash), then the pattern is
                  matched against the full pathname, including any leading
                  directories within the transfer.  If the pattern doesn't
                  contain a (non-trailing) **/** or a "****** ", then it is matched
                  only against the final component of the filename or
                  pathname. For example, **foo** means that the final path
                  component must be "foo" while **foo/bar** would match the last
                  2 elements of the path (as long as both elements are within
                  the transfer).
    
           o      A pattern that ends with a **/** only matches a directory, not
                  a regular file, symlink, or device.
    
           o      A pattern that starts with a **/** is anchored to the start of
                  the transfer path instead of the end.  For example, **/foo/****
                  or **/foo/bar/**** match only leading elements in the path.  If
                  the rule is read from a per-directory filter file, the
                  transfer path being matched will begin at the level of the
                  filter file instead of the top of the transfer.  See the
                  section on ANCHORING INCLUDE/EXCLUDE PATTERNS for a full
                  discussion of how to specify a pattern that matches at the
                  root of the transfer.
    
           Rsync chooses between doing a simple string match and wildcard
           matching by checking if the pattern contains one of these three
           wildcard characters: '***** ', '**?** ', and '**[** ' :
    
           o      a '**?** ' matches any single character except a slash (**/**).
    
           o      a '***** ' matches zero or more non-slash characters.
    
           o      a '****** ' matches zero or more characters, including slashes.
    
           o      a '**[** ' introduces a character class, such as **[a-z]** or
                  **[[:alpha:]]** , that must match one character.
    
           o      a trailing ******* in the pattern is a shorthand that allows
                  you to match a directory and all its contents using a
                  single rule.  For example, specifying "**dir_name/***** " will
                  match both the "dir_name" directory (as if "**dir_name/** " had
                  been specified) and everything in the directory (as if
                  "**dir_name/**** " had been specified).
    
           o      a backslash can be used to escape a wildcard character, but
                  it is only interpreted as an escape character if at least
                  one wildcard character is present in the match pattern. For
                  instance, the pattern "**foo\bar** " matches that single
                  backslash literally, while the pattern "**foo\bar*** " would
                  need to be changed to "**foo\\bar*** " to avoid the "**\b** "
                  becoming just "b".
    
           Here are some examples of exclude/include matching:
    
           o      Option **-f'- *.o'** would exclude all filenames ending with **.o**
    
           o      Option **-f'- /foo'** would exclude a file (or directory) named
                  foo in the transfer-root directory
    
           o      Option **-f'- foo/'** would exclude any directory named foo
    
           o      Option **-f'- foo/*/bar'** would exclude any file/dir named bar
                  which is at two levels below a directory named foo (if foo
                  is in the transfer)
    
           o      Option **-f'- /foo/**/bar'** would exclude any file/dir named
                  bar that was two or more levels below a top-level directory
                  named foo (note that /foo/bar is **not** excluded by this)
    
           o      Options **-f'+ */' -f'+ *.c' -f'- *'** would include all
                  directories and .c source files but nothing else
    
           o      Options **-f'+ foo/' -f'+ foo/bar.c' -f'- *'** would include
                  only the foo directory and foo/bar.c (the foo directory
                  must be explicitly included or it would be excluded by the
                  "**- *** ")
    
       **FILTER RULE MODIFIERS**
           The following modifiers are accepted after an include (+) or
           exclude (-) rule:
    
           o      A **/** specifies that the include/exclude rule should be
                  matched against the absolute pathname of the current item.
                  For example, **-f'-/ /etc/passwd'** would exclude the passwd
                  file any time the transfer was sending files from the
                  "/etc" directory, and "-/ subdir/foo" would always exclude
                  "foo" when it is in a dir named "subdir", even if "foo" is
                  at the root of the current transfer.
    
           o      A **!** specifies that the include/exclude should take effect
                  if the pattern fails to match.  For instance, **-f'-! */'**
                  would exclude all non-directories.
    
           o      A **C** is used to indicate that all the global CVS-exclude
                  rules should be inserted as excludes in place of the "-C".
                  No arg should follow.
    
           o      An **s** is used to indicate that the rule applies to the
                  sending side.  When a rule affects the sending side, it
                  affects what files are put into the sender's file list.
                  The default is for a rule to affect both sides unless
                  **--delete-excluded** was specified, in which case default
                  rules become sender-side only.  See also the hide (H) and
                  show (S) rules, which are an alternate way to specify
                  sending-side includes/excludes.
    
           o      An **r** is used to indicate that the rule applies to the
                  receiving side.  When a rule affects the receiving side, it
                  prevents files from being deleted.  See the **s** modifier for
                  more info.  See also the protect (P) and risk (R) rules,
                  which are an alternate way to specify receiver-side
                  includes/excludes.
    
           o      A **p** indicates that a rule is perishable, meaning that it is
                  ignored in directories that are being deleted.  For
                  instance, the **--cvs-exclude**(**-C**) option's default rules
                  that exclude things like "CVS" and "***.o** " are marked as
                  perishable, and will not prevent a directory that was
                  removed on the source from being deleted on the
                  destination.
    
           o      An **x** indicates that a rule affects xattr names in xattr
                  copy/delete operations (and is thus ignored when matching
                  file/dir names).  If no xattr-matching rules are specified,
                  a default xattr filtering rule is used (see the **--xattrs**
                  option).
    
       **MERGE-FILE FILTER RULES**
           You can merge whole files into your filter rules by specifying
           either a merge (.) or a dir-merge (:) filter rule (as introduced
           in the FILTER RULES section above).
    
           There are two kinds of merged files -- single-instance ('.') and
           per-directory (':').  A single-instance merge file is read one
           time, and its rules are incorporated into the filter list in the
           place of the "." rule.  For per-directory merge files, rsync will
           scan every directory that it traverses for the named file, merging
           its contents when the file exists into the current list of
           inherited rules.  These per-directory rule files must be created
           on the sending side because it is the sending side that is being
           scanned for the available files to transfer.  These rule files may
           also need to be transferred to the receiving side if you want them
           to affect what files don't get deleted (see PER-DIRECTORY RULES
           AND DELETE below).
    
           Some examples:
    
               merge /etc/rsync/default.rules
               . /etc/rsync/default.rules
               dir-merge .per-dir-filter
               dir-merge,n- .non-inherited-per-dir-excludes
               :n- .non-inherited-per-dir-excludes
    
           The following modifiers are accepted after a merge or dir-merge
           rule:
    
           o      A **-** specifies that the file should consist of only exclude
                  patterns, with no other rule-parsing except for in-file
                  comments.
    
           o      A **+** specifies that the file should consist of only include
                  patterns, with no other rule-parsing except for in-file
                  comments.
    
           o      A **C** is a way to specify that the file should be read in a
                  CVS-compatible manner.  This turns on 'n', 'w', and '-',
                  but also allows the list-clearing token (!) to be
                  specified.  If no filename is provided, ".cvsignore" is
                  assumed.
    
           o      A **e** will exclude the merge-file name from the transfer;
                  e.g.  "dir-merge,e .rules" is like "dir-merge .rules" and
                  "- .rules".
    
           o      An **n** specifies that the rules are not inherited by
                  subdirectories.
    
           o      A **w** specifies that the rules are word-split on whitespace
                  instead of the normal line-splitting.  This also turns off
                  comments.  Note: the space that separates the prefix from
                  the rule is treated specially, so "- foo + bar" is parsed
                  as two rules (assuming that prefix-parsing wasn't also
                  disabled).
    
           o      You may also specify any of the modifiers for the "+" or
                  "-" rules (above) in order to have the rules that are read
                  in from the file default to having that modifier set
                  (except for the **!** modifier, which would not be useful).
                  For instance, "merge,-/ .excl" would treat the contents of
                  .excl as absolute-path excludes, while "dir-merge,s .filt"
                  and ":sC" would each make all their per-directory rules
                  apply only on the sending side.  If the merge rule
                  specifies sides to affect (via the **s** or **r** modifier or
                  both), then the rules in the file must not specify sides
                  (via a modifier or a rule prefix such as **hide**).
    
           Per-directory rules are inherited in all subdirectories of the
           directory where the merge-file was found unless the 'n' modifier
           was used.  Each subdirectory's rules are prefixed to the inherited
           per-directory rules from its parents, which gives the newest rules
           a higher priority than the inherited rules.  The entire set of
           dir-merge rules are grouped together in the spot where the merge-
           file was specified, so it is possible to override dir-merge rules
           via a rule that got specified earlier in the list of global rules.
           When the list-clearing rule ("!") is read from a per-directory
           file, it only clears the inherited rules for the current merge
           file.
    
           Another way to prevent a single rule from a dir-merge file from
           being inherited is to anchor it with a leading slash.  Anchored
           rules in a per-directory merge-file are relative to the merge-
           file's directory, so a pattern "/foo" would only match the file
           "foo" in the directory where the dir-merge filter file was found.
    
           Here's an example filter file which you'd specify via
           **--filter=". file":**
    
               merge /home/user/.global-filter
               - *.gz
               dir-merge .rules
               + *.[ch]
               - *.o
               - foo*
    
           This will merge the contents of the /home/user/.global-filter file
           at the start of the list and also turns the ".rules" filename into
           a per-directory filter file.  All rules read in prior to the start
           of the directory scan follow the global anchoring rules (i.e. a
           leading slash matches at the root of the transfer).
    
           If a per-directory merge-file is specified with a path that is a
           parent directory of the first transfer directory, rsync will scan
           all the parent dirs from that starting point to the transfer
           directory for the indicated per-directory file.  For instance,
           here is a common filter (see **-F**):
    
               --filter=': /.rsync-filter'
    
           That rule tells rsync to scan for the file .rsync-filter in all
           directories from the root down through the parent directory of the
           transfer prior to the start of the normal directory scan of the
           file in the directories that are sent as a part of the transfer.
           (Note: for an rsync daemon, the root is always the same as the
           module's "path".)
    
           Some examples of this pre-scanning for per-directory files:
    
               rsync -avF /src/path/ /dest/dir
               rsync -av --filter=': ../../.rsync-filter' /src/path/ /dest/dir
               rsync -av --filter=': .rsync-filter' /src/path/ /dest/dir
    
           The first two commands above will look for ".rsync-filter" in "/"
           and "/src" before the normal scan begins looking for the file in
           "/src/path" and its subdirectories.  The last command avoids the
           parent-dir scan and only looks for the ".rsync-filter" files in
           each directory that is a part of the transfer.
    
           If you want to include the contents of a ".cvsignore" in your
           patterns, you should use the rule ":C", which creates a dir-merge
           of the .cvsignore file, but parsed in a CVS-compatible manner.
           You can use this to affect where the **--cvs-exclude**(**-C**) option's
           inclusion of the per-directory .cvsignore file gets placed into
           your rules by putting the ":C" wherever you like in your filter
           rules.  Without this, rsync would add the dir-merge rule for the
           .cvsignore file at the end of all your other rules (giving it a
           lower priority than your command-line rules).  For example:
    
               cat <<EOT | rsync -avC --filter='. -' a/ b
               + foo.o
               :C
               - *.old
               EOT
               rsync -avC --include=foo.o -f :C --exclude='*.old' a/ b
    
           Both of the above rsync commands are identical.  Each one will
           merge all the per-directory .cvsignore rules in the middle of the
           list rather than at the end.  This allows their dir-specific rules
           to supersede the rules that follow the :C instead of being
           subservient to all your rules.  To affect the other CVS exclude
           rules (i.e. the default list of exclusions, the contents of
           $HOME/.cvsignore, and the value of $CVSIGNORE) you should omit the
           **-C** command-line option and instead insert a "-C" rule into your
           filter rules; e.g.  "**--filter=-C** ".
    
       **LIST-CLEARING FILTER RULE**
           You can clear the current include/exclude list by using the "!"
           filter rule (as introduced in the FILTER RULES section above).
           The "current" list is either the global list of rules (if the rule
           is encountered while parsing the filter options) or a set of per-
           directory rules (which are inherited in their own sub-list, so a
           subdirectory can use this to clear out the parent's rules).
    
       **ANCHORING INCLUDE/EXCLUDE PATTERNS**
           As mentioned earlier, global include/exclude patterns are anchored
           at the "root of the transfer" (as opposed to per-directory
           patterns, which are anchored at the merge-file's directory).  If
           you think of the transfer as a subtree of names that are being
           sent from sender to receiver, the transfer-root is where the tree
           starts to be duplicated in the destination directory.  This root
           governs where patterns that start with a / match.
    
           Because the matching is relative to the transfer-root, changing
           the trailing slash on a source path or changing your use of the
           **--relative** option affects the path you need to use in your
           matching (in addition to changing how much of the file tree is
           duplicated on the destination host).  The following examples
           demonstrate this.
    
           Let's say that we want to match two source files, one with an
           absolute path of "/home/me/foo/bar", and one with a path of
           "/home/you/bar/baz".  Here is how the various command choices
           differ for a 2-source transfer:
    
               Example cmd: rsync -a /home/me /home/you /dest
               +/- pattern: /me/foo/bar
               +/- pattern: /you/bar/baz
               Target file: /dest/me/foo/bar
               Target file: /dest/you/bar/baz
    
               Example cmd: rsync -a /home/me/ /home/you/ /dest
               +/- pattern: /foo/bar               (note missing "me")
               +/- pattern: /bar/baz               (note missing "you")
               Target file: /dest/foo/bar
               Target file: /dest/bar/baz
    
               Example cmd: rsync -a --relative /home/me/ /home/you /dest
               +/- pattern: /home/me/foo/bar       (note full path)
               +/- pattern: /home/you/bar/baz      (ditto)
               Target file: /dest/home/me/foo/bar
               Target file: /dest/home/you/bar/baz
    
               Example cmd: cd /home; rsync -a --relative me/foo you/ /dest
               +/- pattern: /me/foo/bar      (starts at specified path)
               +/- pattern: /you/bar/baz     (ditto)
               Target file: /dest/me/foo/bar
               Target file: /dest/you/bar/baz
    
           The easiest way to see what name you should filter is to just look
           at the output when using **--verbose** and put a / in front of the
           name (use the **--dry-run** option if you're not yet ready to copy any
           files).
    
       **PER-DIRECTORY RULES AND DELETE**
           Without a delete option, per-directory rules are only relevant on
           the sending side, so you can feel free to exclude the merge files
           themselves without affecting the transfer.  To make this easy, the
           'e' modifier adds this exclude for you, as seen in these two
           equivalent commands:
    
               rsync -av --filter=': .excl' --exclude=.excl host:src/dir /dest
               rsync -av --filter=':e .excl' host:src/dir /dest
    
           However, if you want to do a delete on the receiving side AND you
           want some files to be excluded from being deleted, you'll need to
           be sure that the receiving side knows what files to exclude.  The
           easiest way is to include the per-directory merge files in the
           transfer and use **--delete-after** , because this ensures that the
           receiving side gets all the same exclude rules as the sending side
           before it tries to delete anything:
    
               rsync -avF --delete-after host:src/dir /dest
    
           However, if the merge files are not a part of the transfer, you'll
           need to either specify some global exclude rules (i.e. specified
           on the command line), or you'll need to maintain your own per-
           directory merge files on the receiving side.  An example of the
           first is this (assume that the remote .rules files exclude
           themselves):
    
               rsync -av --filter=': .rules' --filter='. /my/extra.rules'
                  --delete host:src/dir /dest
    
           In the above example the extra.rules file can affect both sides of
           the transfer, but (on the sending side) the rules are subservient
           to the rules merged from the .rules files because they were
           specified after the per-directory merge rule.
    
           In one final example, the remote side is excluding the .rsync-
           filter files from the transfer, but we want to use our own .rsync-
           filter files to control what gets deleted on the receiving side.
           To do this we must specifically exclude the per-directory merge
           files (so that they don't get deleted) and then put rules into the
           local files to control what else should not get deleted.  Like one
           of these commands:
    
               rsync -av --filter=':e /.rsync-filter' --delete \
                   host:src/dir /dest
               rsync -avFF --delete host:src/dir /dest
    


## TRANSFER RULES



           In addition to the FILTER RULES that affect the recursive file
           scans that generate the file list on the sending and (when
           deleting) receiving sides, there are transfer rules. These rules
           affect which files the generator decides need to be transferred
           without the side effects of an exclude filter rule.  Transfer
           rules affect only files and never directories.
    
           Because a transfer rule does not affect what goes into the
           sender's (and receiver's) file list, it cannot have any effect on
           which files get deleted on the receiving side.  For example, if
           the file "foo" is present in the sender's list but its size is
           such that it is omitted due to a transfer rule, the receiving side
           does not request the file.  However, its presence in the file list
           means that a delete pass will not remove a matching file named
           "foo" on the receiving side.  On the other hand, a server-side
           exclude (hide) of the file "foo" leaves the file out of the
           server's file list, and absent a receiver-side exclude (protect)
           the receiver will remove a matching file named "foo" if deletions
           are requested.
    
           Given that the files are still in the sender's file list, the
           **--prune-empty-dirs** option will not judge a directory as being
           empty even if it contains only files that the transfer rules
           omitted.
    
           Similarly, a transfer rule does not have any extra effect on which
           files are deleted on the receiving side, so setting a maximum file
           size for the transfer does not prevent big files from being
           deleted.
    
           Examples of transfer rules include the default "quick check"
           algorithm (which compares size & modify time), the **--update**
           option, the **--max-size** option, the **--ignore-non-existing** option,
           and a few others.
    


## BATCH MODE



           Batch mode can be used to apply the same set of updates to many
           identical systems.  Suppose one has a tree which is replicated on
           a number of hosts.  Now suppose some changes have been made to
           this source tree and those changes need to be propagated to the
           other hosts.  In order to do this using batch mode, rsync is run
           with the write-batch option to apply the changes made to the
           source tree to one of the destination trees.  The write-batch
           option causes the rsync client to store in a "batch file" all the
           information needed to repeat this operation against other,
           identical destination trees.
    
           Generating the batch file once saves having to perform the file
           status, checksum, and data block generation more than once when
           updating multiple destination trees.  Multicast transport
           protocols can be used to transfer the batch update files in
           parallel to many hosts at once, instead of sending the same data
           to every host individually.
    
           To apply the recorded changes to another destination tree, run
           rsync with the read-batch option, specifying the name of the same
           batch file, and the destination tree.  Rsync updates the
           destination tree using the information stored in the batch file.
    
           For your convenience, a script file is also created when the
           write-batch option is used: it will be named the same as the batch
           file with ".sh" appended.  This script file contains a command-
           line suitable for updating a destination tree using the associated
           batch file.  It can be executed using a Bourne (or Bourne-like)
           shell, optionally passing in an alternate destination tree
           pathname which is then used instead of the original destination
           path.  This is useful when the destination tree path on the
           current host differs from the one used to create the batch file.
    
           Examples:
    
               $ rsync --write-batch=foo -a host:/source/dir/ /adest/dir/
               $ scp foo* remote:
               $ ssh remote ./foo.sh /bdest/dir/
    
               $ rsync --write-batch=foo -a /source/dir/ /adest/dir/
               $ ssh remote rsync --read-batch=- -a /bdest/dir/ <foo
    
           In these examples, rsync is used to update /adest/dir/ from
           /source/dir/ and the information to repeat this operation is
           stored in "foo" and "foo.sh".  The host "remote" is then updated
           with the batched data going into the directory /bdest/dir.  The
           differences between the two examples reveals some of the
           flexibility you have in how you deal with batches:
    
           o      The first example shows that the initial copy doesn't have
                  to be local -- you can push or pull data to/from a remote
                  host using either the remote-shell syntax or rsync daemon
                  syntax, as desired.
    
           o      The first example uses the created "foo.sh" file to get the
                  right rsync options when running the read-batch command on
                  the remote host.
    
           o      The second example reads the batch data via standard input
                  so that the batch file doesn't need to be copied to the
                  remote machine first.  This example avoids the foo.sh
                  script because it needed to use a modified **--read-batch**
                  option, but you could edit the script file if you wished to
                  make use of it (just be sure that no other option is trying
                  to use standard input, such as the **--exclude-from=-**
                  option).
    
           Caveats:
    
           The read-batch option expects the destination tree that it is
           updating to be identical to the destination tree that was used to
           create the batch update fileset.  When a difference between the
           destination trees is encountered the update might be discarded
           with a warning (if the file appears to be up-to-date already) or
           the file-update may be attempted and then, if the file fails to
           verify, the update discarded with an error.  This means that it
           should be safe to re-run a read-batch operation if the command got
           interrupted.  If you wish to force the batched-update to always be
           attempted regardless of the file's size and date, use the **-I**
           option (when reading the batch).  If an error occurs, the
           destination tree will probably be in a partially updated state.
           In that case, rsync can be used in its regular (non-batch) mode of
           operation to fix up the destination tree.
    
           The rsync version used on all destinations must be at least as new
           as the one used to generate the batch file.  Rsync will die with
           an error if the protocol version in the batch file is too new for
           the batch-reading rsync to handle.  See also the **--protocol** option
           for a way to have the creating rsync generate a batch file that an
           older rsync can understand.  (Note that batch files changed format
           in version 2.6.3, so mixing versions older than that with newer
           versions will not work.)
    
           When reading a batch file, rsync will force the value of certain
           options to match the data in the batch file if you didn't set them
           to the same as the batch-writing command.  Other options can (and
           should) be changed.  For instance **--write-batch** changes to **--read-**
           **batch** , **--files-from** is dropped, and the **--filter** / **--include** /
           **--exclude** options are not needed unless one of the **--delete**
           options is specified.
    
           The code that creates the BATCH.sh file transforms any
           filter/include/exclude options into a single list that is appended
           as a "here" document to the shell script file.  An advanced user
           can use this to modify the exclude list if a change in what gets
           deleted by **--delete** is desired.  A normal user can ignore this
           detail and just use the shell script as an easy way to run the
           appropriate **--read-batch** command for the batched data.
    
           The original batch mode in rsync was based on "rsync+", but the
           latest version uses a new implementation.
    


## SYMBOLIC LINKS



           Three basic behaviors are possible when rsync encounters a
           symbolic link in the source directory.
    
           By default, symbolic links are not transferred at all.  A message
           "skipping non-regular" file is emitted for any symlinks that
           exist.
    
           If **--links** is specified, then symlinks are added to the transfer
           (instead of being noisily ignored), and the default handling is to
           recreate them with the same target on the destination.  Note that
           **--archive** implies **--links**.
    
           If **--copy-links** is specified, then symlinks are "collapsed" by
           copying their referent, rather than the symlink.
    
           Rsync can also distinguish "safe" and "unsafe" symbolic links.  An
           example where this might be used is a web site mirror that wishes
           to ensure that the rsync module that is copied does not include
           symbolic links to **/etc/passwd** in the public section of the site.
           Using **--copy-unsafe-links** will cause any links to be copied as the
           file they point to on the destination.  Using **--safe-links** will
           cause unsafe links to be omitted by the receiver.  (Note that you
           must specify or imply **--links** for **--safe-links** to have any
           effect.)
    
           Symbolic links are considered unsafe if they are absolute symlinks
           (start with **/**), empty, or if they contain enough ".." components
           to ascend from the top of the transfer.
    
           Here's a summary of how the symlink options are interpreted.  The
           list is in order of precedence, so if your combination of options
           isn't mentioned, use the first line that is a complete subset of
           your options:
    
           **--copy-links**
                  Turn all symlinks into normal files and directories
                  (leaving no symlinks in the transfer for any other options
                  to affect).
    
           **--copy-dirlinks**
                  Turn just symlinks to directories into real directories,
                  leaving all other symlinks to be handled as described
                  below.
    
           **--links --copy-unsafe-links**
                  Turn all unsafe symlinks into files and create all safe
                  symlinks.
    
           **--copy-unsafe-links**
                  Turn all unsafe symlinks into files, noisily skip all safe
                  symlinks.
    
           **--links --safe-links**
                  The receiver skips creating unsafe symlinks found in the
                  transfer and creates the safe ones.
    
           **--links**
                  Create all symlinks.
    
           For the effect of **--munge-links** , see the discussion in that
           option's section.
    
           Note that the **--keep-dirlinks** option does not effect symlinks in
           the transfer but instead affects how rsync treats a symlink to a
           directory that already exists on the receiving side.  See that
           option's section for a warning.
    


## DIAGNOSTICS



           Rsync occasionally produces error messages that may seem a little
           cryptic.  The one that seems to cause the most confusion is
           "protocol version mismatch -- is your shell clean?".
    
           This message is usually caused by your startup scripts or remote
           shell facility producing unwanted garbage on the stream that rsync
           is using for its transport.  The way to diagnose this problem is
           to run your remote shell like this:
    
               ssh remotehost /bin/true > out.dat
    
           then look at out.dat.  If everything is working correctly then
           out.dat should be a zero length file.  If you are getting the
           above error from rsync then you will probably find that out.dat
           contains some text or data.  Look at the contents and try to work
           out what is producing it.  The most common cause is incorrectly
           configured shell startup scripts (such as .cshrc or .profile) that
           contain output statements for non-interactive logins.
    
           If you are having trouble debugging filter patterns, then try
           specifying the **-vv** option.  At this level of verbosity rsync will
           show why each individual file is included or excluded.
    


## EXIT VALUES



           o      **0** - Success
    
           o      **1** - Syntax or usage error
    
           o      **2** - Protocol incompatibility
    
           o      **3** - Errors selecting input/output files, dirs
    
           o
    
                  o      **4** - Requested action not supported. Either:
    
                         an attempt was made to manipulate 64-bit files on a
                         platform that cannot support them
    
                  o      an option was specified that is supported by the
                         client and not by the server
    
           o      **5** - Error starting client-server protocol
    
           o      **6** - Daemon unable to append to log-file
    
           o      **10** - Error in socket I/O
    
           o      **11** - Error in file I/O
    
           o      **12** - Error in rsync protocol data stream
    
           o      **13** - Errors with program diagnostics
    
           o      **14** - Error in IPC code
    
           o      **20** - Received SIGUSR1 or SIGINT
    
           o      **21** - Some error returned by **waitpid()**
    
           o      **22** - Error allocating core memory buffers
    
           o      **23** - Partial transfer due to error
    
           o      **24** - Partial transfer due to vanished source files
    
           o      **25** - The --max-delete limit stopped deletions
    
           o      **30** - Timeout in data send/receive
    
           o      **35** - Timeout waiting for daemon connection
    


## ENVIRONMENT VARIABLES



           **CVSIGNORE**
                  The CVSIGNORE environment variable supplements any ignore
                  patterns in .cvsignore files.  See the **--cvs-exclude** option
                  for more details.
    
           **RSYNC_ICONV**
                  Specify a default **--iconv** setting using this environment
                  variable. First supported in 3.0.0.
    
           **RSYNC_OLD_ARGS**
                  Specify a "1" if you want the **--old-args** option to be
                  enabled by default, a "2" (or more) if you want it to be
                  enabled in the repeated-option state, or a "0" to make sure
                  that it is disabled by default. When this environment
                  variable is set to a non-zero value, it supersedes the
                  **RSYNC_PROTECT_ARGS** variable.
    
                  This variable is ignored if **--old-args** , **--no-old-args** , or
                  **--secluded-args** is specified on the command line.
    
                  First supported in 3.2.4.
    
           **RSYNC_PROTECT_ARGS**
                  Specify a non-zero numeric value if you want the
                  **--secluded-args** option to be enabled by default, or a zero
                  value to make sure that it is disabled by default.
    
                  This variable is ignored if **--secluded-args** , **--no-secluded-**
                  **args** , or **--old-args** is specified on the command line.
    
                  First supported in 3.1.0.  Starting in 3.2.4, this variable
                  is ignored if **RSYNC_OLD_ARGS** is set to a non-zero value.
    
           **RSYNC_RSH**
                  This environment variable allows you to override the
                  default shell used as the transport for rsync.  Command
                  line options are permitted after the command name, just as
                  in the **--rsh**(**-e**) option.
    
           **RSYNC_PROXY**
                  This environment variable allows you to redirect your rsync
                  client to use a web proxy when connecting to an rsync
                  daemon.  You should set **RSYNC_PROXY** to a hostname:port
                  pair.
    
           **RSYNC_PASSWORD**
                  This environment variable allows you to set the password
                  for an rsync **daemon** connection, which avoids the password
                  prompt.  Note that this does **not** supply a password to a
                  remote shell transport such as ssh (consult its
                  documentation for how to do that).
    
           **USER** or **LOGNAME**
                  The USER or LOGNAME environment variables are used to
                  determine the default username sent to an rsync daemon.  If
                  neither is set, the username defaults to "nobody".  If both
                  are set, **USER** takes precedence.
    
           **RSYNC_PARTIAL_DIR**
                  This environment variable specifies the directory to use
                  for a **--partial** transfer without implying that partial
                  transfers be enabled.  See the **--partial-dir** option for
                  full details.
    
           **RSYNC_COMPRESS_LIST**
                  This environment variable allows you to customize the
                  negotiation of the compression algorithm by specifying an
                  alternate order or a reduced list of names.  Use the
                  command **rsync --version** to see the available compression
                  names.  See the **--compress** option for full details.
    
           **RSYNC_CHECKSUM_LIST**
                  This environment variable allows you to customize the
                  negotiation of the checksum algorithm by specifying an
                  alternate order or a reduced list of names.  Use the
                  command **rsync --version** to see the available checksum
                  names.  See the **--checksum-choice** option for full details.
    
           **RSYNC_MAX_ALLOC**
                  This environment variable sets an allocation maximum as if
                  you had used the **--max-alloc** option.
    
           **RSYNC_PORT**
                  This environment variable is not read by rsync, but is
                  instead set in its sub-environment when rsync is running
                  the remote shell in combination with a daemon connection.
                  This allows a script such as **rsync-ssl** to be able to know
                  the port number that the user specified on the command
                  line.
    
           **HOME** This environment variable is used to find the user's
                  default .cvsignore file.
    
           **RSYNC_CONNECT_PROG**
                  This environment variable is mainly used in debug setups to
                  set the program to use when making a daemon connection.
                  See CONNECTING TO AN RSYNC DAEMON for full details.
    
           **RSYNC_SHELL**
                  This environment variable is mainly used in debug setups to
                  set the program to use to run the program specified by
                  **RSYNC_CONNECT_PROG**.  See CONNECTING TO AN RSYNC DAEMON for
                  full details.
    


## FILES



           /etc/rsyncd.conf or rsyncd.conf
    


## BUGS



           o      Times are transferred as *nix time_t values.
    
           o      When transferring to FAT filesystems rsync may re-sync
                  unmodified files.  See the comments on the **--modify-window**
                  option.
    
           o      File permissions, devices, etc. are transferred as native
                  numerical values.
    
           o      See also the comments on the **--delete** option.
    
           Please report bugs! See the web site at 
           ⟨https://rsync.samba.org/⟩.
    


## VERSION



           This manpage is current for version 3.4.1 of rsync.
    


## INTERNAL OPTIONS



           The options **--server** and **--sender** are used internally by rsync,
           and should never be typed by a user under normal circumstances.
           Some awareness of these options may be needed in certain
           scenarios, such as when setting up a login that can only run an
           rsync command.  For instance, the support directory of the rsync
           distribution has an example script named rrsync (for restricted
           rsync) that can be used with a restricted ssh login.
    


## CREDITS



           Rsync is distributed under the GNU General Public License.  See
           the file COPYING for details.
    
           An rsync web site is available at ⟨https://rsync.samba.org/⟩.  The
           site includes an FAQ-O-Matic which may cover questions unanswered
           by this manual page.
    
           The rsync github project is 
           ⟨https://github.com/RsyncProject/rsync⟩.
    
           We would be delighted to hear from you if you like this program.
           Please contact the mailing-list at rsync@lists.samba.org
           ⟨mailto:rsync@lists.samba.org⟩.
    
           This program uses the excellent zlib compression library written
           by Jean-loup Gailly and Mark Adler.
    


## THANKS



           Special thanks go out to: John Van Essen, Matt McCutchen, Wesley
           W. Terpstra, David Dykstra, Jos Backus, Sebastian Krahmer, Martin
           Pool, and our gone-but-not-forgotten compadre, J.W. Schultz.
    
           Thanks also to Richard Brent, Brendan Mackay, Bill Waite, Stephen
           Rothwell and David Bell.  I've probably missed some people, my
           apologies if I have.
    


* * *