# lsof

## NAME



           lsof - list open files
    


## SYNOPSIS



           **lsof**[ **-?abChHlnNOPQRtUvVX**] [ **-A** _A_ ] [ **-c** _c_ ] [ **+c** _c_ ] [ **+|-d** _d_ ]
           [ **+|-D** _D_ ] [ **+|-e** _s_ ] [ **+|-E**] [ **+|-f [cfgGn]**] [ **-F** _[f]_ ] [ **-g**
           _[s]_ ] [ **-i** _[i]_ ] [ **-k** _k_ ] [ **-K** _k_ ] [ **+|-L** _[l]_ ] [ **+|-m** _m_ ] [ **+|-M**
           ] [ **-o** _[o]_ ] [ **-p** _s_ ] [ **+|-r** _[t[m <fmt>]]_ ] [ **-s** _[p:s]_ ] [ **-S** _[t]_ ]
           [ **-T** _[t]_ ] [ **-u** _s_ ] [ **+|-w**] [ **-x** _[fl]_ ] [ **-z** _[z]_ ] [ **-Z** _[Z]_ ] [
           **--**] [_names_]
    


## DESCRIPTION



           _Lsof_ revision  lists on its standard output file information about
           files opened by processes for the following UNIX dialects:
    
           (See the **DISTRIBUTION** section of this manual page for information
           on how to obtain the latest _lsof_ revision.)
    
           An open file may be a regular file, a directory, a block special
           file, a character special file, an executing text reference, a
           library, a stream or a network file (Internet socket, NFS file or
           UNIX domain socket.)  A specific file or all the files in a file
           system may be selected by path.
    
           Instead of a formatted display, _lsof_ will produce output that can
           be parsed by other programs.  See the **-F** , option description, and
           the **OUTPUT FOR OTHER PROGRAMS** section for more information.
    
           In addition to producing a single output list, _lsof_ will run in
           repeat mode.  In repeat mode it will produce output, delay, then
           repeat the output operation until stopped with an interrupt or
           quit signal.  See the **+|-r** _[t[m <fmt>]]_ option description for more
           information.
    


## OPTIONS



           In the absence of any options, _lsof_ lists all open files belonging
           to all active processes.
    
           If any list request option is specified, other list requests must
           be specifically requested - e.g., if **-U** is specified for the
           listing of UNIX socket files, NFS files won't be listed unless **-N**
           is also specified; or if a user list is specified with the **-u**
           option, UNIX domain socket files, belonging to users not in the
           list, won't be listed unless the **-U** option is also specified.
    
           Normally, list options that are specifically stated are ORed -
           i.e., specifying the **-i** option without an address and the **-u** foo
           option produces a listing of all network files OR files belonging
           to processes owned by user ``foo''.  The exceptions are:
    
           1) the `^' (negated) login name or user ID (UID), specified with
              the **-u** option;
    
           2) the `^' (negated) process ID (PID), specified with the **-p**
              option;
    
           3) the `^' (negated) process group ID (PGID), specified with the
              **-g** option;
    
           4) the `^' (negated) command, specified with the **-c** option;
    
           5) the (`^') negated TCP or UDP protocol state names, specified
              with the **-s** _[p:s]_ option.
    
           Since they represent exclusions, they are applied without ORing or
           ANDing and take effect before any other selection criteria are
           applied.
    
           The **-a** option may be used to AND the selections.  For example,
           specifying **-a** , **-U** , and **-u** foo produces a listing of only UNIX
           socket files that belong to processes owned by user ``foo''.
    
           Caution: the **-a** option causes all list selection options to be
           ANDed; it can't be used to cause ANDing of selected pairs of
           selection options by placing it between them, even though its
           placement there is acceptable.  Wherever **-a** is placed, it causes
           the ANDing of all selection options.
    
           Items of the same selection set - command names, file descriptors,
           network addresses, process identifiers, user identifiers, zone
           names, security contexts - are joined in a single ORed set and
           applied before the result participates in ANDing.  Thus, for
           example, specifying **-i** @aaa.bbb, **-i** @ccc.ddd, **-a** , and **-u** fff,ggg will
           select the listing of files that belong to either login ``fff'' OR
           ``ggg'' AND have network connections to either host aaa.bbb OR
           ccc.ddd.
    
           Options may be grouped together following a single prefix -- e.g.,
           the option set ``**-a -b -C** '' may be stated as **-abC**.  However, since
           values are optional following **+|-f** , **-F** , **-g** , **-i** , **+|-L** , **-o** , **+|-r** ,
           **-s** , **-S** , **-T** , **-x** and **-z**.  when you have no values for them be
           careful that the following character isn't ambiguous.  For
           example, **-Fn** might represent the **-F** and **-n** options, or it might
           represent the **n** field identifier character following the **-F**
           option.  When ambiguity is possible, start a new option with a `-'
           character - e.g., ``**-F -n** ''.  If the next option is a file name,
           follow the possibly ambiguous option with ``--'' - e.g., ``**-F --**
           _name_ ''.
    
           Either the `+' or the `-' prefix may be applied to a group of
           options.  Options that don't take on separate meanings for each
           prefix - e.g., **-i** - may be grouped under either prefix.  Thus, for
           example, ``+M -i'' may be stated as ``+Mi'' and the group means
           the same as the separate options.  Be careful of prefix grouping
           when one or more options in the group does take on separate
           meanings under different prefixes - e.g., **+|-M** ; ``-iM'' is not the
           same request as ``-i +M''.  When in doubt, use separate options
           with appropriate prefixes.
    
           **-? -h** These two equivalent options select a usage (help) output
                  list.  _Lsof_ displays a shortened form of this output when
                  it detects an error in the options supplied to it, after it
                  has displayed messages explaining each error.  (Escape the
                  `?' character as your shell requires.)
    
           **-a** causes list selection options to be ANDed, as described
                  above.
    
           **-A** _A_   is available on systems configured for AFS whose AFS kernel
                  code is implemented via dynamic modules.  It allows the
                  _lsof_ user to specify _A_ as an alternate name list file where
                  the kernel addresses of the dynamic modules might be found.
                  See the _lsof_ FAQ (The **FAQ** section gives its location.)  for
                  more information about dynamic modules, their symbols, and
                  how they affect _lsof_.
    
           **-b** causes _lsof_ to avoid kernel functions that might block -
                  lstat(2), readlink(2), and stat(2).
    
                  See the **BLOCKS AND TIMEOUTS** and **AVOIDING KERNEL BLOCKS**
                  sections for information on using this option.
    
           **-c** _c_   selects the listing of files for processes executing the
                  command that begins with the characters of _c_.  Multiple
                  commands may be specified, using multiple **-c** options.  They
                  are joined in a single ORed set before participating in AND
                  option selection.
    
                  If _c_ begins with a `^', then the following characters
                  specify a command name whose processes are to be ignored
                  (excluded.)
    
                  If _c_ begins and ends with a slash ('/'), the characters
                  between the slashes are interpreted as a regular
                  expression.  Shell meta-characters in the regular
                  expression must be quoted to prevent their interpretation
                  by the shell.  The closing slash may be followed by these
                  modifiers:
    
                       b    the regular expression is a basic one.
                       i    ignore the case of letters.
                       x    the regular expression is an extended one
                            (default).
    
                  See the _lsof_ FAQ (The **FAQ** section gives its location.)  for
                  more information on basic and extended regular expressions.
    
                  The simple command specification is tested first.  If that
                  test fails, the command regular expression is applied.  If
                  the simple command test succeeds, the command regular
                  expression test isn't made.  This may result in ``no
                  command found for regex:'' messages when lsof's **-V** option
                  is specified.
    
           **+c** _w_   defines the maximum number of initial characters of the
                  name, supplied by the UNIX dialect, of the UNIX command
                  associated with a process to be printed in the COMMAND
                  column.  (The _lsof_ default is nine.)
    
                  Note that many UNIX dialects do not supply all command name
                  characters to _lsof_ in the files and structures from which
                  _lsof_ obtains command name.  Often dialects limit the number
                  of characters supplied in those sources.  For example,
                  Linux 2.4.27 and Solaris 9 both limit command name length
                  to 16 characters.
    
                  If _w_ is zero ('0'), all command characters supplied to _lsof_
                  by the UNIX dialect will be printed.
    
                  If _w_ is less than the length of the column title,
                  ``COMMAND'', it will be raised to that length.
    
           **-C** disables the reporting of any path name components from the
                  kernel's name cache.  See the **KERNEL NAME CACHE** section for
                  more information.
    
           **+d** _s_   causes _lsof_ to search for all open instances of directory _s_
                  and the files and directories it contains at its top level.
                  **+d** does NOT descend the directory tree, rooted at _s_.  The
                  **+D** _D_ option may be used to request a full-descent directory
                  tree search, rooted at directory _D_.
    
                  Processing of the **+d** option does not follow symbolic links
                  within _s_ unless the **-x** or **-x  l** option is also specified.
                  Nor does it search for open files on file system mount
                  points on subdirectories of _s_ unless the **-x** or **-x  f** option
                  is also specified.
    
                  Note: the authority of the user of this option limits it to
                  searching for files that the user has permission to examine
                  with the system stat(2) function.
    
           **-d** _s_   specifies a list of file descriptors (FDs) to exclude from
                  or include in the output listing.  The file descriptors are
                  specified in the comma-separated set _s_ - e.g., ``cwd,1,3'',
                  ``^6,^2''.  (There should be no spaces in the set.)
    
                  The list is an exclusion list if all entries of the set
                  begin with `^'.  It is an inclusion list if no entry begins
                  with `^'.  Mixed lists are not permitted.
    
                  A file descriptor number range may be in the set as long as
                  neither member is empty, both members are numbers, and the
                  ending member is larger than the starting one - e.g.,
                  ``0-7'' or ``3-10''.  Ranges may be specified for exclusion
                  if they have the `^' prefix - e.g., ``^0-7'' excludes all
                  file descriptors 0 through 7.
    
                  Multiple file descriptor numbers are joined in a single
                  ORed set before participating in AND option selection.
    
                  When there are exclusion and inclusion members in the set,
                  _lsof_ reports them as errors and exits with a non-zero
                  return code.
    
                  See the description of File Descriptor (FD) output values
                  in the **OUTPUT** section for more information on file
                  descriptor names.
    
                  **fd** is a pseudo file descriptor name for specifying the
                  whole range of possible file descriptor numbers.  **fd** does
                  not appear in FD column of output.
    
           **+D** _D_   causes _lsof_ to search for all open instances of directory _D_
                  and all the files and directories it contains to its
                  complete depth.
    
                  Processing of the **+D** option does not follow symbolic links
                  within _D_ unless the **-x** or **-x  l** option is also specified.
                  Nor does it search for open files on file system mount
                  points on subdirectories of _D_ unless the **-x** or **-x  f** option
                  is also specified.
    
                  Note: the authority of the user of this option limits it to
                  searching for files that the user has permission to examine
                  with the system stat(2) function.
    
                  Further note: _lsof_ may process this option slowly and
                  require a large amount of dynamic memory to do it.  This is
                  because it must descend the entire directory tree, rooted
                  at _D_ , calling stat(2) for each file and directory, building
                  a list of all the files it finds, and searching that list
                  for a match with every open file.  When directory _D_ is
                  large, these steps can take a long time, so use this option
                  prudently.
    
           **-D** _D_   directs _lsof's_ use of the device cache file.  The use of
                  this option is sometimes restricted.  See the **DEVICE CACHE**
                  **FILE** section and the sections that follow it for more
                  information on this option.
    
                  **-D** must be followed by a function letter; the function
                  letter may optionally be followed by a path name.  _Lsof_
                  recognizes these function letters:
    
                       **?** - report device cache file paths
                       **b** - build the device cache file
                       **i** - ignore the device cache file
                       **r** - read the device cache file
                       **u** - read and update the device cache file
    
                  The **b** , **r** , and **u** functions, accompanied by a path name, are
                  sometimes restricted.  When these functions are restricted,
                  they will not appear in the description of the **-D** option
                  that accompanies **-h** or **-?** option output.  See the **DEVICE**
                  **CACHE FILE** section and the sections that follow it for more
                  information on these functions and when they're restricted.
    
                  The **?** function reports the read-only and write paths that
                  lsof can use for the device cache file, the names of any
                  environment variables whose values _lsof_ will examine when
                  forming the device cache file path, and the format for the
                  personal device cache file path.  (Escape the `?' character
                  as your shell requires.)
    
                  When available, the **b** , **r** , and **u** functions may be followed
                  by the device cache file's path.  The standard default is
                  _.lsof_hostname_ in the home directory of the real user ID
                  that executes _lsof_ , but this could have been changed when
                  _lsof_ was configured and compiled.  (The output of the **-h**
                  and **-?** options show the current default prefix - e.g.,
                  ``.lsof''.)  The suffix, _hostname_ , is the first component
                  of the host's name returned by gethostname(2).
    
                  When available, the **b** function directs _lsof_ to build a new
                  device cache file at the default or specified path.
    
                  The **i** function directs _lsof_ to ignore the default device
                  cache file and obtain its information about devices via
                  direct calls to the kernel.
    
                  The **r** function directs _lsof_ to read the device cache at the
                  default or specified path, but prevents it from creating a
                  new device cache file when none exists or the existing one
                  is improperly structured.  The **r** function, when specified
                  without a path name, prevents _lsof_ from updating an
                  incorrect or outdated device cache file, or creating a new
                  one in its place.  The **r** function is always available when
                  it is specified without a path name argument; it may be
                  restricted by the permissions of the _lsof_ process.
    
                  When available, the **u** function directs _lsof_ to read the
                  device cache file at the default or specified path, if
                  possible, and to rebuild it, if necessary.  This is the
                  default device cache file function when no **-D** option has
                  been specified.
    
           **+|-e** _s_ exempts the file system whose path name is _s_ from being
                  subjected to kernel function calls that might block.  The
                  **+e** option exempts stat(2), lstat(2) and most readlink(2)
                  kernel function calls.  The **-e** option exempts only stat(2)
                  and lstat(2) kernel function calls.  Multiple file systems
                  may be specified with separate **+|-e** specifications and each
                  may have readlink(2) calls exempted or not.
    
                  This option is currently implemented only for Linux.
    
                  **CAUTION:** this option can easily be mis-applied to other
                  than the file system of interest, because it uses path name
                  rather than the more reliable device and inode numbers.
                  (Device and inode numbers are acquired via the potentially
                  blocking stat(2) kernel call and are thus not available,
                  but see the **+|-m** _m_ option as a possible alternative way to
                  supply device numbers.)  **Use this option with great care**
                  **and fully specify the path name of the file system to be**
                  **exempted.**
    
                  When open files on exempted file systems are reported, it
                  may not be possible to obtain all their information.
                  Therefore, some information columns will be blank, the
                  characters ``UNKN'' preface the values in the TYPE column,
                  and the applicable exemption option is added in parentheses
                  to the end of the NAME column.  (Some device number
                  information might be made available via the **+|-m** _m_ option.)
    
           **+|-E   +E** specifies that Linux pipe, Linux UNIX socket, Linux
                  INET(6) socket closed in a local host, Linux pseudoterminal
                  files, POSIX Message Queueue implementation in Linux, and
                  Linux eventfd should be displayed with endpoint information
                  and the files of the endpoints should also be displayed.
    
                  Note 1: UNIX socket file endpoint information is only
                  available when the features enabled line of **-v** output
                  contains uxsockept, and psudoterminal endpoint information
                  is only available when the features enabled line contains
                  ptyept.
    
                  Note 2: POSIX Message Queue file endpoint information is
                  only available when mqueue file system is mounted.
    
                  Pipe endpoint information is displayed in the NAME column
                  in the form ``_PID,cmd,FDmode_ '', where _PID_ is the endpoint
                  process ID; _cmd_ is the endpoint process command; _FD_ is the
                  endpoint file's descriptor; and _mode_ is the endpoint file's
                  access mode.
    
                  Pseudoterminal endpoint information is displayed in the
                  NAME column as ``->/dev/pts _min PID,cmd,FDmode_ '' or
                  ``_PID,cmd,FDmode_ ''.  The first form is for a master device;
                  the second, for a slave device.  _min_ is a slave device's
                  minor device number; and _PID, cmd, FD_ and _mode_ are the same
                  as with pipe endpoint information.  Note: psudoterminal
                  endpoint information is only available when the features
                  enabled line of **-v** output contains ptyept. In addition,
                  this feature works on Linux kernels above 4.13.0.
    
                  UNIX socket file endpoint information is displayed in the
                  NAME column in the form
                  ``type=_TYPE_ ->INO=_INODE PID,cmd,FDmode_ '', where _TYPE_ is the
                  socket type; _INODE_ is the i-node number of the connected
                  socket; and _PID, cmd, FD_ and _mode_ are the same as with pipe
                  endpoint information.  Note: UNIX socket file endpoint
                  information is available only when the features enabled
                  line of **-v** output contains uxsockept.
    
                  INET socket file endpoint information is inserted to the
                  value at the NAME column in the form
                  `` -> _PID,cmd,FDmode_ '', where _PID, cmd, FD_ and _mode_ are the
                  same as with pipe endpoint information. The endpoint
                  information is available only if the socket is used for
                  local IPC; both endpoints bind to the same local IPv4 or
                  IPv6 address.
    
                  POSIX Message Queue file endpoint information is displayed
                  in the NAME column in the same form as that of pipe.
    
                  eventfd endpoint information is displayed in the NAME
                  column in the same form as that of pipe. This feature works
                  on Linux kernels above 5.2.0.
    
                  Multiple occurrences of this information can appear in a
                  file's NAME column.
    
                  **-E** specifies that endpoint supported files should be
                  displayed with endpoint information, but not the files of
                  the endpoints.
    
           **+|-f [cfgGn]**
                  **f** by itself clarifies how path name arguments are to be
                  interpreted.  When followed by **c** , **f** , **g** , **G** , or **n** in any
                  combination it specifies that the listing of kernel file
                  structure information is to be enabled (`+') or inhibited
                  (`-').
    
                  Normally a path name argument is taken to be a file system
                  name if it matches a mounted-on directory name reported by
                  mount(8), or if it represents a block device, named in the
                  _mount_ output and associated with a mounted directory name.
                  When **+f** is specified, all path name arguments will be taken
                  to be file system names, and _lsof_ will complain if any are
                  not.  This can be useful, for example, when the file system
                  name (mounted-on device) isn't a block device.  This
                  happens for some CD-ROM file systems.
    
                  When **-f** is specified by itself, all path name arguments
                  will be taken to be simple files.  Thus, for example, the
                  ``**-f** -- /'' arguments direct lsof to search for open files
                  with a `/' path name, not all open files in the `/' (root)
                  file system.
    
                  Be careful to make sure **+f** and **-f** are properly terminated
                  and aren't followed by a character (e.g., of the file or
                  file system name) that might be taken as a parameter.  For
                  example, use ``--'' after **+f** and **-f** as in these examples.
    
                       $ lsof +f -- /file/system/name
                       $ lsof -f -- /file/name
    
                  The listing of information from kernel file structures,
                  requested with the **+f [cfgGn]** option form, is normally
                  inhibited, and is not available in whole or part for some
                  dialects - e.g., /proc-based Linux kernels below 2.6.22.
                  When the prefix to **f** is a plus sign (`+'), these characters
                  request file structure information:
    
                       **c** file structure use count (not Linux)
                       **f** file structure address (not Linux)
                       **g** file flag abbreviations (Linux 2.6.22 and up)
    
                            Abbrev.   Flag in C code (see open(2))
    
                            **W** O_WRONLY
                            **RW** O_RDWR
                            **CR** O_CREAT
                            **EXCL** O_EXCL
                            **NTTY** O_NOCTTY
                            **TR** O_TRUNC
                            **AP** O_APPEND
                            **ND** O_NDELAY
                            **SYN** O_SYNC
                            **ASYN** O_ASYNC
                            **DIR** O_DIRECT
                            **DTY** O_DIRECTORY
                            **NFLK** O_NOFOLLOW
                            **NATM** O_NOATIME
                            **DSYN** O_DSYNC
                            **RSYN** O_RSYNC
                            **LG** O_LARGEFILE
                            **CX** O_CLOEXEC
                            **TMPF** O_TMPFILE
    
                       **G** file flags in hexadecimal (Linux 2.6.22 and up)
                       **n** file structure node address (not Linux)
    
                  When the prefix is minus (`-') the same characters disable
                  the listing of the indicated values.
    
                  File structure addresses, use counts, flags, and node
                  addresses may be used to detect more readily identical
                  files inherited by child processes and identical files in
                  use by different processes.  _Lsof_ column output can be
                  sorted by output columns holding the values and listed to
                  identify identical file use, or _lsof_ field output can be
                  parsed by an AWK or Perl post-filter script, or by a C
                  program.
    
           **-F** _f_   specifies a character list, _f_ , that selects the fields to
                  be output for processing by another program, and the
                  character that terminates each output field.  Each field to
                  be output is specified with a single character in _f_.  The
                  field terminator defaults to NL, but may be changed to NUL
                  (000).  See the **OUTPUT FOR OTHER PROGRAMS** section for a
                  description of the field identification characters and the
                  field output process.
    
                  When the field selection character list is empty, all
                  standard fields are selected (except the raw device field,
                  security context and zone field for compatibility reasons)
                  and the NL field terminator is used.
    
                  When the field selection character list contains only a
                  zero (`0'), all fields are selected (except the raw device
                  field for compatibility reasons) and the NUL terminator
                  character is used.
    
                  Other combinations of fields and their associated field
                  terminator character must be set with explicit entries in
                  _f_ , as described in the **OUTPUT FOR OTHER PROGRAMS** section.
    
                  When a field selection character identifies an item _lsof_
                  does not normally list - e.g., PPID, selected with **-R** -
                  specification of the field character - e.g., ``**-FR** '' - also
                  selects the listing of the item.
    
                  When the field selection character list contains the single
                  character `?', _lsof_ will display a help list of the field
                  identification characters.  (Escape the `?' character as
                  your shell requires.)
    
           **-g** _[s]_ excludes or selects the listing of files for the processes
                  whose optional process group IDentification (PGID) numbers
                  are in the comma-separated set _s_ - e.g., ``123'' or
                  ``123,^456''.  (There should be no spaces in the set.)
    
                  PGID numbers that begin with `^' (negation) represent
                  exclusions.
    
                  Multiple PGID numbers are joined in a single ORed set
                  before participating in AND option selection.  However,
                  PGID exclusions are applied without ORing or ANDing and
                  take effect before other selection criteria are applied.
    
                  The **-g** option also enables the output display of PGID
                  numbers.  When specified without a PGID set that's all it
                  does.
    
           **-H** directs lsof to print human readable sizes, e.g. 123.4K
                  456.7M.
    
           **-i** _[i]_ selects the listing of files any of whose Internet address
                  matches the address specified in _i_.  If no address is
                  specified, this option selects the listing of all Internet
                  and x.25 (HP-UX) network files.
    
                  If **-i** _4_ or **-i** _6_ is specified with no following address, only
                  files of the indicated IP version, IPv4 or IPv6, are
                  displayed.  (An IPv6 specification may be used only if the
                  dialects supports IPv6, as indicated by ``[46]'' and
                  ``IPv[46]'' in _lsof's_ **-h** or **-?** output.)  Sequentially
                  specifying **-i** 4, followed by **-i** 6 is the same as specifying
                  **-i** , and vice-versa.  Specifying **-i** 4, or **-i** 6 after **-i** is the
                  same as specifying **-i** 4 or **-i** 6 by itself.
    
                  Multiple addresses (up to a limit of 100) may be specified
                  with multiple **-i** options.  (A port number or service name
                  range is counted as one address.)  They are joined in a
                  single ORed set before participating in AND option
                  selection.
    
                  An Internet address is specified in the form (Items in
                  square brackets are optional.):
    
                  [_46_][_protocol_][@_hostname_ |_hostaddr_][:_service_ |_port_]
    
                  where:
                       _46_ specifies the IP version, IPv4 or IPv6
                            that applies to the following address.
                            '6' may be be specified only if the UNIX
                            dialect supports IPv6.  If neither '4' nor
                            '6' is specified, the following address
                            applies to all IP versions.
                       _protocol_ is a protocol name - **TCP** , **UDP** or **UDPLITE**.
                       _hostname_ is an Internet host name.  Unless a
                            specific IP version is specified, open
                            network files associated with host names
                            of all versions will be selected.
                       _hostaddr_ is a numeric Internet IPv4 address in
                            dot form; or an IPv6 numeric address in
                            colon form, enclosed in brackets, if the
                            UNIX dialect supports IPv6.  When an IP
                            version is selected, only its numeric
                            addresses may be specified.
                       _service_ is an _/etc/services_ name - e.g., **smtp** -
                            or a list of them.
                       _port_ is a port number, or a list of them.
    
                  IPv6 options may be used only if the UNIX dialect supports
                  IPv6.  To see if the dialect supports IPv6, run _lsof_ and
                  specify the **-h** or **-?**(help) option.  If the displayed
                  description of the **-i** option contains ``[46]'' and
                  ``IPv[46]'', IPv6 is supported.
    
                  IPv4 host names and addresses may not be specified if
                  network file selection is limited to IPv6 with **-i** 6.  IPv6
                  host names and addresses may not be specified if network
                  file selection is limited to IPv4 with **-i** 4.  When an open
                  IPv4 network file's address is mapped in an IPv6 address,
                  the open file's type will be IPv6, not IPv4, and its
                  display will be selected by '6', not '4'.
    
                  At least one address component - **4, 6,**_protocol_ , _hostname_ ,
                  _hostaddr_ , or _service_ - must be supplied.  The `@'
                  character, leading the host specification, is always
                  required; as is the `:', leading the port specification.
                  Specify either _hostname_ or _hostaddr_.  Specify either
                  _service_ name list or _port_ number list.  If a _service_ name
                  list is specified, the _protocol_ may also need to be
                  specified if the TCP, UDP and UDPLITE port numbers for the
                  service name are different.  Use any case - lower or upper
                  - for _protocol_.
    
                  _Service_ names and _port_ numbers may be combined in a list
                  whose entries are separated by commas and whose numeric
                  range entries are separated by minus signs.  There may be
                  no embedded spaces, and all service names must belong to
                  the specified _protocol_.  Since service names may contain
                  embedded minus signs, the starting entry of a range can't
                  be a service name; it can be a port number, however.
    
                  Here are some sample addresses:
    
                       -i6 - IPv6 only
                       TCP:25 - TCP and port 25
                       @1.2.3.4 - Internet IPv4 host address 1.2.3.4
                       @[3ffe:1ebc::1]:1234 - Internet IPv6 host address
                            3ffe:1ebc::1, port 1234
                       UDP:who - UDP who service port
                       TCP@lsof.itap:513 - TCP, port 513 and host name lsof.itap
                       tcp@foo:1-10,smtp,99 - TCP, ports 1 through 10,
                            service name _smtp_ , port 99, host name foo
                       tcp@bar:1-smtp - TCP, ports 1 through _smtp_ , host bar
                       :time - either TCP, UDP or UDPLITE time service port
    
           **-K** _k_   selects the listing of tasks (threads) of processes, on
                  dialects where task (thread) reporting is supported.  (If
                  help output - i.e., the output of the **-h** or **-?** options -
                  shows this option, then task (thread) reporting is
                  supported by the dialect.)
    
                  If **-K** is followed by a value, _k_ , it must be ``i''.  That
                  causes _lsof_ to ignore tasks, particularly in the default,
                  list-everything case when no other options are specified.
    
                  When **-K** and **-a** are both specified on Linux, and the tasks
                  of a main process are selected by other options, the main
                  process will also be listed as though it were a task, but
                  without a task ID.  (See the description of the TID column
                  in the **OUTPUT** section.)
    
                  Where the FreeBSD version supports threads, all threads
                  will be listed with their IDs.
    
                  In general threads and tasks inherit the files of the
                  caller, but may close some and open others, so _lsof_ always
                  reports all the open files of threads and tasks.
    
           **-k** _k_   specifies a kernel name list file, _k_ , in place of /vmunix,
                  /mach, etc.  **-k** is not available under AIX on the IBM
                  RISC/System 6000.
    
           **-l** inhibits the conversion of user ID numbers to login names.
                  It is also useful when login name lookup is working
                  improperly or slowly.
    
           **+|-L** _[l]_
                  enables (`+') or disables (`-') the listing of file link
                  counts, where they are available - e.g., they aren't
                  available for sockets, or most FIFOs and pipes.
    
                  When **+L** is specified without a following number, all link
                  counts will be listed.  When **-L** is specified (the default),
                  no link counts will be listed.
    
                  When **+L** is followed by a number, only files having a link
                  count less than that number will be listed.  (No number may
                  follow **-L**.)  A specification of the form ``**+L1** '' will
                  select open files that have been unlinked.  A specification
                  of the form ``**+aL1** _< file_system>_'' will select unlinked
                  open files on the specified file system.
    
                  For other link count comparisons, use field output (**-F**) and
                  a post-processing script or program.
    
           **+|-m** _m_ specifies an alternate kernel memory file or activates
                  mount table supplement processing.
    
                  The option form **-m** _m_ specifies a kernel memory file, _m_ , in
                  place of _/dev/kmem_ or _/dev/mem_ - e.g., a crash dump file.
    
                  The option form **+m** requests that a mount supplement file be
                  written to the standard output file.  All other options are
                  silently ignored.
    
                  There will be a line in the mount supplement file for each
                  mounted file system, containing the mounted file system
                  directory, followed by a single space, followed by the
                  device number in hexadecimal "0x" format - e.g.,
    
                       / 0x801
    
                  _Lsof_ can use the mount supplement file to get device
                  numbers for file systems when it can't get them via stat(2)
                  or lstat(2).
    
                  The option form **+m** _m_ identifies _m_ as a mount supplement
                  file.
    
                  Note: the **+m** and **+m** _m_ options are not available for all
                  supported dialects.  Check the output of _lsof's_ **-h** or **-?**
                  options to see if the **+m** and **+m** _m_ options are available.
    
           **+|-M** Enables (**+**) or disables (**-**) the reporting of portmapper
                  registrations for local TCP, UDP and UDPLITE ports, where
                  port mapping is supported.  (See the last paragraph of this
                  option description for information about where portmapper
                  registration reporting is supported.)
    
                  The default reporting mode is set by the _lsof_ builder with
                  the HASPMAPENABLED #define in the dialect's machine.h
                  header file; _lsof_ is distributed with the HASPMAPENABLED
                  #define deactivated, so portmapper reporting is disabled by
                  default and must be requested with **+M**.  Specifying _lsof's_
                  **-h** or **-?** option will report the default mode.  Disabling
                  portmapper registration when it is already disabled or
                  enabling it when already enabled is acceptable.  When
                  portmapper registration reporting is enabled, _lsof_ displays
                  the portmapper registration (if any) for local TCP, UDP or
                  UDPLITE ports in square brackets immediately following the
                  port numbers or service names - e.g., ``:1234[name]'' or
                  ``:name[100083]''.  The registration information may be a
                  name or number, depending on what the registering program
                  supplied to the portmapper when it registered the port.
    
                  When portmapper registration reporting is enabled, _lsof_ may
                  run a little more slowly or even become blocked when access
                  to the portmapper becomes congested or stopped.  Reverse
                  the reporting mode to determine if portmapper registration
                  reporting is slowing or blocking _lsof_.
    
                  For purposes of portmapper registration reporting _lsof_
                  considers a TCP, UDP or UDPLITE port local if: it is found
                  in the local part of its containing kernel structure; or if
                  it is located in the foreign part of its containing kernel
                  structure and the local and foreign Internet addresses are
                  the same; or if it is located in the foreign part of its
                  containing kernel structure and the foreign Internet
                  address is INADDR_LOOPBACK (127.0.0.1).  This rule may make
                  _lsof_ ignore some foreign ports on machines with multiple
                  interfaces when the foreign Internet address is on a
                  different interface from the local one.
    
                  See the _lsof_ FAQ (The **FAQ** section gives its location.)  for
                  further discussion of portmapper registration reporting
                  issues.
    
                  Portmapper registration reporting is supported only on
                  dialects that have RPC header files.  (Some Linux
                  distributions with GlibC 2.14 do not have them.)  When
                  portmapper registration reporting is supported, the **-h** or
                  **-?** help output will show the **+|-M** option.
    
           **-n** inhibits the conversion of network numbers to host names
                  for network files.  Inhibiting conversion may make _lsof_ run
                  faster.  It is also useful when host name lookup is not
                  working properly.
    
           **-N** selects the listing of NFS files.
    
           **-o** directs _lsof_ to display file offset at all times.  It
                  causes the SIZE/OFF output column title to be changed to
                  OFFSET.  Note: on some UNIX dialects _lsof_ can't obtain
                  accurate or consistent file offset information from its
                  kernel data sources, sometimes just for particular kinds of
                  files (e.g., socket files.)  Consult the _lsof_ FAQ (The **FAQ**
                  section gives its location.)  for more information.
    
                  The **-o** and **-s** options are mutually exclusive; they can't
                  both be specified.  When neither is specified, _lsof_
                  displays whatever value - size or offset - is appropriate
                  and available for the type of the file.
    
           **-o** _o_   defines the number of decimal digits (_o_) to be printed
                  after the ``0t'' for a file offset before the form is
                  switched to ``0x...''.  An _o_ value of zero (unlimited)
                  directs _lsof_ to use the ``0t'' form for all offset output.
    
                  This option does NOT direct _lsof_ to display offset at all
                  times; specify **-o**(without a trailing number) to do that.
                  **-o** _o_ only specifies the number of digits after ``0t'' in
                  either mixed size and offset or offset-only output.  Thus,
                  for example, to direct _lsof_ to display offset at all times
                  with a decimal digit count of 10, use:
    
                       -o -o 10
                  or
                       -oo10
    
                  The default number of digits allowed after ``0t'' is
                  normally 8, but may have been changed by the lsof builder.
                  Consult the description of the **-o** _o_ option in the output of
                  the **-h** or **-?** option to determine the default that is in
                  effect.
    
           **-O** directs _lsof_ to bypass the strategy it uses to avoid being
                  blocked by some kernel operations - i.e., doing them in
                  forked child processes.  See the **BLOCKS AND TIMEOUTS** and
                  **AVOIDING KERNEL BLOCKS** sections for more information on
                  kernel operations that may block _lsof_.
    
                  While use of this option will reduce _lsof_ startup overhead,
                  it may also cause _lsof_ to hang when the kernel doesn't
                  respond to a function.  Use this option cautiously.
    
           **-p** _s_   excludes or selects the listing of files for the processes
                  whose optional process IDentification (PID) numbers are in
                  the comma-separated set _s_ - e.g., ``123'' or ``123,^456''.
                  (There should be no spaces in the set.)
    
                  PID numbers that begin with `^' (negation) represent
                  exclusions.
    
                  Multiple process ID numbers are joined in a single ORed set
                  before participating in AND option selection.  However, PID
                  exclusions are applied without ORing or ANDing and take
                  effect before other selection criteria are applied.
    
           **-P** inhibits the conversion of port numbers to port names for
                  network files (the mapping is commonly learned from
                  /etc/services).  Inhibiting the conversion may make _lsof_
                  run a little faster.  It is also useful when port name
                  lookup is not working properly.
    
           **-Q** ignore failed search terms. When _lsof_ is told to search for
                  users of a file, or for users of a device, or for a
                  specific PID, or for certain protocols in use by that PID,
                  and so on, _lsof_ will return an error if any of the search
                  results are empty. The **-Q** option will change this behavior
                  so that _lsof_ will instead return a successful exit code (0)
                  even if any of the search results are empty. In addition,
                  missing search terms will not be reported to stderr.
    
           **+|-r** _[t[c <N>][m<fmt>]]_
                  puts _lsof_ in repeat mode.  There _lsof_ lists open files as
                  selected by other options, delays _t_ seconds (default
                  fifteen), then repeats the listing, delaying and listing
                  repetitively until stopped by a condition defined by the
                  prefix to the option.
    
                  If the prefix is a `-', repeat mode is endless.  _Lsof_ must
                  be terminated with an interrupt or quit signal.  `c<N>' is
                  for specifying the limits of repeating; if the number of
                  iterations reaches at `<N>', _Lsof_ stops itself.
    
                  If the prefix is `+', repeat mode will end the first cycle
                  no open files are listed - and of course when _lsof_ is
                  stopped with an interrupt or quit signal.  When repeat mode
                  ends because no files are listed, the process exit code
                  will be zero if any open files were ever listed; one, if
                  none were ever listed.
    
                  _Lsof_ marks the end of each listing: if field output is in
                  progress (the **-F** , option has been specified), the default
                  marker is `m'; otherwise the default marker is
                  ``========''.  The marker is followed by a NL character.
    
                  The optional "m<fmt>" argument specifies a format for the
                  marker line.  The <fmt> characters following `m' are
                  interpreted as a format specification to the strftime(3)
                  function, when both it and the localtime(3) function are
                  available in the dialect's C library.  Consult the
                  strftime(3) documentation for what may appear in its format
                  specification.  Note that when field output is requested
                  with the **-F** option, <fmt> cannot contain the NL format,
                  ``%n''.  Note also that when <fmt> contains spaces or other
                  characters that affect the shell's interpretation of
                  arguments, <fmt> must be quoted appropriately.
    
                  Repeat mode reduces _lsof_ startup overhead, so it is more
                  efficient to use this mode than to call _lsof_ repetitively
                  from a shell script, for example.
    
                  To use repeat mode most efficiently, accompany **+|-r** with
                  specification of other _lsof_ selection options, so the
                  amount of kernel memory access _lsof_ does will be kept to a
                  minimum.  Options that filter at the process level - e.g.,
                  **-c** , **-g** , **-p** , **-u** - are the most efficient selectors.
    
                  Repeat mode is useful when coupled with field output (see
                  the **-F** , option description) and a supervising _awk_ or _Perl_
                  script, or a C program.
    
           **-R** directs lsof to list the Parent Process IDentification
                  number in the PPID column.
    
           **-s** _[p:s]_
                  **s** alone directs _lsof_ to display file size at all times.  It
                  causes the SIZE/OFF output column title to be changed to
                  SIZE.  If the file does not have a size, nothing is
                  displayed.
    
                  The optional **-s** _p:s_ form is available only for selected
                  dialects, and only when the **-h** or **-?** help output lists it.
    
                  When the optional form is available, the **s** may be followed
                  by a protocol name (_p_), either TCP or UDP, a colon (`:')
                  and a comma-separated protocol state name list, the option
                  causes open TCP and UDP files to be excluded if their state
                  name(s) are in the list (_s_) preceded by a `^'; or included
                  if their name(s) are not preceded by a `^'.
    
                  Dialects that support this option may support only one
                  protocol.  When an unsupported protocol is specified, a
                  message will be displayed indicating state names for the
                  protocol are unavailable.
    
                  When an inclusion list is defined, only network files with
                  state names in the list will be present in the _lsof_ output.
                  Thus, specifying one state name means that only network
                  files with that lone state name will be listed.
    
                  Case is unimportant in the protocol or state names, but
                  there may be no spaces and the colon (`:') separating the
                  protocol name (_p_) and the state name list (_s_) is required.
    
                  If only TCP and UDP files are to be listed, as controlled
                  by the specified exclusions and inclusions, the **-i** option
                  must be specified, too.  If only a single protocol's files
                  are to be listed, add its name as an argument to the **-i**
                  option.
    
                  For example, to list only network files with TCP state
                  LISTEN, use:
    
                       -iTCP -sTCP:LISTEN
    
                  Or, for example, to list network files with all UDP states
                  except Idle, use:
    
                       -iUDP -sUDP:^Idle
    
                  State names vary with UNIX dialects, so it's not possible
                  to provide a complete list.  Some common TCP state names
                  are: CLOSED, IDLE, BOUND, LISTEN, ESTABLISHED, SYN_SENT,
                  SYN_RCDV, ESTABLISHED, CLOSE_WAIT, FIN_WAIT1, CLOSING,
                  LAST_ACK, FIN_WAIT_2, and TIME_WAIT.  Two common UDP state
                  names are Unbound and Idle.
    
                  See the _lsof_ FAQ (The **FAQ** section gives its location.)  for
                  more information on how to use protocol state exclusion and
                  inclusion, including examples.
    
                  The **-o**(without a following decimal digit count) and **-s**
                  option (without a following protocol and state name list)
                  are mutually exclusive; they can't both be specified.  When
                  neither is specified, _lsof_ displays whatever value - size
                  or offset - is appropriate and available for the type of
                  file.
    
                  Since some types of files don't have true sizes - sockets,
                  FIFOs, pipes, etc. - lsof displays for their sizes the
                  content amounts in their associated kernel buffers, if
                  possible.
    
           **-S** _[t]_ specifies an optional time-out seconds value for kernel
                  functions - lstat(2), readlink(2), and stat(2) - that might
                  otherwise deadlock.  The minimum for _t_ is two; the default,
                  fifteen; when no value is specified, the default is used.
    
                  See the **BLOCKS AND TIMEOUTS** section for more information.
    
           **-T** _[t]_ controls the reporting of some TCP/TPI information, also
                  reported by **netstat**(1), following the network addresses.
                  In normal output the information appears in parentheses,
                  each item except TCP or TPI state name identified by a
                  keyword, followed by `=', separated from others by a single
                  space:
    
                       <TCP or TPI state name>
                       QR=<read queue length>
                       QS=<send queue length>
                       SO=<socket options and values>
                       SS=<socket states>
                       TF=<TCP flags and values>
                       WR=<window read length>
                       WW=<window write length>
    
                  Not all values are reported for all UNIX dialects.  Items
                  values (when available) are reported after the item name
                  and '='.
    
                  When the field output mode is in effect (See **OUTPUT FOR**
                  **OTHER PROGRAMS**.)  each item appears as a field with a `T'
                  leading character.
    
                  **-T** with no following key characters disables TCP/TPI
                  information reporting.
    
                  **-T** with following characters selects the reporting of
                  specific TCP/TPI information:
    
                       **f** selects reporting of socket options,
                            states and values, and TCP flags and
                            values.
                       **q** selects queue length reporting.
                       **s** selects connection state reporting.
                       **w** selects window size reporting.
    
                  Not all selections are enabled for some UNIX dialects.
                  State may be selected for all dialects and is reported by
                  default.  The **-h** or **-?** help output for the **-T** option will
                  show what selections may be used with the UNIX dialect.
    
                  When **-T** is used to select information - i.e., it is
                  followed by one or more selection characters - the
                  displaying of state is disabled by default, and it must be
                  explicitly selected again in the characters following **-T**.
                  (In effect, then, the default is equivalent to **-Ts**.)  For
                  example, if queue lengths and state are desired, use **-Tqs**.
    
                  Socket options, socket states, some socket values, TCP
                  flags and one TCP value may be reported (when available in
                  the UNIX dialect) in the form of the names that commonly
                  appear after SO_, so_, SS_, TCP_  and TF_ in the dialect's
                  header files - most often <sys/socket.h>, <sys/socketvar.h>
                  and <netinet/tcp_var.h>.  Consult those header files for
                  the meaning of the flags, options, states and values.
    
                  ``SO='' precedes socket options and values; ``SS='', socket
                  states; and ``TF='', TCP flags and values.
    
                  If a flag or option has a value, the value will follow an
                  '=' and the name -- e.g., ``SO=LINGER=5'', ``SO=QLIM=5'',
                  ``TF=MSS=512''.  The following seven values may be
                  reported:
    
                       Name
                       Reported  Description (Common Symbol)
    
                       KEEPALIVE keep alive time (SO_KEEPALIVE)
                       LINGER    linger time (SO_LINGER)
                       MSS       maximum segment size (TCP_MAXSEG)
                       PQLEN          partial listen queue connections
                       QLEN      established listen queue connections
                       QLIM      established listen queue limit
                       RCVBUF    receive buffer length (SO_RCVBUF)
                       SNDBUF    send buffer length (SO_SNDBUF)
    
                  Details on what socket options and values, socket states,
                  and TCP flags and values may be displayed for particular
                  UNIX dialects may be found in the answer to the ``Why
                  doesn't lsof report socket options, socket states, and TCP
                  flags and values for my dialect?'' and ``Why doesn't lsof
                  report the partial listen queue connection count for my
                  dialect?''  questions in the _lsof_ FAQ (The **FAQ** section
                  gives its location.)  On Linux this option also prints the
                  state of UNIX domain sockets.
    
           **-t** produce terse output comprising only process identifiers
                  (without a header), so that it is easy to use
                  programmatically. e.g.
    
                       # reload anything using old SSL
                       lsof -t /lib/*/libssl.so.* | xargs -r kill -HUP
    
                       # get list of processes and then iterate over them (Bash only)
                       mapfile -t pids < <(
                           lsof -wt /var/log/your.log
                       )
                       for pid in "${pids[@]}" ; do
                           your_command -p "$pid"
                       done
    
                  The **-t** option implies the **-w** option.
    
           **-u** _s_   selects the listing of files for the user whose login names
                  or user ID numbers are in the comma-separated set _s_ - e.g.,
                  ``abe'', or ``548,root''.  (There should be no spaces in
                  the set.)
    
                  Multiple login names or user ID numbers are joined in a
                  single ORed set before participating in AND option
                  selection.
    
                  If a login name or user ID is preceded by a `^', it becomes
                  a negation - i.e., files of processes owned by the login
                  name or user ID will never be listed.  A negated login name
                  or user ID selection is neither ANDed nor ORed with other
                  selections; it is applied before all other selections and
                  absolutely excludes the listing of the files of the
                  process.  For example, to direct _lsof_ to exclude the
                  listing of files belonging to root processes, specify
                  ``-u^root'' or ``-u^0''.
    
           **-U** selects the listing of UNIX domain socket files.
    
           **-v** selects the listing of _lsof_ version information, including:
                  revision number; when the _lsof_ binary was constructed; who
                  constructed the binary and where; the name of the compiler
                  used to construct the _lsof binary;_ the version number of
                  the compiler when readily available; the compiler and
                  loader flags used to construct the _lsof_ binary; and system
                  information, typically the output of _uname_ 's **-a** option.
    
           **-V** directs _lsof_ to indicate the items it was asked to list and
                  failed to find - command names, file names, Internet
                  addresses or files, login names, NFS files, PIDs, PGIDs,
                  and UIDs.
    
                  When other options are ANDed to search options, or
                  compile-time options restrict the listing of some files,
                  _lsof_ may not report that it failed to find a search item
                  when an ANDed option or compile-time option prevents the
                  listing of the open file containing the located search
                  item.
    
                  For example, ``lsof -V -iTCP@foobar -a -d 999'' may not
                  report a failure to locate open files at ``TCP@foobar'' and
                  may not list any, if none have a file descriptor number of
                  999.  A similar situation arises when HASSECURITY and
                  HASNOSOCKSECURITY are defined at compile time and they
                  prevent the listing of open files.
    
           **+|-w** Enables (**+**) or disables (**-**) the suppression of warning
                  messages.
    
                  The _lsof_ builder may choose to have warning messages
                  disabled or enabled by default.  The default warning
                  message state is indicated in the output of the **-h** or **-?**
                  option.  Disabling warning messages when they are already
                  disabled or enabling them when already enabled is
                  acceptable.
    
                  The **-t** option implies the **-w** option.
    
           **-x** _[fl]_
                  may accompany the **+d** and **+D** options to direct their
                  processing to cross over symbolic links and|or file system
                  mount points encountered when scanning the directory (**+d**)
                  or directory tree (**+D**).
    
                  If **-x** is specified by itself without a following parameter,
                  cross-over processing of both symbolic links and file
                  system mount points is enabled.  Note that when **-x** is
                  specified without a parameter, the next argument must begin
                  with '-' or '+'.
    
                  The optional 'f' parameter enables file system mount point
                  cross-over processing; 'l', symbolic link cross-over
                  processing.
    
                  The **-x** option may not be supplied without also supplying a
                  **+d** or **+D** option.
    
           **-X** This is a dialect-specific option.
    
               AIX:
                    This IBM AIX RISC/System 6000 option requests the
                    reporting of executed text file and shared library
                    references.
    
                    **WARNING:** because this option uses the kernel readx()
                    function, its use on a busy AIX system might cause an
                    application process to hang so completely that it can
                    neither be killed nor stopped.  I have never seen this
                    happen or had a report of its happening, but I think
                    there is a remote possibility it could happen.
    
                    By default use of readx() is disabled.  On AIX 5L and
                    above _lsof_ may need setuid-root permission to perform the
                    actions this option requests.
    
                    The _lsof_ builder may specify that the **-X** option be
                    restricted to processes whose real UID is root.  If that
                    has been done, the **-X** option will not appear in the **-h** or
                    **-?** help output unless the real UID of the _lsof_ process
                    is root.  The default _lsof_ distribution allows any UID to
                    specify **-X,** so by default it will appear in the help
                    output.
    
                    When AIX readx() use is disabled, _lsof_ may not be able to
                    report information for all text and loader file
                    references, but it may also avoid exacerbating an AIX
                    kernel directory search kernel error, known as the Stale
                    Segment ID bug.
    
                    The readx() function, used by _lsof_ or any other program
                    to access some sections of kernel virtual memory, can
                    trigger the Stale Segment ID bug.  It can cause the
                    kernel's dir_search() function to believe erroneously
                    that part of an in-memory copy of a file system directory
                    has been zeroed.  Another application process, distinct
                    from _lsof_ , asking the kernel to search the directory -
                    e.g., by using _open_(2) - can cause dir_search() to loop
                    forever, thus hanging the application process.
    
                    Consult the _lsof_ FAQ (The **FAQ** section gives its
                    location.)  and the _00README_ file of the _lsof_
                    distribution for a more complete description of the Stale
                    Segment ID bug, its APAR, and methods for defining
                    readx() use when compiling _lsof_.
    
               Linux:
                    This Linux option requests that _lsof_ skip the reporting
                    of information on all open TCP, UDP and UDPLITE IPv4 and
                    IPv6 files.
    
                    This Linux option is most useful when the system has an
                    extremely large number of open TCP, UDP and UDPLITE
                    files, the processing of whose information in the
                    _/proc/net/tcp*_ and _/proc/net/udp*_ files would take _lsof_ a
                    long time, and whose reporting is not of interest.
    
                    Use this option with care and only when you are sure that
                    the information you want _lsof_ to display isn't associated
                    with open TCP, UDP or UDPLITE socket files.
    
               Solaris 10 and above:
                    This Solaris 10 and above option requests the reporting
                    of cached paths for files that have been deleted - i.e.,
                    removed with rm(1) or unlink(2).
    
                    The cached path is followed by the string `` (deleted)''
                    to indicate that the path by which the file was opened
                    has been deleted.
    
                    Because intervening changes made to the path - i.e.,
                    renames with mv(1) or rename(2) - are not recorded in the
                    cached path, what _lsof_ reports is only the path by which
                    the file was opened, not its possibly different final
                    path.
    
           **-z** _[z]_   specifies how Solaris 10 and higher zone information is
                    to be handled.
    
                    Without a following argument - e.g., NO _z_ - the option
                    specifies that zone names are to be listed in the ZONE
                    output column.
    
                    The **-z** option may be followed by a zone name, **z** _._  That
                    causes lsof to list only open files for processes in that
                    zone.  Multiple **-z** _z_ option and argument pairs may be
                    specified to form a list of named zones.  Any open file
                    of any process in any of the zones will be listed,
                    subject to other conditions specified by other options
                    and arguments.
    
           **-Z** _[Z]_   specifies how SELinux security contexts are to be
                    handled.  It and 'Z' field output character support are
                    inhibited when SELinux is disabled in the running Linux
                    kernel.  See **OUTPUT FOR OTHER PROGRAMS** for more
                    information on the 'Z' field output character.
    
                    Without a following argument - e.g., NO _Z_ - the option
                    specifies that security contexts are to be listed in the
                    SECURITY-CONTEXT output column.
    
                    The **-Z** option may be followed by a wildcard security
                    context name, **Z** _._  That causes lsof to list only open
                    files for processes in that security context.  Multiple
                    **-Z** _Z_ option and argument pairs may be specified to form a
                    list of security contexts.  Any open file of any process
                    in any of the security contexts will be listed, subject
                    to other conditions specified by other options and
                    arguments.  Note that _Z_ can be A:B:C or *:B:C or A:B:* or
                    *:*:C to match against the A:B:C context.
    
           **--** The double minus sign option is a marker that signals the
                    end of the keyed options.  It may be used, for example,
                    when the first file name begins with a minus sign.  It
                    may also be used when the absence of a value for the last
                    keyed option must be signified by the presence of a minus
                    sign in the following option and before the start of the
                    file names.
    
           _names_    These are path names of specific files to list.  Symbolic
                    links are resolved before use.  The first name may be
                    separated from the preceding options with the ``--''
                    option.
    
                    If a _name_ is the mounted-on directory of a file system or
                    the device of the file system, _lsof_ will list all the
                    files open on the file system.  To be considered a file
                    system, the _name_ must match a mounted-on directory name
                    in mount(8) output, or match the name of a block device
                    associated with a mounted-on directory name.  The **+|-f**
                    option may be used to force _lsof_ to consider a _name_ a
                    file system identifier (**+f**) or a simple file (**-f**).
    
                    If _name_ is a path to a directory that is not the
                    mounted-on directory name of a file system, it is treated
                    just as a regular file is treated - i.e., its listing is
                    restricted to processes that have it open as a file or as
                    a process-specific directory, such as the root or current
                    working directory.  To request that _lsof_ look for open
                    files inside a directory name, use the **+d** _s_ and **+D** _D_
                    options.
    
                    If a _name_ is the base name of a family of multiplexed
                    files - e.g, AIX's _/dev/pt[cs]_ - _lsof_ will list all the
                    associated multiplexed files on the device that are open
                    - e.g., _/dev/pt[cs]/1_ , _/dev/pt[cs]/2_ , etc.
    
                    If a _name_ is a UNIX domain socket name, _lsof_ will usually
                    search for it by the characters of the name alone -
                    exactly as it is specified and is recorded in the kernel
                    socket structure.  (See the next paragraph for an
                    exception to that rule for Linux.)  Specifying a relative
                    path - e.g., _./file_ - in place of the file's absolute
                    path - e.g., _/tmp/file_ - won't work because _lsof_ must
                    match the characters you specify with what it finds in
                    the kernel UNIX domain socket structures.
    
                    If a _name_ is a Linux UNIX domain socket name, in one case
                    _lsof_ is able to search for it by its device and inode
                    number, allowing _name_ to be a relative path.  The case
                    requires that the absolute path -- i.e., one beginning
                    with a slash ('/') be used by the process that created
                    the socket, and hence be stored in the _/proc/net/unix_
                    file; and it requires that _lsof_ be able to obtain the
                    device and node numbers of both the absolute path in
                    _/proc/net/unix_ and _name_ via successful stat(2) system
                    calls.  When those conditions are met, _lsof_ will be able
                    to search for the UNIX domain socket when some path to it
                    is is specified in _name_.  Thus, for example, if the path
                    is _/dev/log_ , and an _lsof_ search is initiated when the
                    working directory is _/dev_ , then _name_ could be _./log_.
    
                    If a _name_ is none of the above, _lsof_ will list any open
                    files whose device and inode match that of the specified
                    path _name_.
    
                    If you have also specified the **-b** option, the only _names_
                    you may safely specify are file systems for which your
                    mount table supplies alternate device numbers.  See the
                    **AVOIDING KERNEL BLOCKS** and **ALTERNATE DEVICE NUMBERS**
                    sections for more information.
    
                    Multiple file names are joined in a single ORed set
                    before participating in AND option selection.
    


## AFS



           _Lsof_ supports the recognition of AFS files for these dialects (and
           AFS versions):
    
                AIX 4.1.4 (AFS 3.4a)
                HP-UX 9.0.5 (AFS 3.4a)
                Linux 1.2.13 (AFS 3.3)
                Solaris 2.[56] (AFS 3.4a)
    
           It may recognize AFS files on other versions of these dialects,
           but has not been tested there.  Depending on how AFS is
           implemented, _lsof_ may recognize AFS files in other dialects, or
           may have difficulties recognizing AFS files in the supported
           dialects.
    
           _Lsof_ may have trouble identifying all aspects of AFS files in
           supported dialects when AFS kernel support is implemented via
           dynamic modules whose addresses do not appear in the kernel's
           variable name list.  In that case, _lsof_ may have to guess at the
           identity of AFS files, and might not be able to obtain volume
           information from the kernel that is needed for calculating AFS
           volume node numbers.  When _lsof_ can't compute volume node numbers,
           it reports blank in the NODE column.
    
           The **-A** _A_ option is available in some dialect implementations of
           _lsof_ for specifying the name list file where dynamic module kernel
           addresses may be found.  When this option is available, it will be
           listed in the _lsof_ help output, presented in response to the **-h** or
           **-?**
    
           See the _lsof_ FAQ (The **FAQ** section gives its location.)  for more
           information about dynamic modules, their symbols, and how they
           affect _lsof_ options.
    
           Because AFS path lookups don't seem to participate in the kernel's
           name cache operations, _lsof_ can't identify path name components
           for AFS files.
    


## SECURITY



           _Lsof_ has three features that may cause security concerns.  First,
           its default compilation mode allows anyone to list all open files
           with it.  Second, by default it creates a user-readable and
           user-writable device cache file in the home directory of the real
           user ID that executes _lsof_.  (The list-all-open-files and device
           cache features may be disabled when _lsof_ is compiled.)  Third, its
           **-k** and **-m** options name alternate kernel name list or memory files.
    
           Restricting the listing of all open files is controlled by the
           compile-time HASSECURITY and HASNOSOCKSECURITY options.  When
           HASSECURITY is defined, _lsof_ will allow only the root user to list
           all open files.  The non-root user may list only open files of
           processes with the same user IDentification number as the real
           user ID number of the _lsof_ process (the one that its user logged
           on with).
    
           However, if HASSECURITY and HASNOSOCKSECURITY are both defined,
           anyone may list open socket files, provided they are selected with
           the **-i** option.
    
           When HASSECURITY is not defined, anyone may list all open files.
    
           Help output, presented in response to the **-h** or **-?** option, gives
           the status of the HASSECURITY and HASNOSOCKSECURITY definitions.
    
           See the **Security** section of the _00README_ file of the _lsof_
           distribution for information on building _lsof_ with the HASSECURITY
           and HASNOSOCKSECURITY options enabled.
    
           Creation and use of a user-readable and user-writable device cache
           file is controlled by the compile-time HASDCACHE option.  See the
           **DEVICE CACHE FILE** section and the sections that follow it for
           details on how its path is formed.  For security considerations it
           is important to note that in the default _lsof_ distribution, if the
           real user ID under which _lsof_ is executed is root, the device
           cache file will be written in root's home directory - e.g., _/_ or
           _/root_.  When HASDCACHE is not defined, _lsof_ does not write or
           attempt to read a device cache file.
    
           When HASDCACHE is defined, the _lsof_ help output, presented in
           response to the **-h** , **-D?** , or **-?** options, will provide device cache
           file handling information.  When HASDCACHE is not defined, the **-h**
           or **-?** output will have no **-D** option description.
    
           Before you decide to disable the device cache file feature -
           enabling it improves the performance of _lsof_ by reducing the
           startup overhead of examining all the nodes in _/dev_ (or _/devices_)
           - read the discussion of it in the _00DCACHE_ file of the _lsof_
           distribution and the _lsof_ FAQ (The **FAQ** section gives its
           location.)
    
           WHEN IN DOUBT, YOU CAN TEMPORARILY DISABLE THE USE OF THE DEVICE
           CACHE FILE WITH THE **-Di** OPTION.
    
           When _lsof_ user declares alternate kernel name list or memory files
           with the **-k** and **-m** options, _lsof_ checks the user's authority to
           read them with access(2).  This is intended to prevent whatever
           special power _lsof's_ modes might confer on it from letting it read
           files not normally accessible via the authority of the real user
           ID.
    


## OUTPUT



           This section describes the information _lsof_ lists for each open
           file.  See the **OUTPUT FOR OTHER PROGRAMS** section for additional
           information on output that can be processed by another program.
    
           _Lsof_ only outputs printable (declared so by isprint(3)) 8 bit
           characters.  Non-printable characters are printed in one of three
           forms: the C ``\[bfrnt]'' form; the control character `^' form
           (e.g., ``^@''); or hexadecimal leading ``\x'' form (e.g.,
           ``\xab'').  Space is non-printable in the COMMAND column
           (``\x20'') and printable elsewhere.
    
           For some dialects - if HASSETLOCALE is defined in the dialect's
           machine.h header file - _lsof_ will print the extended 8 bit
           characters of a language locale.  The _lsof_ process must be
           supplied a language locale environment variable (e.g., LANG) whose
           value represents a known language locale in which the extended
           characters are considered printable by isprint(3).  Otherwise _lsof_
           considers the extended characters non-printable and prints them
           according to its rules for non-printable characters, stated above.
           Consult your dialect's setlocale(3) man page for the names of
           other environment variables that may be used in place of LANG -
           e.g., LC_ALL, LC_CTYPE, etc.
    
           _Lsof's_ language locale support for a dialect also covers wide
           characters - e.g., UTF-8 - when HASSETLOCALE and HASWIDECHAR are
           defined in the dialect's machine.h header file, and when a
           suitable language locale has been defined in the appropriate
           environment variable for the _lsof_ process.  Wide characters are
           printable under those conditions if iswprint(3) reports them to
           be.  If HASSETLOCALE, HASWIDECHAR and a suitable language locale
           aren't defined, or if iswprint(3) reports wide characters that
           aren't printable, _lsof_ considers the wide characters non-printable
           and prints each of their 8 bits according to its rules for
           non-printable characters, stated above.
    
           Consult the answers to the "Language locale support" questions in
           the lsof FAQ (The **FAQ** section gives its location.) for more
           information.
    
           _Lsof_ dynamically sizes the output columns each time it runs,
           guaranteeing that each column is a minimum size.  It also
           guarantees that each column is separated from its predecessor by
           at least one space.
    
           COMMAND
                  contains the first nine characters of the name of the UNIX
                  command associated with the process.  If a non-zero _w_ value
                  is specified to the **+c** _w_ option, the column contains the
                  first _w_ characters of the name of the UNIX command
                  associated with the process up to the limit of characters
                  supplied to _lsof_ by the UNIX dialect.  (See the description
                  of the **+c** _w_ command or the _lsof_ FAQ for more information.
                  The **FAQ** section gives its location.)
    
                  If _w_ is less than the length of the column title,
                  ``COMMAND'', it will be raised to that length.
    
                  If a zero _w_ value is specified to the **+c** _w_ option, the
                  column contains all the characters of the name of the UNIX
                  command associated with the process.
    
                  All command name characters maintained by the kernel in its
                  structures are displayed in field output when the command
                  name descriptor (`c') is specified.  See the **OUTPUT FOR**
                  **OTHER COMMANDS** section for information on selecting field
                  output and the associated command name descriptor.
    
           PID    is the Process IDentification number of the process.
    
           TID    is the task (thread) IDentification number, if task
                  (thread) reporting is supported by the dialect and a task
                  (thread) is being listed.  (If help output - i.e., the
                  output of the **-h** or **-?** options - shows this option, then
                  task (thread) reporting is supported by the dialect.)
    
                  A blank TID column in Linux indicates a process - i.e., a
                  non-task.
    
           TASKCMD
                  is the task command name.  Generally this will be the same
                  as the process named in the COMMAND column, but some task
                  implementations (e.g., Linux) permit a task to change its
                  command name.
    
                  The TASKCMD column width is subject to the same size
                  limitation as the COMMAND column.
    
           ZONE   is the Solaris 10 and higher zone name.  This column must
                  be selected with the **-z** option.
    
           SECURITY-CONTEXT
                  is the SELinux security context.  This column must be
                  selected with the **-Z** option.  Note that the **-Z** option is
                  inhibited when SELinux is disabled in the running Linux
                  kernel.
    
           PPID   is the Parent Process IDentification number of the process.
                  It is only displayed when the **-R** option has been specified.
    
           PGID   is the process group IDentification number associated with
                  the process.  It is only displayed when the **-g** option has
                  been specified.
    
           USER   is the user ID number or login name of the user to whom the
                  process belongs, usually the same as reported by ps(1).
                  However, on Linux USER is the user ID number or login that
                  owns the directory in /proc where _lsof_ finds information
                  about the process.  Usually that is the same value reported
                  by ps(1), but may differ when the process has changed its
                  effective user ID.  (See the **-l** option description for
                  information on when a user ID number or login name is
                  displayed.)
    
           FD     is the File Descriptor number of the file or:
    
                       **cwd** current working directory;
                       **L** _nn_  library references (AIX);
                       **ctty** character tty;
                       **DEL** deleted file;
                       **err** FD information error (see NAME column);
                       **fp.** Fileport (Darwin);
                       **jld** jail directory (FreeBSD);
                       **ltx** shared library text (code and data);
                       **M** _xx_  hex memory-mapped type number xx.
                       **m86** DOS Merge mapped file;
                       **mem** memory-mapped file;
                       **mmap** memory-mapped device;
                       **NOFD** for a Linux /proc/<PID>/fd directory that can't be opened --
                            the directory path appears in the NAME column, followed by an error
                            message;
                       **pd** parent directory;
                       **R** _nn_  unknown pregion number (HP-UX);
                       **rtd** root directory;
                       **twd** per task current working directory;
                       **txt** program text (code and data);
                       **v86** VP/ix mapped file;
    
                  FD is followed by one of these characters, describing the
                  mode under which the file is open:
    
                       **r** for read access;
                       **w** for write access;
                       **u** for read and write access;
                       space if mode unknown and no lock
                            character follows;
                       `-' if mode unknown and lock
                            character follows.
    
                  The mode character is followed by one of these lock
                  characters, describing the type of lock applied to the
                  file:
    
                       **N** for a Solaris NFS lock of unknown type;
                       **r** for read lock on part of the file;
                       **R** for a read lock on the entire file;
                       **w** for a write lock on part of the file;
                       **W** for a write lock on the entire file;
                       **u** for a read and write lock of any length;
                       **U** for a lock of unknown type;
                       **x** for an SCO OpenServer Xenix lock on part of the
                  file;
                       **X** for an SCO OpenServer Xenix lock on the entire file;
                       space if there is no lock.
    
                  See the **LOCKS** section for more information on the lock
                  information character.
    
                  The FD column contents constitutes a single field for
                  parsing in post-processing scripts. FD numbers larger than
                  9999 are abbreviated to a ``*'' followed by the last three
                  digits. E.g., 10001 appears as ``*001''
    
           TYPE   is the type of the node associated with the file - e.g.,
                  VDIR, VREG, etc.
    
                  or ``ax25'' for a Linux AX.25 socket;
    
                  or ``a_inode'' for anonymous inode;
    
                  or ``icmp'' for an ICMP socket;
    
                  or ``inet'' for an Internet domain socket;
    
                  or ``ipx'' for an IPX socket;
    
                  or ``key'' for an internal key management socket;
    
                  or ``lla'' for a HP-UX link level access file;
    
                  or ``ndrv'' for a net driver socket;
    
                  or ``netlink'' for a netlink socket;
    
                  or ``pack'' for a packet socket;
    
                  or ``ppp'' for a PPP socket;
    
                  or ``raw'' for a raw socket;
    
                  or ``raw6'' for a raw IPv6 socket;
    
                  or ``rte'' for an AF_ROUTE socket;
    
                  or ``sock'' for a socket of unknown domain;
    
                  or ``systm'' for a system socket;
    
                  or ``unix'' for a UNIX domain socket;
    
                  or ``x.25'' for an HP-UX x.25 socket;
    
                  or ``ATALK'' for an AppleTalk socket;
    
                  or ``BLK'' for a block special file;
    
                  or ``CHR'' for a character special file;
    
                  or ``DEL'' for a Linux map file that has been deleted;
    
                  or ``DIR'' for a directory;
    
                  or ``DOOR'' for a VDOOR file;
    
                  or ``EVENTFD'' for an eventfd;
    
                  or ``FIFO'' for a FIFO special file;
    
                  or ``FSEVENTS'' for fsevents;
    
                  or ``IPv4'' for an IPv4 socket;
    
                  or ``IPv6'' for an open IPv6 network file - even if its
                  address is IPv4, mapped in an IPv6 address;
    
                  or ``KQUEUE'' for a BSD style kernel event queue file;
    
                  or ``LINK'' for a symbolic link file;
    
                  or ``MPB'' for a multiplexed block file;
    
                  or ``MPC'' for a multiplexed character file;
    
                  or ``PAS'' for a _/proc/as_ file;
    
                  or ``PAXV'' for a _/proc/auxv_ file;
    
                  or ``PCRE'' for a _/proc/cred_ file;
    
                  or ``PCTL'' for a _/proc_ control file;
    
                  or ``PCUR'' for the current _/proc_ process;
    
                  or ``PCWD'' for a _/proc_ current working directory;
    
                  or ``PDIR'' for a _/proc_ directory;
    
                  or ``PETY'' for a _/proc_ executable type (_etype_);
    
                  or ``PFD'' for a _/proc_ file descriptor;
    
                  or ``PFDR'' for a _/proc_ file descriptor directory;
    
                  or ``PFIL'' for an executable _/proc_ file;
    
                  or ``PFPR'' for a _/proc_ FP register set;
    
                  or ``PGD'' for a _/proc/pagedata_ file;
    
                  or ``PGID'' for a _/proc_ group notifier file;
    
                  or ``PIPE'' for pipes;
    
                  or ``PLC'' for a _/proc/lwpctl_ file;
    
                  or ``PLDR'' for a _/proc/lpw_ directory;
    
                  or ``PLDT'' for a _/proc/ldt_ file;
    
                  or ``PLPI'' for a _/proc/lpsinfo_ file;
    
                  or ``PLST'' for a _/proc/lstatus_ file;
    
                  or ``PLU'' for a _/proc/lusage_ file;
    
                  or ``PLWG'' for a _/proc/gwindows_ file;
    
                  or ``PLWI'' for a _/proc/lwpsinfo_ file;
    
                  or ``PLWS'' for a _/proc/lwpstatus_ file;
    
                  or ``PLWU'' for a _/proc/lwpusage_ file;
    
                  or ``PLWX'' for a _/proc/xregs_ file;
    
                  or ``PMAP'' for a _/proc_ map file (_map_);
    
                  or ``PMPS'' for a _/proc/maps_ file;
    
                  or ``PMEM'' for a _/proc_ memory image file;
    
                  or ``PNTF'' for a _/proc_ process notifier file;
    
                  or ``POBJ'' for a _/proc/object_ file;
    
                  or ``PODR'' for a _/proc/object_ directory;
    
                  or ``POLP'' for an old format _/proc_ light weight process
                  file;
    
                  or ``POPF'' for an old format _/proc_ PID file;
    
                  or ``POPG'' for an old format _/proc_ page data file;
    
                  or ``PORT'' for a SYSV named pipe;
    
                  or ``PREG'' for a _/proc_ register file;
    
                  or ``PRMP'' for a _/proc/rmap_ file;
    
                  or ``PROCDSC'' for a processor descriptor;
    
                  or ``PRTD'' for a _/proc_ root directory;
    
                  or ``PSGA'' for a _/proc/sigact_ file;
    
                  or ``PSIN'' for a _/proc/psinfo_ file;
    
                  or ``PSTA'' for a _/proc_ status file;
    
                  or ``PSXMQ'' for a POSIX message queue file;
    
                  or ``PSXSEM'' for a POSIX semaphore file;
    
                  or ``PSXSHM'' for a POSIX shared memory file;
    
                  or ``PTS'' for a _/dev/pts_ file;
    
                  or ``PUSG'' for a _/proc/usage_ file;
    
                  or ``PW'' for a _/proc/watch_ file;
    
                  or ``PXMP'' for a _/proc/xmap_ file;
    
                  or ``REG'' for a regular file;
    
                  or ``SHM'' for a shared memory file;
    
                  or ``SMT'' for a shared memory transport file;
    
                  or ``STR'' for streams;
    
                  or ``STSO'' for a stream socket;
    
                  or ``UNKN'' for an unknown file;
    
                  or ``UNKNcwd'' for unknown current working directory;
    
                  or ``UNKNdel'' for unknown deleted file;
    
                  or ``UNKNfd'' for unknown file descriptor;
    
                  or ``UNKNmem'' for unknown memory-mapped file;
    
                  or ``UNKNrtd'' for unknown root directory;
    
                  or ``UNKNtxt'' for unknown program text;
    
                  or ``UNNM'' for an unnamed type file;
    
                  or ``XNAM'' for an OpenServer Xenix special file of unknown
                  type;
    
                  or ``XSEM'' for an OpenServer Xenix semaphore file;
    
                  or ``XSD'' for an OpenServer Xenix shared data file;
    
                  or ``UNSP'' for an unsupported file;
    
                  or the four type number octets if the corresponding name
                  isn't known.
    
           FILE-ADDR
                  contains the kernel file structure address when **f** has been
                  specified to **+f** ;
    
           FCT    contains the file reference count from the kernel file
                  structure when **c** has been specified to **+f** ;
    
           FILE-FLAG
                  when **g** or **G** has been specified to **+f** , this field contains
                  the contents of the f_flag[s] member of the kernel file
                  structure and the kernel's per-process open file flags (if
                  available); `G' causes them to be displayed in hexadecimal;
                  `g', as short-hand names; two lists may be displayed with
                  entries separated by commas, the lists separated by a
                  semicolon (`;'); the first list may contain short-hand
                  names for f_flag[s] values from the following table:
    
                       AIO       asynchronous I/O (e.g., FAIO)
                       AP        append
                       ASYN      asynchronous I/O (e.g., FASYNC)
                       BAS       block, test, and set in use
                       BKIU      block if in use
                       BL        use block offsets
                       BSK       block seek
                       CA        copy avoid
                       CIO       concurrent I/O
                       CLON      clone
                       CLRD      CL read
                       CR        create
                       DF        defer
                       DFI       defer IND
                       DFLU      data flush
                       DIR       direct
                       DLY       delay
                       DOCL      do clone
                       DSYN      data-only integrity
                       DTY       must be a directory
                       EVO       event only
                       EX        open for exec
                       EXCL      exclusive open
                       FSYN      synchronous writes
                       GCDF      defer during unp_gc() (AIX)
                       GCMK      mark during unp_gc() (AIX)
                       GTTY      accessed via /dev/tty
                       HUP       HUP in progress
                       KERN      kernel
                       KIOC      kernel-issued ioctl
                       LCK       has lock
                       LG        large file
                       MBLK      stream message block
                       MK        mark
                       MNT       mount
                       MSYN      multiplex synchronization
                       NATM      don't update atime
                       NB        non-blocking I/O
                       NBDR      no BDRM check
                       NBIO      SYSV non-blocking I/O
                       NBF       n-buffering in effect
                       NC        no cache
                       ND        no delay
                       NDSY      no data synchronization
                       NET       network
                       NFLK      don't follow links
                       NMFS      NM file system
                       NOTO      disable background stop
                       NSH       no share
                       NTTY      no controlling TTY
                       OLRM      OLR mirror
                       PAIO      POSIX asynchronous I/O
                       PATH      path
                       PP        POSIX pipe
                       R         read
                       RC        file and record locking cache
                       REV       revoked
                       RSH       shared read
                       RSYN      read synchronization
                       RW        read and write access
                       SL        shared lock
                       SNAP      cooked snapshot
                       SOCK      socket
                       SQSH      Sequent shared set on open
                       SQSV      Sequent SVM set on open
                       SQR       Sequent set repair on open
                       SQS1      Sequent full shared open
                       SQS2      Sequent partial shared open
                       STPI      stop I/O
                       SWR       synchronous read
                       SYN       file integrity while writing
                       TCPM      avoid TCP collision
                       TMPF      temporary file
                       TR        truncate
                       W         write
                       WKUP      parallel I/O synchronization
                       WTG       parallel I/O synchronization
                       VH        vhangup pending
                       VTXT      virtual text
                       XL        exclusive lock
    
                  this list of names was derived from F* #define's in dialect
                  header files <fcntl.h>, <linux</fs.h>, <sys/fcntl.c>,
                  <sys/fcntlcom.h>, and <sys/file.h>; see the common.h header
                  file for a list showing the correspondence between the
                  above short-hand names and the header file definitions;
    
                  the second list (after the semicolon) may contain short-
                  hand names for kernel per-process open file flags from this
                  table:
    
                       ALLC      allocated
                       BR        the file has been read
                       BHUP      activity stopped by SIGHUP
                       BW        the file has been written
                       CLSG      closing
                       CX        close-on-exec (see fcntl(F_SETFD))
                       LCK       lock was applied
                       MP        memory-mapped
                       OPIP      open pending - in progress
                       RSVW      reserved wait
                       SHMT      UF_FSHMAT set (AIX)
                       USE       in use (multi-threaded)
    
           NODE-ID
                  (or INODE-ADDR for some dialects) contains a unique
                  identifier for the file node (usually the kernel vnode or
                  inode address, but also occasionally a concatenation of
                  device and node number) when **n** has been specified to **+f** ;
    
           DEVICE contains the device numbers, separated by commas, for a
                  character special, block special, regular, directory or NFS
                  file;
    
                  or ``memory'' for a memory file system node under Tru64
                  UNIX;
    
                  or the address of the private data area of a Solaris socket
                  stream;
    
                  or a kernel reference address that identifies the file (The
                  kernel reference address may be used for FIFO's, for
                  example.);
    
                  or the base address or device name of a Linux AX.25 socket
                  device.
    
                  Usually only the lower thirty two bits of Tru64 UNIX kernel
                  addresses are displayed.
    
           SIZE, SIZE/OFF, or OFFSET
                  is the size of the file or the file offset in bytes.  A
                  value is displayed in this column only if it is available.
                  _Lsof_ displays whatever value - size or offset - is
                  appropriate for the type of the file and the version of
                  _lsof_.
    
                  On some UNIX dialects _lsof_ can't obtain accurate or
                  consistent file offset information from its kernel data
                  sources, sometimes just for particular kinds of files
                  (e.g., socket files.)  In other cases, files don't have
                  true sizes - e.g., sockets, FIFOs, pipes - so _lsof_ displays
                  for their sizes the content amounts it finds in their
                  kernel buffer descriptors (e.g., socket buffer size counts
                  or TCP/IP window sizes.)  Consult the _lsof_ FAQ (The **FAQ**
                  section gives its location.)  for more information.
    
                  The file size is displayed in decimal; the offset is
                  normally displayed in decimal with a leading ``0t'' if it
                  contains 8 digits or less; in hexadecimal with a leading
                  ``0x'' if it is longer than 8 digits.  (Consult the **-o** _o_
                  option description for information on when 8 might default
                  to some other value.)
    
                  Thus the leading ``0t'' and ``0x'' identify an offset when
                  the column may contain both a size and an offset (i.e., its
                  title is SIZE/OFF).
    
                  If the **-o** option is specified, _lsof_ always displays the
                  file offset (or nothing if no offset is available) and
                  labels the column OFFSET.  The offset always begins with
                  ``0t'' or ``0x'' as described above.
    
                  The _lsof_ user can control the switch from ``0t'' to ``0x''
                  with the **-o** _o_ option.  Consult its description for more
                  information.
    
                  If the **-s** option is specified, _lsof_ always displays the
                  file size (or nothing if no size is available) and labels
                  the column SIZE.  The **-o** and **-s** options are mutually
                  exclusive; they can't both be specified.
    
                  If the **-H** option is specified, _lsof_ displays file size in
                  human readable form.
    
                  For files that don't have a fixed size - e.g., don't reside
                  on a disk device - _lsof_ will display appropriate
                  information about the current size or position of the file
                  if it is available in the kernel structures that define the
                  file.
    
           NLINK  contains the file link count when **+L** has been specified;
    
           NODE   is the node number of a local file;
    
                  or the inode number of an NFS file in the server host;
    
                  or the Internet protocol type - e.g, ``TCP'';
    
                  or ``STR'' for a stream;
    
                  or ``CCITT'' for an HP-UX x.25 socket;
    
                  or the IRQ or inode number of a Linux AX.25 socket device.
    
           NAME   is the name of the mount point and file system on which the
                  file resides;
    
                  or the name of a file specified in the _names_ option (after
                  any symbolic links have been resolved);
    
                  or the name of a character special or block special device;
    
                  or the local and remote Internet addresses of a network
                  file; the local host name or IP number is followed by a
                  colon (':'), the port, ``->'', and the two-part remote
                  address; IP addresses may be reported as numbers or names,
                  depending on the **+|-M** , **-n** , and **-P** options; colon-separated
                  IPv6 numbers are enclosed in square brackets; IPv4
                  INADDR_ANY and IPv6 IN6_IS_ADDR_UNSPECIFIED addresses, and
                  zero port numbers are represented by an asterisk ('*'); a
                  UDP destination address may be followed by the amount of
                  time elapsed since the last packet was sent to the
                  destination; TCP, UDP and UDPLITE remote addresses may be
                  followed by TCP/TPI information in parentheses - state
                  (e.g., ``(ESTABLISHED)'', ``(Unbound)''), queue sizes, and
                  window sizes (not all dialects) - in a fashion similar to
                  what **netstat**(1) reports; see the **-T** option description or
                  the description of the TCP/TPI field in **OUTPUT FOR OTHER**
                  **PROGRAMS** for more information on state, queue size, and
                  window size;
    
                  or the address or name of a UNIX domain socket, possibly
                  including a stream clone device name, a file system
                  object's path name, local and foreign kernel addresses,
                  socket pair information, and a bound vnode address;
    
                  or the local and remote mount point names of an NFS file;
    
                  or ``STR'', followed by the stream name;
    
                  or a stream character device name, followed by ``->'' and
                  the stream name or a list of stream module names, separated
                  by ``->'';
    
                  or ``STR:'' followed by the SCO OpenServer stream device
                  and module names, separated by ``->'';
    
                  or system directory name, `` -- '', and as many components
                  of the path name as _lsof_ can find in the kernel's name
                  cache for selected dialects (See the **KERNEL NAME CACHE**
                  section for more information.);
    
                  or ``PIPE->'', followed by a Solaris kernel pipe
                  destination address;
    
                  or ``COMMON:'', followed by the vnode device information
                  structure's device name, for a Solaris common vnode;
    
                  or the address family, followed by a slash (`/'), followed
                  by fourteen comma-separated bytes of a non-Internet raw
                  socket address;
    
                  or the HP-UX x.25 local address, followed by the virtual
                  connection number (if any), followed by the remote address
                  (if any);
    
                  or ``(dead)'' for disassociated Tru64 UNIX files -
                  typically terminal files that have been flagged with the
                  TIOCNOTTY ioctl and closed by daemons;
    
                  or ``rd=<offset>'' and ``wr=<offset>'' for the values of
                  the read and write offsets of a FIFO;
    
                  or ``clone _n_ :/dev/event'' for SCO OpenServer file clones of
                  the _/dev/event_ device, where _n_ is the minor device number
                  of the file;
    
                  or ``(socketpair: n)'' for a Solaris 2.6, 8, 9  or 10 UNIX
                  domain socket, created by the _socketpair_(3N) network
                  function;
    
                  or ``no PCB'' for socket files that do not have a protocol
                  block associated with them, optionally followed by ``,
                  CANTSENDMORE'' if sending on the socket has been disabled,
                  or ``, CANTRCVMORE'' if receiving on the socket has been
                  disabled (e.g., by the shutdown(2) function);
    
                  or the local and remote addresses of a Linux IPX socket
                  file in the form <net>:[<node>:]<port>, followed in
                  parentheses by the transmit and receive queue sizes, and
                  the connection state;
    
                  or ``dgram'' or ``stream'' for the type UnixWare 7.1.1 and
                  above in-kernel UNIX domain sockets, followed by a colon
                  (':') and the local path name when available, followed by
                  ``->'' and the remote path name or kernel socket address in
                  hexadecimal when available;
    
                  or the association value, association index, endpoint
                  value, local address, local port, remote address and remote
                  port for Linux SCTP sockets;
    
                  or ``protocol: '' followed by the Linux socket's protocol
                  attribute.
    
           For dialects that support a ``namefs'' file system, allowing one
           file to be attached to another with _fattach_(3C), _lsof_ will add
           ``(FA:<address1><direction><address2>)'' to the NAME column.
           <address1> and <address2> are hexadecimal vnode addresses.
           <direction> will be ``<-'' if <address2> has been fattach'ed to
           this vnode whose address is <address1>; and ``->'' if <address1>,
           the vnode address of this vnode, has been fattach'ed to
           <address2>.  <address1> may be omitted if it already appears in
           the DEVICE column.
    
           _Lsof_ may add two parenthetical notes to the NAME column for open
           Solaris 10 files: ``(?)'' if _lsof_ considers the path name of
           questionable accuracy; and ``(deleted)'' if the **-X** option has been
           specified and _lsof_ detects the open file's path name has been
           deleted.  Consult the _lsof_ FAQ (The **FAQ** section gives its
           location.)  for more information on these NAME column additions.
    


## LOCKS



           _Lsof_ can't adequately report the wide variety of UNIX dialect file
           locks in a single character.  What it reports in a single
           character is a compromise between the information it finds in the
           kernel and the limitations of the reporting format.
    
           Moreover, when a process holds several byte level locks on a file,
           _lsof_ only reports the status of the first lock it encounters.  If
           it is a byte level lock, then the lock character will be reported
           in lower case - i.e., `r', `w', or `x' - rather than the upper
           case equivalent reported for a full file lock.
    
           Generally _lsof_ can only report on locks held by local processes on
           local files.  When a local process sets a lock on a remotely
           mounted (e.g., NFS) file, the remote server host usually records
           the lock state.  One exception is Solaris - at some patch levels
           of 2.3, and in all versions above 2.4, the Solaris kernel records
           information on remote locks in local structures.
    
           _Lsof_ has trouble reporting locks for some UNIX dialects.  Consult
           the **BUGS** section of this manual page or the _lsof_ FAQ (The **FAQ**
           section gives its location.)  for more information.
    


## OUTPUT FOR OTHER PROGRAMS



           When the **-F** option is specified, _lsof_ produces output that is
           suitable for processing by another program - e.g, an _awk_ or _Perl_
           script, or a C program.
    
           Each unit of information is output in a field that is identified
           with a leading character and terminated by a NL (012) (or a NUL
           (000) if the 0 (zero) field identifier character is specified.)
           The data of the field follows immediately after the field
           identification character and extends to the field terminator.
    
           It is possible to think of field output as process and file sets.
           A process set begins with a field whose identifier is `p' (for
           process IDentifier (PID)).  It extends to the beginning of the
           next PID field or the beginning of the first file set of the
           process, whichever comes first.  Included in the process set are
           fields that identify the command, the process group IDentification
           (PGID) number, the task (thread) ID (TID), and the user ID (UID)
           number or login name.
    
           A file set begins with a field whose identifier is `f' (for file
           descriptor).  It is followed by lines that describe the file's
           access mode, lock state, type, device, size, offset, inode,
           protocol, name and stream module names.  It extends to the
           beginning of the next file or process set, whichever comes first.
    
           When the NUL (000) field terminator has been selected with the 0
           (zero) field identifier character, _lsof_ ends each process and file
           set with a NL (012) character.
    
           _Lsof_ always produces one field, the PID (`p') field.  In repeat
           mode, the marker (`m') is also produced.  All other fields may be
           declared optionally in the field identifier character list that
           follows the **-F** option.  When a field selection character
           identifies an item _lsof_ does not normally list - e.g., PPID,
           selected with **-R** - specification of the field character - e.g.,
           ``**-FR** '' - also selects the listing of the item.
    
           _Lsof_ version from 4.88 to 4.93.2 always produced one more field,
           the file descriptor (`f') field. However, _lsof_ in this version
           doesn't produce it. This change is for supporting the use case
           that a user needs only the PID field, and doesn't need the file
           descriptor field. Specify `f' explicitly if you need the field.
    
           It is entirely possible to select a set of fields that cannot
           easily be parsed - e.g., if the field descriptor field is not
           selected, it may be difficult to identify file sets.  To help you
           avoid this difficulty, _lsof_ supports the **-F** option; it selects the
           output of all fields with NL terminators (the **-F0** option pair
           selects the output of all fields with NUL terminators).  For
           compatibility reasons neither **-F** nor **-F0** select the raw device
           field.
    
           These are the fields that _lsof_ will produce.  The single character
           listed first is the field identifier.
    
                a    file access mode
                c    process command name (all characters from proc or
                     user structure)
                C    file structure share count
                d    file's device character code
                D    file's major/minor device number (0x<hexadecimal>)
                f    file descriptor
                F    file structure address (0x<hexadecimal>)
                G    file flaGs (0x<hexadecimal>; names if **+fg** follows)
                g    process group ID
                i    file's inode number
                K    tasK ID
                k    link count
                l    file's lock status
                L    process login name
                m    marker between repeated output (always selected in repeat mode)
                M    the task comMand name
                n    file name, comment, Internet address
                N    node identifier (ox<hexadecimal>
                o    file's offset (0t<decimal> or 0x<hexadecimal>, see **-o** _o_)
                p    process ID (always selected)
                P    protocol name
                r    raw device number (0x<hexadecimal>)
                R    parent process ID
                s    file's size (decimal)
                S    file's stream identification
                t    file's type
                T    TCP/TPI information, identified by prefixes (the
                     `=' is part of the prefix):
                         QR=<read queue size>
                         QS=<send queue size>
                         SO=<socket options and values> (not all dialects)
                         SS=<socket states> (not all dialects)
                         ST=<connection state>
                         TF=<TCP flags and values> (not all dialects)
                         WR=<window read size>  (not all dialects)
                         WW=<window write size>  (not all dialects)
                     (TCP/TPI information isn't reported for all supported
                       UNIX dialects. The **-h** or **-?** help output for the
                       **-T** option will show what TCP/TPI reporting can be
                       requested.)
                u    process user ID
                z    Solaris 10 and higher zone name
                Z    SELinux security context (inhibited when SELinux is disabled)
                0    use NUL field terminator character in place of NL
                1-9  dialect-specific field identifiers (The output
                     of **-F?** identifies the information to be found
                     in dialect-specific fields.)
    
           You can get on-line help information on these characters and their
           descriptions by specifying the **-F?** option pair.  (Escape the `?'
           character as your shell requires.)  Additional information on
           field content can be found in the **OUTPUT** section.
    
           As an example, ``**-F pcfn** '' will select the process ID (`p'),
           command name (`c'), file descriptor (`f') and file name (`n')
           fields with an NL field terminator character; ``**-F pcfn0** '' selects
           the same output with a NUL (000) field terminator character.
    
           _Lsof_ doesn't produce all fields for every process or file set,
           only those that are available.  Some fields are mutually
           exclusive: file device characters and file major/minor device
           numbers; file inode number and protocol name; file name and stream
           identification; file size and offset.  One or the other member of
           these mutually exclusive sets will appear in field output, but not
           both.
    
           Normally _lsof_ ends each field with a NL (012) character.  The 0
           (zero) field identifier character may be specified to change the
           field terminator character to a NUL (000).  A NUL terminator may
           be easier to process with xargs(1), for example, or with programs
           whose quoting mechanisms may not easily cope with the range of
           characters in the field output.  When the NUL field terminator is
           in use, _lsof_ ends each process and file set with a NL (012).
    
           Three aids to producing programs that can process _lsof_ field
           output are included in the _lsof_ distribution.  The first is a C
           header file, _lsof_fields.h_ , that contains symbols for the field
           identification characters, indexes for storing them in a table,
           and explanation strings that may be compiled into programs.  _Lsof_
           uses this header file.
    
           The second aid is a set of sample scripts that process field
           output, written in _awk_ , _Perl_ 4, and _Perl_ 5.  They're located in
           the _scripts_ subdirectory of the _lsof_ distribution.
    
           The third aid is the C library used for the _lsof_ test suite.  The
           test suite is written in C and uses field output to validate the
           correct operation of _lsof_.  The library can be found in the
           _tests/LTlib.c_ file of the _lsof_ distribution.  The library uses the
           first aid, the _lsof_fields.h_ header file.
    


## BLOCKS AND TIMEOUTS



           _Lsof_ can be blocked by some kernel functions that it uses -
           lstat(2), readlink(2), and stat(2).  These functions are stalled
           in the kernel, for example, when the hosts where mounted NFS file
           systems reside become inaccessible.
    
           _Lsof_ attempts to break these blocks with timers and child
           processes, but the techniques are not wholly reliable.  When _lsof_
           does manage to break a block, it will report the break with an
           error message.  The messages may be suppressed with the **-t** and **-w**
           options.
    
           The default timeout value may be displayed with the **-h** or **-?**
           option, and it may be changed with the **-S** _[t]_ option.  The minimum
           for _t_ is two seconds, but you should avoid small values, since
           slow system responsiveness can cause short timeouts to expire
           unexpectedly and perhaps stop _lsof_ before it can produce any
           output.
    
           When _lsof_ has to break a block during its access of mounted file
           system information, it normally continues, although with less
           information available to display about open files.
    
           _Lsof_ can also be directed to avoid the protection of timers and
           child processes when using the kernel functions that might block
           by specifying the **-O** option.  While this will allow _lsof_ to start
           up with less overhead, it exposes _lsof_ completely to the kernel
           situations that might block it.  Use this option cautiously.
    


## AVOIDING KERNEL BLOCKS



           You can use the **-b** option to tell _lsof_ to avoid using kernel
           functions that would block.  Some cautions apply.
    
           First, using this option usually requires that your system supply
           alternate device numbers in place of the device numbers that _lsof_
           would normally obtain with the lstat(2) and stat(2) kernel
           functions.  See the **ALTERNATE DEVICE NUMBERS** section for more
           information on alternate device numbers.
    
           Second, you can't specify _names_ for _lsof_ to locate unless they're
           file system names.  This is because _lsof_ needs to know the device
           and inode numbers of files listed with _names_ in the _lsof_ options,
           and the **-b** option prevents _lsof_ from obtaining them.  Moreover,
           since _lsof_ only has device numbers for the file systems that have
           alternates, its ability to locate files on file systems depends
           completely on the availability and accuracy of the alternates.  If
           no alternates are available, or if they're incorrect, _lsof_ won't
           be able to locate files on the named file systems.
    
           Third, if the names of your file system directories that _lsof_
           obtains from your system's mount table are symbolic links, _lsof_
           won't be able to resolve the links.  This is because the **-b** option
           causes _lsof_ to avoid the kernel readlink(2) function it uses to
           resolve symbolic links.
    
           Finally, using the **-b** option causes _lsof_ to issue warning messages
           when it needs to use the kernel functions that the **-b** option
           directs it to avoid.  You can suppress these messages by
           specifying the **-w** option, but if you do, you won't see the
           alternate device numbers reported in the warning messages.
    


## ALTERNATE DEVICE NUMBERS



           On some dialects, when _lsof_ has to break a block because it can't
           get information about a mounted file system via the lstat(2) and
           stat(2) kernel functions, or because you specified the **-b** option,
           _lsof_ can obtain some of the information it needs - the device
           number and possibly the file system type - from the system mount
           table.  When that is possible, _lsof_ will report the device number
           it obtained.  (You can suppress the report by specifying the **-w**
           option.)
    
           You can assist this process if your mount table is supported with
           an _/etc/mtab_ or _/etc/mnttab_ file that contains an options field by
           adding a ``dev=xxxx'' field for mount points that do not have one
           in their options strings.  Note: you must be able to edit the file
           - i.e., some mount tables like recent Solaris /etc/mnttab or Linux
           /proc/mounts are read-only and can't be modified.
    
           You may also be able to supply device numbers using the **+m** and **+m**
           _m_ options, provided they are supported by your dialect.  Check the
           output of _lsof's_ **-h** or **-?** options to see if the **+m** and **+m** _m_
           options are available.
    
           The ``xxxx'' portion of the field is the hexadecimal value of the
           file system's device number.  (Consult the _st_dev_ field of the
           output of the lstat(2) and stat(2) functions for the appropriate
           values for your file systems.)  Here's an example from a Sun
           Solaris 2.6 _/etc/mnttab_ for a file system remotely mounted via
           NFS:
    
                nfs  ignore,noquota,dev=2a40001
    
           There's an advantage to having ``dev=xxxx'' entries in your mount
           table file, especially for file systems that are mounted from
           remote NFS servers.  When a remote server crashes and you want to
           identify its users by running _lsof_ on one of its clients, _lsof_
           probably won't be able to get output from the lstat(2) and stat(2)
           functions for the file system.  If it can obtain the file system's
           device number from the mount table, it will be able to display the
           files open on the crashed NFS server.
    
           Some dialects that do not use an ASCII _/etc/mtab_ or _/etc/mnttab_
           file for the mount table may still provide an alternative device
           number in their internal mount tables.  This includes AIX, Apple
           Darwin, FreeBSD, NetBSD, OpenBSD, and Tru64 UNIX.  _Lsof_ knows how
           to obtain the alternative device number for these dialects and
           uses it when its attempt to lstat(2) or stat(2) the file system is
           blocked.
    
           If you're not sure your dialect supplies alternate device numbers
           for file systems from its mount table, use this _lsof_ incantation
           to see if it reports any alternate device numbers:
    
                  lsof -b
    
           Look for standard error file warning messages that begin
           ``assuming "dev=xxxx" from ...''.
    


## KERNEL NAME CACHE



           _Lsof_ is able to examine the kernel's name cache or use other
           kernel facilities (e.g., the ADVFS 4.x tag_to_path() function
           under Tru64 UNIX) on some dialects for most file system types,
           excluding AFS, and extract recently used path name components from
           it.  (AFS file system path lookups don't use the kernel's name
           cache; some Solaris VxFS file system operations apparently don't
           use it, either.)
    
           _Lsof_ reports the complete paths it finds in the NAME column.  If
           _lsof_ can't report all components in a path, it reports in the NAME
           column the file system name, followed by a space, two `-'
           characters, another space, and the name components it has located,
           separated by the `/' character.
    
           When _lsof_ is run in repeat mode - i.e., with the **-r** option
           specified - the extent to which it can report path name components
           for the same file may vary from cycle to cycle.  That's because
           other running processes can cause the kernel to remove entries
           from its name cache and replace them with others.
    
           _Lsof's_ use of the kernel name cache to identify the paths of files
           can lead it to report incorrect components under some
           circumstances.  This can happen when the kernel name cache uses
           device and node number as a key (e.g., SCO OpenServer) and a key
           on a rapidly changing file system is reused.  If the UNIX
           dialect's kernel doesn't purge the name cache entry for a file
           when it is unlinked, _lsof_ may find a reference to the wrong entry
           in the cache.  The _lsof_ FAQ (The **FAQ** section gives its location.)
           has more information on this situation.
    
           _Lsof_ can report path name components for these dialects:
    
                FreeBSD
                HP-UX
                Linux
                NetBSD
                SCO OpenServer
                SCO|Caldera UnixWare
                Solaris
                Tru64 UNIX
    
           _Lsof_ can't report path name components for these dialects:
    
                AIX
                OpenBSD
    
           If you want to know why _lsof_ can't report path name components for
           some dialects, see the _lsof_ FAQ (The **FAQ** section gives its
           location.)
    


## DEVICE CACHE FILE



           Examining all members of the _/dev_ (or _/devices_) node tree with
           stat(2) functions can be time consuming.  What's more, the
           information that _lsof_ needs - device number, inode number, and
           path - rarely changes.
    
           Consequently, _lsof_ normally maintains an ASCII text file of cached
           _/dev_ (or _/devices_) information (exception: the /proc-based Linux
           _lsof_ where it's not needed.)  The local system administrator who
           builds _lsof_ can control the way the device cache file path is
           formed, selecting from these options:
    
                Path from the **-D** option;
                Path from an environment variable;
                System-wide path;
                Personal path (the default);
                Personal path, modified by an environment variable.
    
           Consult the output of the **-h** , **-D? ,** or **-?** help options for the
           current state of device cache support.  The help output lists the
           default read-mode device cache file path that is in effect for the
           current invocation of _lsof_.  The **-D?** option output lists the
           read-only and write device cache file paths, the names of any
           applicable environment variables, and the personal device cache
           path format.
    
           _Lsof_ can detect that the current device cache file has been
           accidentally or maliciously modified by integrity checks,
           including the computation and verification of a sixteen bit Cyclic
           Redundancy Check (CRC) sum on the file's contents.  When _lsof_
           senses something wrong with the file, it issues a warning and
           attempts to remove the current cache file and create a new copy,
           but only to a path that the process can legitimately write.
    
           The path from which a _lsof_ process may attempt to read a device
           cache file may not be the same as the path to which it can
           legitimately write.  Thus when _lsof_ senses that it needs to update
           the device cache file, it may choose a different path for writing
           it from the path from which it read an incorrect or outdated
           version.
    
           If available, the **-Dr** option will inhibit the writing of a new
           device cache file.  (It's always available when specified without
           a path name argument.)
    
           When a new device is added to the system, the device cache file
           may need to be recreated.  Since _lsof_ compares the mtime of the
           device cache file with the mtime and ctime of the _/dev_ (or
           _/devices_) directory, it usually detects that a new device has been
           added; in that case _lsof_ issues a warning message and attempts to
           rebuild the device cache file.
    
           Whenever _lsof_ writes a device cache file, it sets its ownership to
           the real UID of the executing process, and its permission modes to
           0600, this restricting its reading and writing to the file's
           owner.
    


## LSOF PERMISSIONS THAT AFFECT DEVICE CACHE FILE ACCESS



           Two permissions of the _lsof_ executable affect its ability to
           access device cache files.  The permissions are set by the local
           system administrator when _lsof_ is installed.
    
           The first and rarer permission is setuid-root.  It comes into
           effect when _lsof_ is executed; its effective UID is then root,
           while its real (i.e., that of the logged-on user) UID is not.  The
           _lsof_ distribution recommends that versions for these dialects run
           setuid-root.
    
                HP-UX 11.11 and 11.23
                Linux
    
           The second and more common permission is setgid.  It comes into
           effect when the effective group IDentification number (GID) of the
           _lsof_ process is set to one that can access kernel memory devices -
           e.g., ``kmem'', ``sys'', or ``system''.
    
           An _lsof_ process that has setgid permission usually surrenders the
           permission after it has accessed the kernel memory devices.  When
           it does that, _lsof_ can allow more liberal device cache path
           formations.  The _lsof_ distribution recommends that versions for
           these dialects run setgid and be allowed to surrender setgid
           permission.
    
                AIX 5.[12] and 5.3-ML1
                Apple Darwin 7.x Power Macintosh systems
                FreeBSD 4.x, 4.1x, 5.x and [6789].x for x86-based systems
                FreeBSD 5.x, [6789].x and 1[012].8for Alpha, AMD64 and Sparc64
                    based systems
                HP-UX 11.00
                NetBSD 1.[456], 2.x and 3.x for Alpha, x86, and SPARC-based
                    systems
                OpenBSD 2.[89] and 3.[0-9] for x86-based systems
                SCO OpenServer Release 5.0.6 for x86-based systems
                SCO|Caldera UnixWare 7.1.4 for x86-based systems
                Solaris 2.6, 8, 9 and 10
                Tru64 UNIX 5.1
    
           (Note: _lsof_ for AIX 5L and above needs setuid-root permission if
           its **-X** option is used.)
    
           _Lsof_ for these dialects does not support a device cache, so the
           permissions given to the executable don't apply to the device
           cache file.
    
                Linux
    


## DEVICE CACHE FILE PATH FROM THE -D OPTION



           The **-D** option provides limited means for specifying the device
           cache file path.  Its **?** function will report the read-only and
           write device cache file paths that _lsof_ will use.
    
           When the **-D b** , **r** , and **u** functions are available, you can use them
           to request that the cache file be built in a specific location
           (**b**[_path_]); read but not rebuilt (**r**[_path_]); or read and rebuilt
           (**u**[_path_]).  The **b** , **r** , and **u** functions are restricted under some
           conditions.  They are restricted when the _lsof_ process is
           setuid-root.  The path specified with the **r** function is always
           read-only, even when it is available.
    
           The **b** , **r** , and **u** functions are also restricted when the _lsof_
           process runs setgid and _lsof_ doesn't surrender the setgid
           permission.  (See the **LSOF PERMISSIONS THAT AFFECT DEVICE CACHE**
           **FILE ACCESS** section for a list of implementations that normally
           don't surrender their setgid permission.)
    
           A further **-D** function, **i**(for ignore), is always available.
    
           When available, the **b** function tells _lsof_ to read device
           information from the kernel with the stat(2) function and build a
           device cache file at the indicated path.
    
           When available, the **r** function tells _lsof_ to read the device cache
           file, but not update it.  When a path argument accompanies **-Dr** , it
           names the device cache file path.  The **r** function is always
           available when it is specified without a path name argument.  If
           _lsof_ is not running setuid-root and surrenders its setgid
           permission, a path name argument may accompany the **r** function.
    
           When available, the **u** function tells _lsof_ to attempt to read and
           use the device cache file.  If it can't read the file, or if it
           finds the contents of the file incorrect or outdated, it will read
           information from the kernel, and attempt to write an updated
           version of the device cache file, but only to a path it considers
           legitimate for the _lsof_ process effective and real UIDs.
    


## DEVICE CACHE PATH FROM AN ENVIRONMENT VARIABLE



           _Lsof's_ second choice for the device cache file is the contents of
           the LSOFDEVCACHE environment variable.  It avoids this choice if
           the _lsof_ process is setuid-root, or the real UID of the process is
           root.
    
           A further restriction applies to a device cache file path taken
           from the LSOFDEVCACHE environment variable: _lsof_ will not write a
           device cache file to the path if the _lsof_ process doesn't
           surrender its setgid permission.  (See the **LSOF PERMISSIONS THAT**
           **AFFECT DEVICE CACHE FILE ACCESS** section for information on
           implementations that don't surrender their setgid permission.)
    
           The local system administrator can disable the use of the
           LSOFDEVCACHE environment variable or change its name when building
           _lsof_.  Consult the output of **-D?** for the environment variable's
           name.
    


## SYSTEM-WIDE DEVICE CACHE PATH



           The local system administrator may choose to have a system-wide
           device cache file when building _lsof_.  That file will generally be
           constructed by a special system administration procedure when the
           system is booted or when the contents of _/dev_ or _/devices_)
           changes.  If defined, it is _lsof's_ third device cache file path
           choice.
    
           You can tell that a system-wide device cache file is in effect for
           your local installation by examining the _lsof_ help option output -
           i.e., the output from the **-h** or **-?** option.
    
           _Lsof_ will never write to the system-wide device cache file path by
           default.  It must be explicitly named with a **-D** function in a
           root-owned procedure.  Once the file has been written, the
           procedure must change its permission modes to 0644 (owner-read and
           owner-write, group-read, and other-read).
    


## PERSONAL DEVICE CACHE PATH (DEFAULT)



           The default device cache file path of the _lsof_ distribution is one
           recorded in the home directory of the real UID that executes _lsof_.
           Added to the home directory is a second path component of the form
           _.lsof_hostname_.
    
           This is _lsof's_ fourth device cache file path choice, and is
           usually the default.  If a system-wide device cache file path was
           defined when _lsof_ was built, this fourth choice will be applied
           when _lsof_ can't find the system-wide device cache file.  This is
           the **only** time _lsof_ uses two paths when reading the device cache
           file.
    
           The _hostname_ part of the second component is the base name of the
           executing host, as returned by gethostname(2).  The base name is
           defined to be the characters preceding the first `.'  in the
           gethostname(2) output, or all the gethostname(2) output if it
           contains no `.'.
    
           The device cache file belongs to the user ID and is readable and
           writable by the user ID alone - i.e., its modes are 0600.  Each
           distinct real user ID on a given host that executes _lsof_ has a
           distinct device cache file.  The _hostname_ part of the path
           distinguishes device cache files in an NFS-mounted home directory
           into which device cache files are written from several different
           hosts.
    
           The personal device cache file path formed by this method
           represents a device cache file that _lsof_ will attempt to read, and
           will attempt to write should it not exist or should its contents
           be incorrect or outdated.
    
           The **-Dr** option without a path name argument will inhibit the
           writing of a new device cache file.
    
           The **-D?** option will list the format specification for
           constructing the personal device cache file.  The conversions used
           in the format specification are described in the _00DCACHE_ file of
           the _lsof_ distribution.
    


## MODIFIED PERSONAL DEVICE CACHE PATH



           If this option is defined by the local system administrator when
           _lsof_ is built, the LSOFPERSDCPATH environment variable contents
           may be used to add a component of the personal device cache file
           path.
    
           The LSOFPERSDCPATH variable contents are inserted in the path at
           the place marked by the local system administrator with the ``%p''
           conversion in the HASPERSDC format specification of the dialect's
           _machine.h_ header file.  (It's placed right after the home
           directory in the default _lsof_ distribution.)
    
           Thus, for example, if LSOFPERSDCPATH contains ``LSOF'', the home
           directory is ``/Homes/abe'', the host name is
           ``lsof.itap.purdue.edu'', and the HASPERSDC format is the default
           (``%h/%p.lsof_%L''), the modified personal device cache file path
           is:
    
                /Homes/abe/LSOF/.lsof_vic
    
           The LSOFPERSDCPATH environment variable is ignored when the _lsof_
           process is setuid-root or when the real UID of the process is
           root.
    
           _Lsof_ will not write to a modified personal device cache file path
           if the _lsof_ process doesn't surrender setgid permission.  (See the
           **LSOF PERMISSIONS THAT AFFECT DEVICE CACHE FILE ACCESS** section for
           a list of implementations that normally don't surrender their
           setgid permission.)
    
           If, for example, you want to create a sub-directory of personal
           device cache file paths by using the LSOFPERSDCPATH environment
           variable to name it, and _lsof_ doesn't surrender its setgid
           permission, you will have to allow _lsof_ to create device cache
           files at the standard personal path and move them to your
           subdirectory with shell commands.
    
           The local system administrator may: disable this option when _lsof_
           is built; change the name of the environment variable from
           LSOFPERSDCPATH to something else; change the HASPERSDC format to
           include the personal path component in another place; or exclude
           the personal path component entirely.  Consult the output of the
           **-D?** option for the environment variable's name and the HASPERSDC
           format specification.
    


## DIAGNOSTICS



           Errors are identified with messages on the standard error file.
    
           _Lsof_ returns a one (1) if any error was detected, including the
           failure to locate command names, file names, Internet addresses or
           files, login names, NFS files, PIDs, PGIDs, or UIDs it was asked
           to list.  If the **-V** option is specified, _lsof_ will indicate the
           search items it failed to list.  If the **-Q** option is specified,
           _lsof_ will ignore any search item failures and only return an error
           if something unusual and unrecoverable happened.
    
           It returns a zero (0) if no errors were detected and if either the
           **-Q** option was specified or it was able to list some information
           about all the specified search arguments.
    
           When _lsof_ cannot open access to _/dev_ (or _/devices_) or one of its
           subdirectories, or get information on a file in them with stat(2),
           it issues a warning message and continues.  That _lsof_ will issue
           warning messages about inaccessible files in _/dev_ (or _/devices_) is
           indicated in its help output - requested with the **-h** or >B -?
           options -  with the message:
    
                Inaccessible /dev warnings are enabled.
    
           The warning message may be suppressed with the **-w** option.  It may
           also have been suppressed by the system administrator when _lsof_
           was compiled by the setting of the WARNDEVACCESS definition.  In
           this case, the output from the help options will include the
           message:
    
                Inaccessible /dev warnings are disabled.
    
           Inaccessible device warning messages usually disappear after _lsof_
           has created a working device cache file.
    


## EXAMPLES



           For a more extensive set of examples, documented more fully, see
           the _00QUICKSTART_ file of the _lsof_ distribution.
    
           To list all open files, use:
    
                  lsof
    
           To list all open Internet, x.25 (HP-UX), and UNIX domain files,
           use:
    
                  lsof -i -U
    
           To list all open IPv4 network files in use by the process whose
           PID is 1234, use:
    
                  lsof -i 4 -a -p 1234
    
           If it's okay for PID 1234 to not exist, or for PID 1234 to not
           have any open IPv4 network files, add **-Q** :
    
                  lsof -Q -i 4 -a -p 1234
    
           Presuming the UNIX dialect supports IPv6, to list only open IPv6
           network files, use:
    
                  lsof -i 6
    
           To list all files using any protocol on ports 513, 514, or 515 of
           host wonderland.cc.purdue.edu, use:
    
                  lsof -i @wonderland.cc.purdue.edu:513-515
    
           To list all files using any protocol on any port of
           mace.cc.purdue.edu (cc.purdue.edu is the default domain), use:
    
                  lsof -i @mace
    
           To list all open files for login name ``abe'', or user ID 1234, or
           process 456, or process 123, or process 789, use:
    
                  lsof -p 456,123,789 -u 1234,abe
    
           To list all open files on device /dev/hd4, use:
    
                  lsof /dev/hd4
    
           To find the process that has /u/abe/foo open without worrying if
           there are none, use:
    
                  lsof -Q /u/abe/foo
    
           To take action only if a process has /u/abe/foo open, use:
    
                  lsof /u/abe/foo  echo "still in use"
    
           To send a SIGHUP to the processes that have /u/abe/bar open, use:
    
                  kill -HUP `lsof -t /u/abe/bar`
    
           To find any open file, including an open UNIX domain socket file,
           with the name _/dev/log_ , use:
    
                  lsof /dev/log
    
           To find processes with open files on the NFS file system named
           _/nfs/mount/point_ whose server is inaccessible, and presuming your
           mount table supplies the device number for _/nfs/mount/point_ , use:
    
                  lsof -b /nfs/mount/point
    
           To do the preceding search with warning messages suppressed, use:
    
                  lsof -bw /nfs/mount/point
    
           To ignore the device cache file, use:
    
                  lsof -Di
    
           To obtain PID and command name field output for each process, file
           descriptor, file device number, and file inode number for each
           file of each process, use:
    
                  lsof -FpcfDi
    
           To list the files at descriptors 1 and 3 of every process running
           the _lsof_ command for login ID ``abe'' every 10 seconds, use:
    
                  lsof -c lsof -a -d 1 -d 3 -u abe -r10
    
           To list the current working directory of processes running a
           command that is exactly four characters long and has an 'o' or 'O'
           in character three, use this regular expression form of the **-c** _c_
           option:
    
                  lsof -c /^..o.$/i -a -d cwd
    
           To find an IP version 4 socket file by its associated numeric
           dot-form address, use:
    
                  lsof -i@128.210.15.17
    
           To find an IP version 6 socket file (when the UNIX dialect
           supports IPv6) by its associated numeric colon-form address, use:
    
                  lsof -i@[0:1:2:3:4:5:6:7]
    
           To find an IP version 6 socket file (when the UNIX dialect
           supports IPv6) by an associated numeric colon-form address that
           has a run of zeroes in it - e.g., the loop-back address - use:
    
                  lsof -i@[::1]
    
           To obtain a repeat mode marker line that contains the current
           time, use:
    
                  lsof -rm====%T====
    
           To add spaces to the previous marker line, use:
    
                  lsof -r "m==== %T ===="
    


## BUGS



           Since _lsof_ reads kernel memory in its search for open files, rapid
           changes in kernel memory may produce unpredictable results.
    
           When a file has multiple record locks, the lock status character
           (following the file descriptor) is derived from a test of the
           first lock structure, not from any combination of the individual
           record locks that might be described by multiple lock structures.
    
           _Lsof_ can't search for files with restrictive access permissions by
           _name_ unless it is installed with root set-UID permission.
           Otherwise it is limited to searching for files to which its user
           or its set-GID group (if any) has access permission.
    
           The display of the destination address of a raw socket (e.g., for
           _ping_) depends on the UNIX operating system.  Some dialects store
           the destination address in the raw socket's protocol control
           block, some do not.
    
           _Lsof_ can't always represent Solaris device numbers in the same way
           that ls(1) does.  For example, the major and minor device numbers
           that the lstat(2) and stat(2) functions report for the directory
           on which CD-ROM files are mounted (typically _/cdrom_) are not the
           same as the ones that it reports for the device on which CD-ROM
           files are mounted (typically _/dev/sr0_).  (_Lsof_ reports the
           directory numbers.)
    
           The support for _/proc_ file systems is available only for BSD and
           Tru64 UNIX dialects, Linux, and dialects derived from SYSV R4 -
           e.g., FreeBSD, NetBSD, OpenBSD, Solaris, UnixWare.
    
           Some _/proc_ file items - device number, inode number, and file size
           - are unavailable in some dialects.  Searching for files in a
           _/proc_ file system may require that the full path name be
           specified.
    
           No text (**txt**) file descriptors are displayed for Linux processes.
           All entries for files other than the current working directory,
           the root directory, and numerical file descriptors are labeled **mem**
           descriptors.
    
           _Lsof_ can't search for Tru64 UNIX named pipes by name, because
           their kernel implementation of lstat(2) returns an improper device
           number for a named pipe.
    
           _Lsof_ can't report fully or correctly on HP-UX 9.01, 10.20, and
           11.00 locks because of insufficient access to kernel data or
           errors in the kernel data.  See the _lsof_ FAQ (The **FAQ** section
           gives its location.)  for details.
    
           The AIX SMT file type is a fabrication.  It's made up for file
           structures whose type (15) isn't defined in the AIX
           _/usr/include/sys/file.h_ header file.  One way to create such file
           structures is to run X clients with the DISPLAY variable set to
           ``:0.0''.
    
           The **+|-f** _[cfn]_ option is not supported under /proc-based Linux
           _lsof_ , because it doesn't read kernel structures from kernel
           memory.
    


## ENVIRONMENT



           _Lsof_ may access these environment variables.
    
           LANG   defines a language locale.  See setlocale(3) for the names
                  of other variables that can be used in place of LANG -
                  e.g., LC_ALL, LC_TYPE, etc.
    
           LSOFDEVCACHE
                  defines the path to a device cache file.  See the **DEVICE**
                  **CACHE PATH FROM AN ENVIRONMENT VARIABLE** section for more
                  information.
    
           LSOFPERSDCPATH
                  defines the middle component of a modified personal device
                  cache file path.  See the **MODIFIED PERSONAL DEVICE CACHE**
                  **PATH** section for more information.
    


## FAQ



           Frequently-asked questions and their answers (an FAQ) are
           available in the _00FAQ_ file of the _lsof_ distribution.
    
           That latest version of the file is found at:
    
                  https://github.com/lsof-org/lsof/blob/master/00FAQ
    


## FILES



           _/dev/kmem_
                  kernel virtual memory device
    
           _/dev/mem_
                  physical memory device
    
           _/dev/swap_
                  system paging device
    
           _.lsof_hostname_
                  _lsof's_ device cache file (The suffix, _hostname_ , is the
                  first component of the host's name returned by
                  gethostname(2).)
    


## DISTRIBUTION



           The latest distribution of _lsof_ is available at
    
                  https://github.com/lsof-org/lsof/releases
    


* * *