neulab/tldr huggingface dataset:
The strip command is useful for reloading configuration files without disrupting active sessions:
# wg syncconf wgnet0 <(wg-quick strip wgnet0)
wg(8), ip(8), ip-link(8), ip-address(8), ip-route(8), ip-rule(8), resolvconf(8).
wg-quick was written by Jason A. Donenfeld ⟨Jason@zx2c4.com⟩.  For updates and more information, a project page is available on the World Wide Web ⟨https://www.wireguard.com/⟩.
ASCIIDOCTOR(1)                 Asciidoctor Manual                 ASCIIDOCTOR(1)
asciidoctor - converts AsciiDoc source files to HTML, DocBook, and other formats
asciidoctor [OPTION]... FILE...
The asciidoctor(1) command converts the AsciiDoc source file(s) FILE to HTML5, DocBook 5, man(ual) page, and other custom output formats.
If FILE is - then the AsciiDoc source is read from standard input.
Security Settings -B, --base-dir=DIR Base directory containing the document and resources. Defaults to the directory containing the source file or, if the source is read from a stream, the working directory. When combined with the safe mode setting, can be used to chroot the execution of the program.
-S, --safe-mode=SAFE_MODE Set safe mode level: unsafe, safe, server, or secure. Disables potentially dangerous macros in source files, such as include::[]. If not set, the safe mode level defaults to unsafe when Asciidoctor is invoked using this script.
--safe Set safe mode level to safe. Enables include directives, but prevents access to ancestor paths of source file. Provided for compatibility with the asciidoc command. If not set, the safe mode level defaults to unsafe when Asciidoctor is invoked using this script.
Document Settings -a, --attribute=ATTRIBUTE Define, override, or unset a document attribute. Command-line attributes take precedence over attributes defined in the source file unless either the name or value ends in @.
ATTRIBUTE is normally formatted as a key-value pair, in the form NAME=VALUE. Alternate forms are NAME (where the VALUE defaults to an empty string), NAME! (unsets the NAME attribute), and NAME=VALUE@ (or NAME@=VALUE) (where VALUE does not override the NAME attribute if itâ€™s already defined in the source document). Values containing spaces should be enclosed in quotes.
-b, --backend=BACKEND Backend output file format: html5, docbook5, and manpage are supported out of the box. You can also use the backend alias names html (aliased to html5) or docbook (aliased to docbook5). Other values can be passed, but if Asciidoctor cannot resolve the backend to a converter, it will fail. Defaults to html5.
-d, --doctype=DOCTYPE Document type: article, book, manpage, or inline. Sets the root element when using the docbook backend and the style class on the HTML body element when using the html backend. The book document type allows multiple level-0 section titles in a single document. The manpage document type enables parsing of metadata necessary to produce a man page. The inline document type allows the content of a single paragraph to be formatted and returned without wrapping it in a containing element. Defaults to article.
Document Conversion -D, --destination-dir=DIR Destination output directory. Defaults to the directory containing the source file or, if the source is read from a stream, the working directory. If specified, the directory is resolved relative to the working directory.
-E, --template-engine=NAME Template engine to use for the custom converter templates. The gem with the same name as the engine will be loaded automatically. This name is also used to build the full path to the custom converter templates. If a template engine is not specified, it will be auto-detected based on the file extension of the custom converter templates found.
-e, --embedded Output an embeddable document, which excludes the header, the footer, and everything outside the body of the document. This option is useful for producing documents that can be inserted into an external template.
-I, --load-path=DIRECTORY Add the specified directory to the load path, so that -r can load extensions from outside the default Ruby load path. This option may be specified more than once.
-n, --section-numbers Auto-number section titles. Synonym for --attribute sectnums.
-o, --out-file=OUT_FILE Write output to file OUT_FILE. Defaults to the base name of the input file suffixed with backend extension. The file is resolved relative to the working directory. If the input is read from standard input or a named pipe (fifo), then the output file defaults to stdout. If OUT_FILE is -, then the output file is written to standard output.
-R, --source-dir=DIR Source directory. Currently only used if the destination directory is also specified. Used to preserve the directory structure of files converted within this directory in the destination directory. If specified, the directory is resolved relative to the working directory.
-r, --require=LIBRARY Require the specified library before executing the processor, using the standard Ruby require. This option may be specified more than once.
-s, --no-header-footer Output an embeddable document, which excludes the header, the footer, and everything outside the body of the document. This option is useful for producing documents that can be inserted into an external template.
-T, --template-dir=DIR A directory containing custom converter templates that override one or more templates from the built-in set. (requires tilt gem)
If there is a subfolder that matches the engine name (if specified), that folder is appended to the template directory path. Similarly, if there is a subfolder in the resulting template directory that matches the name of the backend, that folder is appended to the template directory path.
This option may be specified more than once. Matching templates found in subsequent directories override ones previously discovered.
Processing Information --failure-level=LEVEL The minimum logging level that triggers a non-zero exit code (failure). If this option is not set (default: FATAL), the program exits with exit code zero even if warnings or errors have been logged.
-q, --quiet Silence application log messages and script warnings.
--trace Include backtrace information when reporting errors.
-v, --verbose Sets log level to DEBUG so application messages logged at INFO or DEBUG level are printed to stderr.
-w, --warnings Turn on script warnings (applies to executed code).
-t, --timings Print timings report to stderr (time to read, parse, and convert).
Program Information -h, --help [TOPIC] Print a help message. Show the command usage if TOPIC is not specified or recognized. Dump the Asciidoctor man page (in troff/groff format) if TOPIC is manpage.
-V, --version Print program version number.
-v can also be used if no source files are specified.
Asciidoctor honors the SOURCE_DATE_EPOCH environment variable. If this variable is assigned an integer value, that value is used as the epoch of all input documents and as the local date and time. See https://reproducible-builds.org/specs/source-date-epoch/ for more information about this environment variable.
0 Success.
1 Failure (syntax or usage error; configuration error; document processing failure; unexpected error).
Refer to the Asciidoctor issue tracker at https://github.com/asciidoctor/asciidoctor/issues?q=is%3Aopen.
Asciidoctor was written by Dan Allen, Ryan Waldron, Jason Porter, Nick Hengeveld, and other contributors.
AsciiDoc was written by Stuart Rackham and has received contributions from many other individuals.
Dan Allen
Sarah White
Ryan Waldron
Project web site: https://asciidoctor.org
Git source repository on GitHub: https://github.com/asciidoctor/asciidoctor
GitHub organization: https://github.com/asciidoctor
Discussion list / forum: http://discuss.asciidoctor.org
Copyright (C) 2012-present Dan Allen, Ryan Waldron, and the Asciidoctor Project. Free use of this software is granted under the terms of the MIT License.
ntpq(1)                           User Commands                          ntpq(1)
ntpq - standard NTP query program
ntpq [-flags] [-flag [value]] [--option-name[[=| ]value]] [ host ...]
The ntpq utility program is used to query NTP servers to monitor NTP operations and performance, requesting information about current state and/or changes in that state.  The program may be run either in interactive mode or controlled using command line arguments.  Requests to read and write arbitrary variables can be assembled, with raw and pretty- printed output options being available.  The ntpq utility can also obtain and print a list of peers in a common format by sending multiple queries to the server.
If one or more request options is included on the command line when ntpq is executed, each of the requests will be sent to the NTP servers running on each of the hosts given as command line arguments, or on localhost by default.  If no request options are given, ntpq will attempt to read commands from the standard input and execute these on the NTP server running on the first host given on the command line, again defaulting to localhost when no other host is specified.  The ntpq utility will prompt for commands if the standard input is a terminal device.
ntpq uses NTP mode 6 packets to communicate with the NTP server, and hence can be used to query any compatible server on the network which permits it.  Note that since NTP is a UDP protocol this communication will be somewhat unreliable, especially over large distances in terms of network topology.  The ntpq utility makes one attempt to retransmit requests, and will time requests out if the remote host is not heard from within a suitable timeout time.
Note that in contexts where a host name is expected, a -4 qualifier preceding the host name forces resolution to the IPv4 namespace, while a -6 qualifier forces resolution to the IPv6 namespace.  For examples and usage, see the NTP Debugging Techniques page.
Specifying a command line option other than -i or -n will cause the specified query (queries) to be sent to the indicated host(s) immediately.  Otherwise, ntpq will attempt to read interactive format commands from the standard input.
Internal Commands Interactive format commands consist of a keyword followed by zero to four arguments.  Only enough characters of the full keyword to uniquely identify the command need be typed.
A number of interactive format commands are executed entirely within the ntpq utility itself and do not result in NTP requests being sent to a server.  These are described following.
Control Message Commands Association ids are used to identify system, peer and clock variables. System variables are assigned an association id of zero and system name space, while each association is assigned a nonzero association id and peer namespace.  Most control commands send a single message to the server and expect a single response message.  The exceptions are the peers command, which sends a series of messages, and the mreadlist and mreadvar commands, which iterate over a range of associations.
apeers    Display a list of peers in the form: where the output is just like the peers command except that the refid is displayed in hex format and the association number is also displayed. associations Display a list of mobilized associations in the form:
Column    Description lstint    Interval in seconds between the receipt of the most recent packet from this address and the completion of the retrieval of the MRU list by ntpq. avgint    Average interval in s between packets from this address. rstr      Restriction flags associated with this address.  Most are copied unchanged from the matching restrict command, however 0x400 (kod) and 0x20 (limited) flags are cleared unless the last packet from this address triggered a rate control response. r         Rate control indicator, either a period, L or K for no rate control response, rate limiting by discarding, or rate limiting with a KoD response, respectively. m         Packet mode. v         Packet version number. count     Packets received from this address. rport     Source port of last packet from this address. remote address host or DNS name, numeric address, or address followed by claimed DNS name which could not be verified in parentheses. opeers [-4 | -6] Obtain and print the old-style list of all peers and clients showing dstadr (associated with the given IP version), rather than the refid. passociations Perform the same function as the associations command, except that it uses previously stored data rather than making a new query. peers     Display a list of peers in the form:
Status Words and Kiss Codes The current state of the operating program is shown in a set of status words maintained by the system.  Status information is also available on a per-association basis.  These words are displayed by the readlist and associations commands both in hexadecimal and in decoded short tip strings.  The codes, tips and short explanations are documented on the page.  The page also includes a list of system and peer messages, the code for the latest of which is included in the status word.
Information resulting from protocol machine state transitions is displayed using an informal set of ASCII strings called The original purpose was for kiss-o'-death (KoD) packets sent by the server to advise the client of an unusual condition.  They are now displayed, when appropriate, in the reference identifier field in various billboards.
System Variables The following system variables appear in the readlist billboard.  Not all variables are displayed in some configurations.
Variable  Description status version   NTP software version and build time processor hardware platform and version system    operating system and version leap      leap warning indicator (0-3) stratum   stratum (1-15) precision precision (log2 s) rootdelay total roundtrip delay to the primary reference clock rootdisp  total dispersion to the primary reference clock refid     reference id or reftime   reference time clock     date and time of day peer      system peer association id tc        time constant and poll exponent (log2 s) (3-17) mintc     minimum time constant (log2 s) (3-10) offset    combined offset of server relative to this host frequency frequency drift (PPM) relative to hardware clock sys_jitter combined system jitter clk_wander clock frequency wander (PPM) clk_jitter clock jitter tai       TAI-UTC offset (s) leapsec   NTP seconds when the next leap second is/was inserted expire    NTP seconds when the NIST leapseconds file expires
The jitter and wander statistics are exponentially-weighted RMS averages. The system jitter is defined in the NTPv4 specification; the clock jitter statistic is computed by the clock discipline module.
When the NTPv4 daemon is compiled with the OpenSSL software library, additional system variables are displayed, including some or all of the following, depending on the particular Autokey dance:
Variable  Description host      Autokey host name for this host ident     Autokey group name for this host flags     host flags  (see Autokey specification) digest    OpenSSL message digest algorithm signature OpenSSL digest/signature scheme update    NTP seconds at last signature update cert      certificate subject, issuer and certificate flags until     NTP seconds when the certificate expires
Peer Variables The following peer variables appear in the readlist billboard for each association.  Not all variables are displayed in some configurations.
Variable  Description associd   association id status srcadr    source (remote) IP address srcport   source (remote) port dstadr    destination (local) IP address dstport   destination (local) port leap      leap indicator (0-3) stratum   stratum (0-15) precision precision (log2 s) rootdelay total roundtrip delay to the primary reference clock rootdisp  total root dispersion to the primary reference clock refid     reference id or reftime   reference time rec       last packet received time reach     reach register (octal) unreach   unreach counter hmode     host mode (1-6) pmode     peer mode (1-5) hpoll     host poll exponent (log2 s) (3-17) ppoll     peer poll exponent (log2 s) (3-17) headway   headway (see flash keyid     symmetric key id offset    filter offset delay     filter delay dispersion filter dispersion jitter    filter jitter bias      unicast/broadcast bias xleave    interleave delay (see
The bias variable is calculated when the first broadcast packet is received after the calibration volley.  It represents the offset of the broadcast subgraph relative to the unicast subgraph.  The xleave variable appears only for the interleaved symmetric and interleaved modes.  It represents the internal queuing, buffering and transmission delays for the preceding packet.
When the NTPv4 daemon is compiled with the OpenSSL software library, additional peer variables are displayed, including the following:
Variable  Description flags     peer flags (see Autokey specification) host      Autokey server name flags     peer flags (see Autokey specification) signature OpenSSL digest/signature scheme initsequence initial key id initkey   initial key index timestamp Autokey signature timestamp ident     Autokey group name for this association
Clock Variables The following clock variables appear in the clocklist billboard for each association with a reference clock.  Not all variables are displayed in some configurations.
Variable  Description associd   association id status device    device description timecode  ASCII time code string (specific to device) poll      poll messages sent noreply   no reply badformat bad format baddata   bad date or time fudgetime1 fudge time 1 fudgetime2 fudge time 2 stratum   driver stratum refid     driver reference id flags     driver flags
-4, --ipv4 Force IPv4 name resolution.  This option must not appear in combination with any of the following options: ipv6.
Force resolution of following host names on the command line to the IPv4 namespace.
-6, --ipv6 Force IPv6 name resolution.  This option must not appear in combination with any of the following options: ipv4.
Force resolution of following host names on the command line to the IPv6 namespace.
-c cmd, --command=cmd run a command and exit.  This option may appear an unlimited number of times.
The following argument is interpreted as an interactive format command and is added to the list of commands to be executed on the specified host(s).
-d, --debug-level Increase debug verbosity level.  This option may appear an unlimited number of times.
-D number, --set-debug-level=number Set the debug verbosity level.  This option may appear an unlimited number of times.  This option takes an integer number as its argument.
-i, --interactive Force ntpq to operate in interactive mode.  This option must not appear in combination with any of the following options: command, peers.
Force ntpq to operate in interactive mode.  Prompts will be written to the standard output and commands read from the standard input.
-n, --numeric numeric host addresses.
Output all host addresses in dotted-quad numeric format rather than converting to the canonical host names.
--old-rv Always output status line with readvar.
By default, ntpq now suppresses the associd=...  line that precedes the output of readvar (alias rv) when a single variable is requested, such as ntpq -c "rv 0 offset".  This option causes ntpq to include both lines of output for a single-variable readvar.  Using an environment variable to preset this option in a script will enable both older and newer ntpq to behave identically in this regard.
-p, --peers Print a list of the peers.  This option must not appear in combination with any of the following options: interactive.
Print a list of the peers known to the server as well as a summary of their state. This is equivalent to the 'peers' interactive command.
-r keyword, --refid=keyword Set default display type for S2+ refids.  This option takes a keyword as its argument.  The argument sets an enumeration value that can be tested by comparing them against the option value macro.  The available keywords are: hash ipv4 or their numeric equivalent.
The default keyword for this option is: ipv4
Set the default display format for S2+ refids.
-w, --wide Display the full 'remote' value.
Display the full value of the 'remote' value.  If this requires more than 15 characters, display the full value, emit a newline, and continue the data display properly indented on the next line.
-?, --help Display usage information and exit.
-!, --more-help Pass the extended usage information through a pager.
-> [cfgfile], --save-opts [=cfgfile] Save the option state to cfgfile.  The default is the last configuration file listed in the OPTION PRESETS section, below. The command will exit after updating the config file.
-< cfgfile, --load-opts=cfgfile, --no-load-opts Load options from cfgfile.  The no-load-opts form will disable the loading of earlier config/rc/ini files.  --no-load-opts is handled early, out of order.
--version [{v|c|n}] Output version of program and exit.  The default mode is `v', a simple version.  The `c' mode will print copyright information and `n' will print the full copyright notice.
Any option that is not marked as not presettable may be preset by loading values from configuration ("RC" or ".INI") file(s) and values from environment variables named: NTPQ_<option-name> or NTPQ The environmental presets take precedence (are processed later than) the configuration files.  The homerc files are "$HOME", and ".".  If any of these are directories, then the file .ntprc is searched for within those directories.
See OPTION PRESETS for configuration environment variables.
See OPTION PRESETS for configuration files.
One of the following exit values will be returned:
0  (EXIT_SUCCESS) Successful program execution.
1  (EXIT_FAILURE) The operation failed or the command syntax was not valid.
66  (EX_NOINPUT) A specified configuration file could not be loaded.
70  (EX_SOFTWARE) libopts had an internal operational error.  Please report it to autogen-users@lists.sourceforge.net.  Thank you.
The University of Delaware and Network Time Foundation
Copyright (C) 1992-2020 The University of Delaware and Network Time Foundation all rights reserved.  This program is released under the terms of the NTP license, <http://ntp.org/license>.
Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
This manual page was AutoGen-erated from the ntpq option definitions.
LMMS(1)                      General Commands Manual                     LMMS(1)
lmms - software for easy music production
lmms [global options...] [action [action parameters...]]
LMMS is a free cross-platform alternative to commercial programs like FL StudioÂ®, which allow you to produce music with your computer. This includes the creation of melodies and beats, the synthesis and mixing of sounds, and arranging of samples. You can have fun with your MIDI- keyboard and much more; all in a user-friendly and modern interface.
LMMS features components such as a Song Editor, a Beat+Bassline Editor, a Piano Roll, an FX Mixer as well as many powerful instruments and effects.
<no action> [options...] [project] Start LMMS in normal GUI mode.
dump in Dump XML of compressed (MMPZ) file in.
render project [options...] Render given project file.
rendertracks project [options...] Render each track to a different file.
upgrade in [out] Upgrade file in and save as out. Standard out is used if no output file is specifed.
--allowroot Bypass root user startup check (use with caution).
-c, --config configfile Get the configuration from configfile instead of ~/.lmmsrc.xml (default).
-v, --version Show version information and exit.
--geometry geometry Specify the prefered size and position of the main window. geometry syntax is xsizexysize+xoffset+yoffset. Default: full screen.
--import in -e Import MIDI or Hydrogen file in.
-a, --float Use 32bit float bit depth.
-b, --bitrate bitrate Specify output bitrate in KBit/s (for OGG encoding only), default is 160.
-f, --format format Specify format of render-output where format is either 'wav', 'ogg' or 'mp3'.
-i, --interpolation method Specify interpolation method - possible values are linear, sincfastest (default), sincmedium, sincbest.
If -e is specified lmms exits after importing the file.
-l, --loop Render the given file as a loop, i.e. stop rendering at exactly the end of the song. Additional silence or reverb tails at the end of the song are not rendered.
-m, --mode stereomode Set the stereo mode used for the MP3 export. stereomode can be either 's' (stereo mode), 'j' (joint stereo) or 'm' (mono). If no mode is given 'j' is used as the default.
-o, --output path Render into path. For --render, this is interpreted as a file path. For --render-tracks, this is interpreted as a path to an existing directory.
-p, --profile out Dump profiling information to file out.
-s, --samplerate samplerate Specify output samplerate in Hz - range is 44100 (default) to 192000.
-x, --oversampling value Specify oversampling, possible values: 1, 2 (default), 4, 8.
https://lmms.io/ https://lmms.io/documentation/ https://github.com/LMMS/lmms
Tobias Doerffel <tobydox/at/users.sourceforge.net>, Paul Giblock and others. See AUTHORS for details.
LN(1P)                      POSIX Programmer's Manual                     LN(1P)
ln — link files
ln [-fs] [-L|-P] source_file... target_dir
In the first synopsis form, the ln utility shall create a new directory entry (link) at the destination path specified by the target_file operand. If the -s option is specified, a symbolic link shall be created for the file specified by the source_file operand. This first synopsis form shall be assumed when the final operand does not name an existing directory; if more than two operands are specified and the final is not an existing directory, an error shall result.
In the second synopsis form, the ln utility shall create a new directory entry (link), or if the -s option is specified a symbolic link, for each file specified by a source_file operand, at a destination path in the existing directory named by target_dir.
If the last operand specifies an existing file of a type not specified by the System Interfaces volume of POSIX.1‐2017, the behavior is implementation-defined.
The corresponding destination path for each source_file shall be the concatenation of the target directory pathname, a <slash> character if the target directory pathname did not end in a <slash>, and the last pathname component of the source_file.  The second synopsis form shall be assumed when the final operand names an existing directory.
For each source_file:
1. If the destination path exists and was created by a previous step, it is unspecified whether ln shall write a diagnostic message to standard error, do nothing more with the current source_file, and go on to any remaining source_files; or will continue processing the current source_file.  If the destination path exists:
a. If the -f option is not specified, ln shall write a diagnostic message to standard error, do nothing more with the current source_file, and go on to any remaining source_files.
b. If the destination path names the same directory entry as the current source_file ln shall write a diagnostic message to standard error, do nothing more with the current source_file, and go on to any remaining source_files.
c. Actions shall be performed equivalent to the unlink() function defined in the System Interfaces volume of POSIX.1‐2017, called using the destination path as the path argument. If this fails for any reason, ln shall write a diagnostic message to standard error, do nothing more with the current source_file, and go on to any remaining source_files.
2. If the -s option is specified, actions shall be performed equivalent to the symlink() function with source_file as the path1 argument and the destination path as the path2 argument. The ln utility shall do nothing more with source_file and shall go on to any remaining files.
3. If source_file is a symbolic link:
a. If the -P option is in effect, actions shall be performed equivalent to the linkat() function with source_file as the path1 argument, the destination path as the path2 argument, AT_FDCWD as the fd1 and fd2 arguments, and zero as the flag argument.
b. If the -L option is in effect, actions shall be performed equivalent to the linkat() function with source_file as the path1 argument, the destination path as the path2 argument, AT_FDCWD as the fd1 and fd2 arguments, and AT_SYMLINK_FOLLOW as the flag argument.
The ln utility shall do nothing more with source_file and shall go on to any remaining files.
4. Actions shall be performed equivalent to the link() function defined in the System Interfaces volume of POSIX.1‐2017 using source_file as the path1 argument, and the destination path as the path2 argument.
The ln utility shall conform to the Base Definitions volume of POSIX.1‐2017, Section 12.2, Utility Syntax Guidelines.
-f        Force existing destination pathnames to be removed to allow the link.
-L        For each source_file operand that names a file of type symbolic link, create a (hard) link to the file referenced by the symbolic link.
-P        For each source_file operand that names a file of type symbolic link, create a (hard) link to the symbolic link itself.
-s        Create symbolic links instead of hard links. If the -s option is specified, the -L and -P options shall be silently ignored.
Specifying more than one of the mutually-exclusive options -L and -P shall not be considered an error. The last option specified shall determine the behavior of the utility (unless the -s option causes it to be ignored).
If the -s option is not specified and neither a -L nor a -P option is specified, it is implementation-defined which of the -L and -P options will be used as the default.
source_file A pathname of a file to be linked. If the -s option is specified, no restrictions on the type of file or on its existence shall be made. If the -s option is not specified, whether a directory can be linked is implementation-defined.
target_file The pathname of the new directory entry to be created.
target_dir A pathname of an existing directory in which the new directory entries are created.
The following environment variables shall affect the execution of ln:
0    All the specified files were linked successfully.
The CONSEQUENCES OF ERRORS section does not require ln -f a b to remove b if a subsequent link operation would fail.
Some historic versions of ln (including the one specified by the SVID) unlink the destination file, if it exists, by default. If the mode does not permit writing, these versions prompt for confirmation before attempting the unlink. In these versions the -f option causes ln not to attempt to prompt for confirmation.
This allows ln to succeed in creating links when the target file already exists, even if the file itself is not writable (although the directory must be).  Early proposals specified this functionality.
This volume of POSIX.1‐2017 does not allow the ln utility to unlink existing destination paths by default for the following reasons:
*  The ln utility has historically been used to provide locking for shell applications, a usage that is incompatible with ln unlinking the destination path by default. There was no corresponding technical advantage to adding this functionality.
*  This functionality gave ln the ability to destroy the link structure of files, which changes the historical behavior of ln.
*  This functionality is easily replicated with a combination of rm and ln.
*  It is not historical practice in many systems; BSD and BSD-derived systems do not support this behavior. Unfortunately, whichever behavior is selected can cause scripts written expecting the other behavior to fail.
*  It is preferable that ln perform in the same manner as the link() function, which does not permit the target to exist already.
This volume of POSIX.1‐2017 retains the -f option to provide support for shell scripts depending on the SVID semantics. It seems likely that shell scripts would not be written to handle prompting by ln and would therefore have specified the -f option.
The -f option is an undocumented feature of many historical versions of the ln utility, allowing linking to directories. These versions require modification.
Early proposals of this volume of POSIX.1‐2017 also required a -i option, which behaved like the -i options in cp and mv, prompting for confirmation before unlinking existing files. This was not historical practice for the ln utility and has been omitted.
The -L and -P options allow for implementing both common behaviors of the ln utility. Earlier versions of this standard did not specify these options and required the behavior now described for the -L option. Many systems by default or as an alternative provided a non-conforming ln utility with the behavior now described for the -P option. Since applications could not rely on ln following links in practice, the -L and -P options were added to specify the desired behavior for the application.
The -L and -P options are ignored when -s is specified in order to allow an alias to be created to alter the default behavior when creating hard links (for example, alias ln='ln -L').  They serve no purpose when -s is specified, since source_file is then just a string to be used as the contents of the created symbolic link and need not exist as a file.
The specification ensures that ln a a with or without the -f option will not unlink the file a.  Earlier versions of this standard were unclear in this case.
chmod, find, pax, rm
The System Interfaces volume of POSIX.1‐2017, link(), unlink()
GENFSTAB(1)                                                          GENFSTAB(1)
genfstab - script to generate an fstab file based on mounted partitions
genfstab [options] root
-f FILTER Restrict output to mountpoints matching the prefix FILTER
-L Use labels for source identifiers (shortcut for -t LABEL)
-p Exclude pseudofs mounts (default behavior)
-P Include pseudofs mounts
-t TAG Use TAG for source identifiers. Common options for TAG include: LABEL, UUID, PARTLABEL, PARTUUID
-U Use UUIDs for source identifiers (shortcut for -t UUID)
One can use genfstab to generate fstab entries for mounted partitions given a filesystem root. This can be useful when installing or chrooting into a broken installation.
To generate an fstab file using UUIDs as identifiers, run:
genfstab -U /media/testing >> /media/testing/etc/fstab
pdfimages(1)                 General Commands Manual                pdfimages(1)
pdfimages - Portable Document Format (PDF) image extractor (version 3.03)
pdfimages [options] PDF-file image-root
Pdfimages saves images from a Portable Document Format (PDF) file as Portable Pixmap (PPM), Portable Bitmap (PBM), Portable Network Graphics (PNG), Tagged Image File Format (TIFF), JPEG, JPEG2000, or JBIG2 files.
Pdfimages reads the PDF file PDF-file, scans one or more pages, and writes one file for each image, image-root-nnn.xxx, where nnn is the image number and xxx is the image type (.ppm, .pbm, .png, .tif, .jpg, jp2, jb2e, or jb2g).  If PDF-file is Â´-', it reads the PDF file from stdin.
The default output format is PBM (for monochrome images) or PPM for non- monochrome. The -png or -tiff options change to default output to PNG or TIFF respectively. If both -png and -tiff are specified, CMYK images will be written as TIFF and all other images will be written as PNG. In addition the -j, -jp2, and -jbig2 options will cause JPEG, JPEG2000, and JBIG2, respectively, images in the PDF file to be written in their native format.
-f number Specifies the first page to scan.
-l number Specifies the last page to scan.
-png   Change the default output format to PNG.
-tiff  Change the default output format to TIFF.
-j     Write images in JPEG format as JPEG files instead of the default format. The JPEG file is identical to the JPEG data stored in the PDF.
-jp2   Write images in JPEG2000 format as JP2 files instead of the default format. The JP2 file is identical to the JPEG2000 data stored in the PDF.
-jbig2 Write images in JBIG2 format as JBIG2 files instead of the default format. JBIG2 data in PDF is of the embedded type. The embedded type of JBIG2 has an optional separate file containing global data. The embedded data is written with the extension .jb2e and the global data (if available) will be written to the same image number with the extension .jb2g. The content of both these files is identical to the JBIG2 data in the PDF.
-ccitt Write images in CCITT format as CCITT files instead of the default format. The CCITT file is identical to the CCITT data stored in the PDF. PDF files contain additional parameters specifying how to decode the CCITT data. These parameters are translated to fax2tiff input options and written to a .params file with the same image number. The parameters are:
-1     1D Group 3 encoding
-2     2D Group 3 encoding
-4     Group 4 encoding
-A     Beginning of line is aligned on a byte boundary
-P     Beginning of line is not aligned on a byte boundary
-X n   The image width in pixels
-W     Encoding uses 1 for black and 0 for white
-B     Encoding uses 0 for black and 1 for white
-M     Input data fills from most significant bit to least significant bit.
-all   Write JPEG, JPEG2000, JBIG2, and CCITT images in their native format. CMYK files are written as TIFF files. All other images are written as PNG files.  This is equivalent to specifying the options -png -tiff -j -jp2 -jbig2 -ccitt.
-list  Instead of writing the images, list the images along with various information for each image. Do not specify an image-root with this option.
The following information is listed for each image:
page   the page number containing the image
num    the image number
type   the image type:
image - an opaque image mask - a monochrome mask image smask - a soft-mask image stencil - a monochrome mask image used for painting a color or pattern
Note: Tranparency in images is represented in PDF using a separate image for the image and the mask/smask.  The mask/smask used as part of a transparent image always immediately follows the image in the image list.
width  image width (in pixels)
height image height (in pixels)
Note: the image width/height is the size of the embedded image, not the size the image will be rendered at.
color  image color space:
gray - Gray rgb - RGB cmyk - CMYK lab - L*a*b icc - ICC Based index - Indexed Color sep - Separation devn - DeviceN
comp   number of color components
bpc    bits per component
enc    encoding:
image - raster image (may be Flate or LZW compressed but does not use an image encoding) jpeg - Joint Photographic Experts Group jp2 - JPEG2000 jbig2 - Joint Bi-Level Image Experts Group ccitt - CCITT Group 3 or Group 4 Fax
interp "yes" if the interpolation is to be performed when scaling up the image
object ID the image dictionary object ID (number and generation)
x-ppi  The horizontal resolution of the image (in pixels per inch) when rendered on the pdf page.
y-ppi  The vertical resolution of the image (in pixels per inch) when rendered on the pdf page.
size   The size of the embedded image in the pdf file. The following suffixes are used: 'B' bytes, 'K' kilobytes, 'M' megabytes, and 'G' gigabytes.
ratio  The compression ratio of the embedded image.
-p     Include page numbers in output file names.
The pdfimages software and documentation are copyright 1998-2011 Glyph & Cog, LLC.
pdfdetach(1), pdffonts(1), pdfinfo(1), pdftocairo(1), pdftohtml(1), pdftoppm(1), pdftops(1), pdftotext(1) pdfseparate(1), pdfsig(1), pdfunite(1)
enca(1)                                                                  enca(1)
enca -- detect and convert encoding of text files
enca [-L LANGUAGE] [OPTION]... [FILE]... enconv [-L LANGUAGE] [OPTION]... [FILE]...
If you are lucky enough, the only two things you will ever need to know are: command
enca FILE
will tell you which encoding file FILE uses (without changing it), and
enconv FILE
will convert file FILE to your locale native encoding.  To convert the file to some other encoding use the -x option (see -x entry in section OPTIONS and sections CONVERSION and ENCODINGS for details).
Both work with multiple files and standard input (output) too.  E.g.
enca -x latin2 <sometext | lpr
assures file `sometext' is in ISO Latin 2 when it's sent to printer.
The main reason why these command will fail and turn your files into garbage is that Enca needs to know their language to detect the encoding. It tries to determine your language and preferred charset from locale settings, which might not be what you want.
You can (or have to) use -L option to tell it the right language. Suppose, you downloaded some Russian HTML file, `file.htm', it claims it's windows-1251 but it isn't.  So you run
enca -L ru file.htm
and find out it's KOI8-R (for example).  Be warned, currently there are not many supported languages (see section LANGUAGES).
Another warning concerns the fact several Enca's features, namely its charset conversion capabilities, strongly depend on what other tools are installed on your system (see section CONVERSION)--run
enca --version
to get list of features (see section FEATURES).  Also try
enca --help
to get description of all other Enca options (and to find the rest of this manual page redundant).
Enca reads given text files, or standard input when none are given, and uses knowledge about their language (must be supported by you) and a mixture of parsing, statistical analysis, guessing and black magic to determine their encodings, which it then prints to standard output (or it confesses it doesn't have any idea what the encoding could be).  By default, Enca presents results as a multiline human-readable descriptions, several other formats are available--see Output type selectors below.
Enca can also convert files to some other encoding ENC when you ask for it--either using a built-in converter, some conversion library, or by calling an external converter.
Enca's primary goal is to be usable unattended, as an automatic conversion tool, though it perhaps have not reached this point yet (please see section SECURITY).
Please note except rare cases Enca really has to know the language of input files to give you a reliable answer.  On the other hand, it can then cope quite well with files that are not purely textual or even detect charset of text strings inside some binary file; of course, it depends on the character of the non-text component.
Enca doesn't care about structure of input files, it views them as a uniform piece of text/data.  In case of multipart files (e.g. mailboxes), you have to use some tool knowing the structure to extract the individual parts first.  It's the cost of ability to detect encodings of any damaged, incomplete or otherwise incorrect files.
There are several categories of options: operation mode options, output type selectors, guessing parameters, conversion parameters, general options and listings.
All long options can be abbreviated as long as they are unambiguous, mandatory parameters of long options are mandatory for short options too.
Operation modes are following:
-c, --auto-convert Equivalent to calling Enca as enconv.
If no output type selector is specified, detect file encodings, guess your preferred charset from locales, and convert files to it (only available with +target-charset-auto feature).
-g, --guess Equivalent to calling Enca as enca.
If no output type selector is specified, detect file encodings and report them.
Output type selectors select what action Enca will take when it determines the encoding; most of them just choose between different names, formats and conventions how encodings can be printed, but one of them (-x) is special: it tells Enca to recode files to some other encoding ENC.  These options are mutually exclusive; if you specify more than one output type selector the last one takes precedence.
Several output types represent charset name used by some other program, but not all these programs know all the charsets which Enca recognises. Be warned, Enca makes no difference between unrecognised charset and charset having no name in given namespace in such situations.
-d, --details It used to print a few pages of details about the guessing process, but since Enca is just a program linked against Enca library, this is not possible and this option is roughly equivalent to --human-readable, except it reports failure reason when Enca doesn't recognize the encoding.
-e, --enca-name Prints Enca's nice name of the charset, i.e., perhaps the most generally accepted and more or less human-readable charset identifier, with surfaces appended.
This name is used when calling an external converter, too.
-f, --human-readable Prints verbal description of the detected charset and surfaces--something a human understands best.  This is the default behaviour.
The precise format is following: the first line contains charset name alone, and it's followed by zero or more indented lines containing names of detected surfaces.  This format is not, however, suitable or intended for further machine-processing, and the verbal charset descriptions are like to change in the future.
-i, --iconv-name Prints how iconv(3) (and/or iconv(1)) calls the detected charset. More precisely, it prints one, more or less arbitrarily chosen, alias accepted by iconv.  A charset unknown to iconv counts as unknown.
This output type makes sense only when Enca is compiled with iconv support (feature +iconv-interface).
-r, --rfc1345-name Prints RFC 1345 charset name.  When such a name doesn't exist because RFC 1345 doesn't define a given encoding, some other name defined in some other RFC or just the name which author considers `the most canonical', is printed.
Since RFC 1345 doesn't define surfaces, no surface info is appended.
-m, --mime-name Prints preferred MIME name of detected charset.  This is the name you should normally use when fixing e-mails or web pages.
A charset not present in http://www.iana.org/assignments/character-sets counts as unknown.
-s, --cstocs-name Prints how cstocs(1) calls the detected charset.  A charset unknown to cstocs counts as unknown.
-n, --name=WORD Prints charset (encoding) name selected by WORD (can be abbreviated as long as is unambiguous).  For names listed above, --name=WORD is equivalent to --WORD.
Using aliases as the output type causes Enca to print list of all accepted aliases of detected charset.
-x, --convert-to=[..]ENC Converts file to encoding ENC.
The optional `..' before encoding name has no special meaning, except you can use it to remind yourself that, unlike in recode(1), you should specify desired encoding, instead of current.
You can use recode(1) recoding chains or any other kind of braindead recoding specification for ENC, provided that you tell Enca to use some tool understanding it for conversion (see section CONVERSION).
When Enca fails to determine the encoding, it prints a warning and leaves the the file as is; when it is run as a filter it tries to do its best to copy standard input to standard output unchanged. Nevertheless, you should not rely on it and do backup.
Guessing parameters There's only one: -L setting language of input files. This option is mandatory (but see below).
-L, --language=LANG Sets language of input files to LANG.
More precisely, LANG can be any valid locale name (or alias with +locale-alias feature) of some supported language.  You can also specify `none' as language name, only multibyte encodings are recognised then.  Run
enca --list languages
to get list of supported languages.  When you don't specify any language Enca tries to guess your language from locale settings and assumes input files use this language.  See section LANGUAGES for details.
Conversion parameters give you finer control of how charset conversion will be performed.  They don't affect anything when -x is not specified as output type.  Please see section CONVERSION for the gory conversion details.
-C, --try-converters=LIST Appends comma separated LIST to the list of converters that will be tried when you ask for conversion.  Their names can be abbreviated as long as they are unambiguous.  Run
enca --list converters
to get list of all valid converter names (and see section CONVERSION for their description).
The default list depends on how Enca has been compiled, run
to find out default converter list.
Note the default list is used only when you don't specify -C at all.  Otherwise, the list is built as if it were initially empty and every -C adds new converter(s) to it.  Moreover, specifying none as converter name causes clearing the converter list.