linux command


Linux Command – man ใช้ในการแสดงคู่มือการใช้งาน program



man <command>

$ man logname
LOGNAME(1) User Commands LOGNAME(1)

 logname - print user´s login name

 logname [OPTION]

 Print the name of the current user.

 --help display this help and exit

 output version information and exit

 Written by FIXME: unknown.

 GNU coreutils online help: <>
 Report logname translation bugs to <>

 Copyright © 2016 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <>.
 This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.

 Full documentation at: <>
 or available locally via: info '(coreutils) logname invocation'

GNU coreutils 8.25 February 2016 LOGNAME(1)



 man [-C file] [-d] [-D] [--warnings[=warnings]] [-R encoding] [-L locale] [-m system[,...]] [-M path] [-S list] [-e extension] [-i|-I] [--regex|--wildcard] [--names-only] [-a] [-u]
 [--no-subpages] [-P pager] [-r prompt] [-7] [-E encoding] [--no-hyphenation] [--no-justification] [-p string] [-t] [-T[device]] [-H[browser]] [-X[dpi]] [-Z] [[section]
 page ...] ...
 man -k [apropos options] regexp ...
 man -K [-w|-W] [-S list] [-i|-I] [--regex] [section] term ...
 man -f [whatis options] page ...
 man -l [-C file] [-d] [-D] [--warnings[=warnings]] [-R encoding] [-L locale] [-P pager] [-r prompt] [-7] [-E encoding] [-p string] [-t] [-T[device]] [-H[browser]] [-X[dpi]] [-Z]
 file ...
 man -w|-W [-C file] [-d] [-D] page ...
 man -c [-C file] [-d] [-D] page ...
 man [-?V]



เป็นคำสั่งที่ใช้ในการแสดงคู่มือการใช้งาน program ย่อมาจาก manual



 General options
 -C file, --config-file=file
 Use this user configuration file rather than the default of ~/.manpath.

 -d, --debug
 Print debugging information.

 -D, --default
 This option is normally issued as the very first option and resets man's behaviour to its default. Its use is to reset those options that may have been set in $MANOPT. Any
 options that follow -D will have their usual effect.

 Enable warnings from groff. This may be used to perform sanity checks on the source text of manual pages. warnings is a comma-separated list of warning names; if it is not
 supplied, the default is "mac". See the “Warnings” node in info groff for a list of available warning names.

 Main modes of operation
 -f, --whatis
 Equivalent to whatis. Display a short description from the manual page, if available. See whatis(1) for details.

 -k, --apropos
 Equivalent to apropos. Search the short manual page descriptions for keywords and display any matches. See apropos(1) for details.

 -K, --global-apropos
 Search for text in all manual pages. This is a brute-force search, and is likely to take some time; if you can, you should specify a section to reduce the number of pages
 that need to be searched. Search terms may be simple strings (the default), or regular expressions if the --regex option is used.

 -l, --local-file
 Activate `local' mode. Format and display local manual files instead of searching through the system's manual collection. Each manual page argument will be interpreted as
 an nroff source file in the correct format. No cat file is produced. If '-' is listed as one of the arguments, input will be taken from stdin. When this option is not
 used, and man fails to find the page required, before displaying the error message, it attempts to act as if this option was supplied, using the name as a filename and look‐
 ing for an exact match.

 -w, --where, --path, --location
 Don't actually display the manual pages, but do print the location(s) of the source nroff files that would be formatted.

 -W, --where-cat, --location-cat
 Don't actually display the manual pages, but do print the location(s) of the cat files that would be displayed. If -w and -W are both specified, print both separated by a

 -c, --catman
 This option is not for general use and should only be used by the catman program.

 -R encoding, --recode=encoding
 Instead of formatting the manual page in the usual way, output its source converted to the specified encoding. If you already know the encoding of the source file, you can
 also use manconv(1) directly. However, this option allows you to convert several manual pages to a single encoding without having to explicitly state the encoding of each,
 provided that they were already installed in a structure similar to a manual page hierarchy.

 Finding manual pages
 -L locale, --locale=locale
 man will normally determine your current locale by a call to the C function setlocale(3) which interrogates various environment variables, possibly including $LC_MESSAGES
 and $LANG. To temporarily override the determined value, use this option to supply a locale string directly to man. Note that it will not take effect until the search for
 pages actually begins. Output such as the help message will always be displayed in the initially determined locale.

 -m system[,...], --systems=system[,...]
 If this system has access to other operating system's manual pages, they can be accessed using this option. To search for a manual page from NewOS's manual page collection,
 use the option -m NewOS.

 The system specified can be a combination of comma delimited operating system names. To include a search of the native operating system's manual pages, include the system
 name man in the argument string. This option will override the $SYSTEM environment variable.

 -M path, --manpath=path
 Specify an alternate manpath to use. By default, man uses manpath derived code to determine the path to search. This option overrides the $MANPATH environment variable and
 causes option -m to be ignored.

 A path specified as a manpath must be the root of a manual page hierarchy structured into sections as described in the man-db manual (under "The manual page system"). To
 view manual pages outside such hierarchies, see the -l option.

 -S list, -s list, --sections=list
 List is a colon- or comma-separated list of `order specific' manual sections to search. This option overrides the $MANSECT environment variable. (The -s spelling is for
 compatibility with System V.)

 -e sub-extension, --extension=sub-extension
 Some systems incorporate large packages of manual pages, such as those that accompany the Tcl package, into the main manual page hierarchy. To get around the problem of
 having two manual pages with the same name such as exit(3), the Tcl pages were usually all assigned to section l. As this is unfortunate, it is now possible to put the
 pages in the correct section, and to assign a specific `extension' to them, in this case, exit(3tcl). Under normal operation, man will display exit(3) in preference to
 exit(3tcl). To negotiate this situation and to avoid having to know which section the page you require resides in, it is now possible to give man a sub-extension string
 indicating which package the page must belong to. Using the above example, supplying the option -e tcl to man will restrict the search to pages having an extension of *tcl.

 -i, --ignore-case
 Ignore case when searching for manual pages. This is the default.

 -I, --match-case
 Search for manual pages case-sensitively.

 Show all pages with any part of either their names or their descriptions matching each page argument as a regular expression, as with apropos(1). Since there is usually no
 reasonable way to pick a "best" page when searching for a regular expression, this option implies -a.

 Show all pages with any part of either their names or their descriptions matching each page argument using shell-style wildcards, as with apropos(1) --wildcard. The page
 argument must match the entire name or description, or match on word boundaries in the description. Since there is usually no reasonable way to pick a "best" page when
 searching for a wildcard, this option implies -a.

 If the --regex or --wildcard option is used, match only page names, not page descriptions, as with whatis(1). Otherwise, no effect.

 -a, --all
 By default, man will exit after displaying the most suitable manual page it finds. Using this option forces man to display all the manual pages with names that match the
 search criteria.

 -u, --update
 This option causes man to perform an `inode level' consistency check on its database caches to ensure that they are an accurate representation of the filesystem. It will
 only have a useful effect if man is installed with the setuid bit set.

 By default, man will try to interpret pairs of manual page names given on the command line as equivalent to a single manual page name containing a hyphen or an underscore.
 This supports the common pattern of programs that implement a number of subcommands, allowing them to provide manual pages for each that can be accessed using similar syntax
 as would be used to invoke the subcommands themselves. For example:

 $ man -aw git diff

 To disable this behaviour, use the --no-subpages option.

 $ man -aw --no-subpages git diff

 Controlling formatted output
 -P pager, --pager=pager
 Specify which output pager to use. By default, man uses pager. This option overrides the $MANPAGER environment variable, which in turn overrides the $PAGER environment
 variable. It is not used in conjunction with -f or -k.

 The value may be a simple command name or a command with arguments, and may use shell quoting (backslashes, single quotes, or double quotes). It may not use pipes to con‐
 nect multiple commands; if you need that, use a wrapper script, which may take the file to display either as an argument or on standard input.

 -r prompt, --prompt=prompt
 If a recent version of less is used as the pager, man will attempt to set its prompt and some sensible options. The default prompt looks like

 Manual page name(sec) line x

 where name denotes the manual page name, sec denotes the section it was found under and x the current line number. This is achieved by using the $LESS environment variable.

 Supplying -r with a string will override this default. The string may contain the text $MAN_PN which will be expanded to the name of the current manual page and its section
 name surrounded by `(' and `)'. The string used to produce the default could be expressed as

 \ Manual\ page\ \$MAN_PN\ ?ltline\ %lt?L/%L.:
 byte\ %bB?s/%s..?\ (END):?pB\ %pB\\%..
 (press h for help or q to quit)

 It is broken into three lines here for the sake of readability only. For its meaning see the less(1) manual page. The prompt string is first evaluated by the shell. All
 double quotes, back-quotes and backslashes in the prompt must be escaped by a preceding backslash. The prompt string may end in an escaped $ which may be followed by fur‐
 ther options for less. By default man sets the -ix8 options.

 The $MANLESS environment variable described below may be used to set a default prompt string if none is supplied on the command line.

 -7, --ascii
 When viewing a pure ascii(7) manual page on a 7 bit terminal or terminal emulator, some characters may not display correctly when using the latin1(7) device description with
 GNU nroff. This option allows pure ascii manual pages to be displayed in ascii with the latin1 device. It will not translate any latin1 text. The following table shows
 the translations performed: some parts of it may only be displayed properly when using GNU nroff's latin1(7) device.

 Description Octal latin1 ascii
 continuation hyphen 255 ‐ -
 bullet (middle dot) 267 · o
 acute accent 264 ´ '
 multiplication sign 327 × x

 If the latin1 column displays correctly, your terminal may be set up for latin1 characters and this option is not necessary. If the latin1 and ascii columns are identical,
 you are reading this page using this option or man did not format this page using the latin1 device description. If the latin1 column is missing or corrupt, you may need to
 view manual pages with this option.

 This option is ignored when using options -t, -H, -T, or -Z and may be useless for nroff other than GNU's.

 -E encoding, --encoding=encoding
 Generate output for a character encoding other than the default. For backward compatibility, encoding may be an nroff device such as ascii, latin1, or utf8 as well as a
 true character encoding such as UTF-8.

 --no-hyphenation, --nh
 Normally, nroff will automatically hyphenate text at line breaks even in words that do not contain hyphens, if it is necessary to do so to lay out words on a line without
 excessive spacing. This option disables automatic hyphenation, so words will only be hyphenated if they already contain hyphens.

 If you are writing a manual page and simply want to prevent nroff from hyphenating a word at an inappropriate point, do not use this option, but consult the nroff documenta‐
 tion instead; for instance, you can put "\%" inside a word to indicate that it may be hyphenated at that point, or put "\%" at the start of a word to prevent it from being

 --no-justification, --nj
 Normally, nroff will automatically justify text to both margins. This option disables full justification, leaving justified only to the left margin, sometimes called
 "ragged-right" text.

 If you are writing a manual page and simply want to prevent nroff from justifying certain paragraphs, do not use this option, but consult the nroff documentation instead;
 for instance, you can use the ".na", ".nf", ".fi", and ".ad" requests to temporarily disable adjusting and filling.

 -p string, --preprocessor=string
 Specify the sequence of preprocessors to run before nroff or troff/groff. Not all installations will have a full set of preprocessors. Some of the preprocessors and the
 letters used to designate them are: eqn (e), grap (g), pic (p), tbl (t), vgrind (v), refer (r). This option overrides the $MANROFFSEQ environment variable. zsoelim is
 always run as the very first preprocessor.

 -t, --troff
 Use groff -mandoc to format the manual page to stdout. This option is not required in conjunction with -H, -T, or -Z.

 -T[device], --troff-device[=device]
 This option is used to change groff (or possibly troff's) output to be suitable for a device other than the default. It implies -t. Examples (provided with Groff-1.17)
 include dvi, latin1, ps, utf8, X75 and X100.

 -H[browser], --html[=browser]
 This option will cause groff to produce HTML output, and will display that output in a web browser. The choice of browser is determined by the optional browser argument if
 one is provided, by the $BROWSER environment variable, or by a compile-time default if that is unset (usually lynx). This option implies -t, and will only work with GNU

 -X[dpi], --gxditview[=dpi]
 This option displays the output of groff in a graphical window using the gxditview program. The dpi (dots per inch) may be 75, 75-12, 100, or 100-12, defaulting to 75; the
 -12 variants use a 12-point base font. This option implies -T with the X75, X75-12, X100, or X100-12 device respectively.

 -Z, --ditroff
 groff will run troff and then use an appropriate post-processor to produce output suitable for the chosen device. If groff -mandoc is groff, this option is passed to groff
 and will suppress the use of a post-processor. It implies -t.

 Getting help
 -?, --help
 Print a help message and exit.

 Print a short usage message and exit.

 -V, --version
 Display version information.



apropos(1), groff(1), less(1), manpath(1), nroff(1), troff(1), whatis(1), zsoelim(1), setlocale(3), manpath(5), ascii(7), latin1(7), man(7), catman(8), mandb(8), the man-db packagemanual, FSSTND



คำสั่ง Unix – Linux Command

Linux, Unix


Author: Suphakit Annoppornchai


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