{ "content": [ { "type": "text", "text": "# man (info)\n\n## NAME\n\nman - an interface to the system reference manuals\n\n## SYNOPSIS\n\nman [man options] [[section] page ...] ...\nman -k [apropos options] regexp ...\nman -K [man options] [section] term ...\nman -f [whatis options] page ...\nman -l [man options] file ...\nman -w|-W [man options] page ...\n\n## DESCRIPTION\n\nThis manual page explains the groff an.tmac macro package (often called\nthe man macro package). This macro package should be used by develop-\ners when writing or porting man pages for Linux. It is fairly compati-\nble with other versions of this macro package, so porting man pages\nshould not be a major problem (exceptions include the NET-2 BSD re-\nlease, which uses a totally different macro package called mdoc; see\nmdoc(7)).\n\n## Sections\n\n- **NAME**\n- **SYNOPSIS**\n- **DESCRIPTION**\n- **EXAMPLES**\n- **OVERVIEW**\n- **DEFAULTS**\n- **OPTIONS** (27 subsections)\n- **EXIT STATUS**\n- **ENVIRONMENT**\n- **FILES**\n- **SEE ALSO**\n- **HISTORY**\n- **BUGS**\n- **NOTES**\n- **COLOPHON**\n\nUse structuredContent.sections for detailed options, examples, and full documentation.\n" } ], "structuredContent": { "command": "man", "section": "", "mode": "info", "summary": "man - an interface to the system reference manuals", "synopsis": "man [man options] [[section] page ...] ...\nman -k [apropos options] regexp ...\nman -K [man options] [section] term ...\nman -f [whatis options] page ...\nman -l [man options] file ...\nman -w|-W [man options] page ...", "tldr_summary": null, "tldr_examples": [], "tldr_source": null, "flags": [ { "flag": "-d", "long": "--debug", "arg": null, "description": "Print debugging information." }, { "flag": "-D", "long": "--default", "arg": null, "description": "This option is normally issued as the very first option and re- sets 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." }, { "flag": "", "long": null, "arg": null, "description": "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 de- fault is \"mac\". See the \"Warnings\" node in info groff for a list of available warning names. Main modes of operation" }, { "flag": "-f", "long": "--whatis", "arg": null, "description": "Equivalent to whatis. Display a short description from the man- ual page, if available. See whatis(1) for details." }, { "flag": "-k", "long": "--apropos", "arg": null, "description": "Equivalent to apropos. Search the short manual page descrip- tions for keywords and display any matches. See apropos(1) for details." }, { "flag": "-K", "long": "--global-apropos", "arg": null, "description": "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. Note that this searches the sources of the manual pages, not the rendered text, and so may include false positives due to things like comments in source files. Searching the rendered text would be much slower." }, { "flag": "-l", "long": "--local-file", "arg": null, "description": "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 re- quired, before displaying the error message, it attempts to act as if this option was supplied, using the name as a filename and looking for an exact match." }, { "flag": "-w", "long": "--location", "arg": null, "description": "Don't actually display the manual page, but do print the loca- tion of the source nroff file that would be formatted. If the -a option is also used, then print the locations of all source files that match the search criteria." }, { "flag": "-W", "long": "--location-cat", "arg": null, "description": "Don't actually display the manual page, but do print the loca- tion of the preformatted cat file that would be displayed. If the -a option is also used, then print the locations of all pre- formatted cat files that match the search criteria. If -w and -W are both used, then print both source file and cat file separated by a space. If all of -w, -W, and -a are used, then do this for each possible match." }, { "flag": "-c", "long": "--catman", "arg": null, "description": "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 man- conv(1) directly. However, this option allows you to convert several manual pages to a single encoding without having to ex- plicitly state the encoding of each, provided that they were al- ready installed in a structure similar to a manual page hierar- chy. Consider using man-recode(1) instead for converting multiple manual pages, since it has an interface designed for bulk con- version and so can be much faster. 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 $LCMESSAGES and $LANG. To tempo- rarily override the determined value, use this option to supply a locale string directly to man. Note that it will not take ef- fect until the search for pages actually begins. Output such as the help message will always be displayed in the initially de- termined locale. -m system[,...], --systems=system[,...] If this system has access to other operating systems' 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 op- erating system names. To include a search of the native operat- ing system's manual pages, include the system name man in the argument string. This option will override the $SYSTEM environ- ment variable. -M path, --manpath=path Specify an alternate manpath to use. By default, man uses man- path 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 The given list is a colon- or comma-separated list of sections, used to determine which manual sections to search and in what order. 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, sup- plying the option -e tcl to man will restrict the search to pages having an extension of *tcl." }, { "flag": "-i", "long": "--ignore-case", "arg": null, "description": "Ignore case when searching for manual pages. This is the de- fault." }, { "flag": "-I", "long": "--match-case", "arg": null, "description": "Search for manual pages case-sensitively." }, { "flag": "", "long": "--regex", "arg": null, "description": "Show all pages with any part of either their names or their de- scriptions 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." }, { "flag": "", "long": "--wildcard", "arg": null, "description": "Show all pages with any part of either their names or their de- scriptions matching each page argument using shell-style wild- cards, as with apropos(1) --wildcard. The page argument must match the entire name or description, or match on word bound- aries in the description. Since there is usually no reasonable way to pick a \"best\" page when searching for a wildcard, this option implies -a." }, { "flag": "", "long": "--names-only", "arg": null, "description": "If the --regex or --wildcard option is used, match only page names, not page descriptions, as with whatis(1). Otherwise, no effect." }, { "flag": "-a", "long": "--all", "arg": null, "description": "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." }, { "flag": "-u", "long": "--update", "arg": null, "description": "This option causes man to update its database caches of in- stalled manual pages. This is only needed in rare situations, and it is normally better to run mandb(8) instead." }, { "flag": "", "long": "--no-subpages", "arg": null, "description": "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 subcom- mands, 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 /usr/share/man/man1/git-diff.1.gz To disable this behaviour, use the --no-subpages option. $ man -aw --no-subpages git diff /usr/share/man/man1/git.1.gz /usr/share/man/man3/Git.3pm.gz /usr/share/man/man1/diff.1.gz Controlling formatted output -P pager, --pager=pager Specify which output pager to use. By default, man uses pager, falling back to cat if pager is not found or is not executable. 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 argu- ments, and may use shell quoting (backslashes, single quotes, or double quotes). It may not use pipes to connect multiple com- mands; 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 at- tempt 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 $MANPN which will be expanded to the name of the current manual page and its section name sur- rounded by \"(\" and \")\". The string used to produce the default could be expressed as \\ Manual\\ page\\ \\$MANPN\\ ?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 further 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. continuation hy- 255 - - phen bullet (middle 267 o o dot) acute accent 264 ' ' multiplication 327 x x sign 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 us- ing 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." }, { "flag": "", "long": "--nh", "arg": null, "description": "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 documentation 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 hyphenated." }, { "flag": "", "long": "--nj", "arg": null, "description": "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 op- tion, but consult the nroff documentation instead; for instance, you can use the \".na\", \".nf\", \".fi\", and \".ad\" requests to tem- porarily 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 pre- processors. 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 environ- ment variable. zsoelim is always run as the very first pre- processor." }, { "flag": "-t", "long": "--troff", "arg": null, "description": "Use groff -mandoc to format the manual page to stdout. This op- tion is not required in conjunction with -H, -T, or -Z." }, { "flag": "", "long": null, "arg": null, "description": "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." }, { "flag": "", "long": null, "arg": null, "description": "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 de- fault if that is unset (usually lynx). This option implies -t, and will only work with GNU troff." }, { "flag": "", "long": null, "arg": null, "description": "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." }, { "flag": "-Z", "long": "--ditroff", "arg": null, "description": "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 sup- press the use of a post-processor. It implies -t. Getting help -?, --help Print a help message and exit." }, { "flag": "", "long": "--usage", "arg": null, "description": "Print a short usage message and exit." }, { "flag": "-V", "long": "--version", "arg": null, "description": "Display version information." } ], "examples": [ "man ls", "Display the manual page for the item (program) ls.", "man man.7", "Display the manual page for macro package man from section 7.", "(This is an alternative spelling of \"man 7 man\".)", "man 'man(7)'", "Display the manual page for macro package man from section 7.", "(This is another alternative spelling of \"man 7 man\". It may be", "more convenient when copying and pasting cross-references to manual", "pages. Note that the parentheses must normally be quoted to pro-", "tect them from the shell.)", "man -a intro", "Display, in succession, all of the available intro manual pages", "contained within the manual. It is possible to quit between suc-", "cessive displays or skip any of them.", "man -t bash | lpr -Pps", "Format the manual page for bash into the default troff or groff", "format and pipe it to the printer named ps. The default output for", "groff is usually PostScript. man --help should advise as to which", "processor is bound to the -t option.", "man -l -Tdvi ./foo.1x.gz > ./foo.1x.dvi", "This command will decompress and format the nroff source manual", "page ./foo.1x.gz into a device independent (dvi) file. The redi-", "rection is necessary as the -T flag causes output to be directed to", "stdout with no pager. The output could be viewed with a program", "such as xdvi or further processed into PostScript using a program", "such as dvips.", "man -k printf", "Search the short descriptions and manual page names for the keyword", "printf as regular expression. Print out any matches. Equivalent", "to apropos printf.", "man -f smail", "Lookup the manual pages referenced by smail and print out the short", "descriptions of any found. Equivalent to whatis smail." ], "see_also": [ { "name": "apropos", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/apropos/1/json" }, { "name": "groff", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/groff/1/json" }, { "name": "less", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/less/1/json" }, { "name": "manpath", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/manpath/1/json" }, { "name": "nroff", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/nroff/1/json" }, { "name": "troff", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/troff/1/json" }, { "name": "whatis", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/whatis/1/json" }, { "name": "zsoelim", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/zsoelim/1/json" }, { "name": "manpath", "section": "5", "url": "https://www.chedong.com/phpMan.php/man/manpath/5/json" }, { "name": "catman", "section": "8", "url": "https://www.chedong.com/phpMan.php/man/catman/8/json" }, { "name": "mandb", "section": "8", "url": "https://www.chedong.com/phpMan.php/man/mandb/8/json" }, { "name": "info", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/info/1/json" } ], "section_outline": [ { "name": "NAME", "lines": 2, "subsections": [] }, { "name": "SYNOPSIS", "lines": 6, "subsections": [] }, { "name": "DESCRIPTION", "lines": 213, "subsections": [] }, { "name": "EXAMPLES", "lines": 42, "subsections": [] }, { "name": "OVERVIEW", "lines": 45, "subsections": [] }, { "name": "DEFAULTS", "lines": 31, "subsections": [] }, { "name": "OPTIONS", "lines": 9, "subsections": [ { "name": "-d, --debug", "lines": 2, "flag": "-d", "long": "--debug" }, { "name": "-D, --default", "lines": 5, "flag": "-D", "long": "--default" }, { "name": "--warnings[=warnings]", "lines": 7 }, { "name": "-f, --whatis", "lines": 3, "flag": "-f", "long": "--whatis" }, { "name": "-k, --apropos", "lines": 4, "flag": "-k", "long": "--apropos" }, { "name": "-K, --global-apropos", "lines": 11, "flag": "-K", "long": "--global-apropos" }, { "name": "-l, --local-file", "lines": 10, "flag": "-l", "long": "--local-file" }, { "name": "-w, --where, --path, --location", "lines": 5, "flag": "-w", "long": "--location" }, { "name": "-W, --where-cat, --location-cat", "lines": 9, "flag": "-W", "long": "--location-cat" }, { "name": "-c, --catman", "lines": 73, "flag": "-c", "long": "--catman" }, { "name": "-i, --ignore-case", "lines": 3, "flag": "-i", "long": "--ignore-case" }, { "name": "-I, --match-case", "lines": 2, "flag": "-I", "long": "--match-case" }, { "name": "--regex", "lines": 6, "long": "--regex" }, { "name": "--wildcard", "lines": 8, "long": "--wildcard" }, { "name": "--names-only", "lines": 4, "long": "--names-only" }, { "name": "-a, --all", "lines": 4, "flag": "-a", "long": "--all" }, { "name": "-u, --update", "lines": 4, "flag": "-u", "long": "--update" }, { "name": "--no-subpages", "lines": 100, "long": "--no-subpages" }, { "name": "--no-hyphenation, --nh", "lines": 13, "long": "--nh" }, { "name": "--no-justification, --nj", "lines": 19, "long": "--nj" }, { "name": "-t, --troff", "lines": 3, "flag": "-t", "long": "--troff" }, { "name": "-T[device], --troff-device[=device]", "lines": 5 }, { "name": "-H[browser], --html[=browser]", "lines": 7 }, { "name": "-X[dpi], --gxditview[=dpi]", "lines": 6 }, { "name": "-Z, --ditroff", "lines": 9, "flag": "-Z", "long": "--ditroff" }, { "name": "--usage", "lines": 2, "long": "--usage" }, { "name": "-V, --version", "lines": 2, "flag": "-V", "long": "--version" } ] }, { "name": "EXIT STATUS", "lines": 11, "subsections": [] }, { "name": "ENVIRONMENT", "lines": 113, "subsections": [] }, { "name": "FILES", "lines": 3, "subsections": [] }, { "name": "SEE ALSO", "lines": 3, "subsections": [] }, { "name": "HISTORY", "lines": 16, "subsections": [] }, { "name": "BUGS", "lines": 11, "subsections": [] }, { "name": "NOTES", "lines": 34, "subsections": [] }, { "name": "COLOPHON", "lines": 6, "subsections": [] } ], "sections": { "NAME": { "content": "man - macros to format man pages\n", "subsections": [] }, "SYNOPSIS": { "content": "groff -Tascii -man file ...\n\ngroff -Tps -man file ...\n\nman [section] title\n", "subsections": [] }, "DESCRIPTION": { "content": "This manual page explains the groff an.tmac macro package (often called\nthe man macro package). This macro package should be used by develop-\ners when writing or porting man pages for Linux. It is fairly compati-\nble with other versions of this macro package, so porting man pages\nshould not be a major problem (exceptions include the NET-2 BSD re-\nlease, which uses a totally different macro package called mdoc; see\nmdoc(7)).\n\nNote that NET-2 BSD mdoc man pages can be used with groff simply by\nspecifying the -mdoc option instead of the -man option. Using the\n-mandoc option is, however, recommended, since this will automatically\ndetect which macro package is in use.\n\nFor conventions that should be employed when writing man pages for the\nLinux man-pages package, see man-pages(7).\n\nTitle line\nThe first command in a man page (after comment lines, that is, lines\nthat start with .\\\") should be\n\n.TH title section date source manual\n\nFor details of the arguments that should be supplied to the TH command,\nsee man-pages(7).\n\nNote that BSD mdoc-formatted pages begin with the Dd command, not the\nTH command.\n\nSections\nSections are started with .SH followed by the heading name.\n\nThe only mandatory heading is NAME, which should be the first section\nand be followed on the next line by a one-line description of the pro-\ngram:\n\n.SH NAME\nitem \\- description\n\nIt is extremely important that this format is followed, and that there\nis a backslash before the single dash which follows the item name.\nThis syntax is used by the mandb(8) program to create a database of\nshort descriptions for the whatis(1) and apropos(1) commands. (See\nlexgrog(1) for further details on the syntax of the NAME section.)\n\nFor a list of other sections that might appear in a manual page, see\nman-pages(7).\n\nFonts\nThe commands to select the type face are:\n\n.B Bold\n\n.BI Bold alternating with italics (especially useful for function spec-\nifications)\n\n.BR Bold alternating with Roman (especially useful for referring to\nother manual pages)\n\n.I Italics\n\n.IB Italics alternating with bold\n\n.IR Italics alternating with Roman\n\n.RB Roman alternating with bold\n\n.RI Roman alternating with italics\n\n.SB Small alternating with bold\n\n.SM Small (useful for acronyms)\n\nTraditionally, each command can have up to six arguments, but the GNU\nimplementation removes this limitation (you might still want to limit\nyourself to 6 arguments for portability's sake). Arguments are delim-\nited by spaces. Double quotes can be used to specify an argument which\ncontains spaces. For the macros that produce alternating type faces,\nthe arguments will be printed next to each other without intervening\nspaces, so that the .BR command can be used to specify a word in bold\nfollowed by a mark of punctuation in Roman. If no arguments are given,\nthe command is applied to the following line of text.\n\nOther macros and strings\nBelow are other relevant macros and predefined strings. Unless noted\notherwise, all macros cause a break (end the current line of text).\nMany of these macros set or use the \"prevailing indent.\" The \"prevail-\ning indent\" value is set by any macro with the parameter i below;\nmacros may omit i in which case the current prevailing indent will be\nused. As a result, successive indented paragraphs can use the same in-\ndent without respecifying the indent value. A normal (nonindented)\nparagraph resets the prevailing indent value to its default value (0.5\ninches). By default, a given indent is measured in ens; try to use ens\nor ems as units for indents, since these will automatically adjust to\nfont size changes. The other key macro definitions are:\n\nNormal paragraphs\n.LP Same as .PP (begin a new paragraph).\n\n.P Same as .PP (begin a new paragraph).\n\n.PP Begin a new paragraph and reset prevailing indent.\n\nRelative margin indent\n.RS i Start relative margin indent: moves the left margin i to the\nright (if i is omitted, the prevailing indent value is used).\nA new prevailing indent is set to 0.5 inches. As a result,\nall following paragraph(s) will be indented until the corre-\nsponding .RE.\n\n.RE End relative margin indent and restores the previous value of\nthe prevailing indent.\n\nIndented paragraph macros\n.HP i Begin paragraph with a hanging indent (the first line of the\nparagraph is at the left margin of normal paragraphs, and the\nrest of the paragraph's lines are indented).\n\n.IP x i Indented paragraph with optional hanging tag. If the tag x is\nomitted, the entire following paragraph is indented by i. If\nthe tag x is provided, it is hung at the left margin before\nthe following indented paragraph (this is just like .TP except\nthe tag is included with the command instead of being on the\nfollowing line). If the tag is too long, the text after the\ntag will be moved down to the next line (text will not be lost\nor garbled). For bulleted lists, use this macro with \\(bu\n(bullet) or \\(em (em dash) as the tag, and for numbered lists,\nuse the number or letter followed by a period as the tag; this\nsimplifies translation to other formats.\n\n.TP i Begin paragraph with hanging tag. The tag is given on the\nnext line, but its results are like those of the .IP command.\n\nHypertext link macros\n.UR url\nInsert a hypertext link to the URI (URL) url, with all text up\nto the following .UE macro as the link text.\n\n.UE [trailer]\nTerminate the link text of the preceding .UR macro, with the op-\ntional trailer (if present, usually a closing parenthesis and/or\nend-of-sentence punctuation) immediately following. For non-\nHTML output devices (e.g., man -Tutf8), the link text is fol-\nlowed by the URL in angle brackets; if there is no link text,\nthe URL is printed as its own link text, surrounded by angle\nbrackets. (Angle brackets may not be available on all output\ndevices.) For the HTML output device, the link text is hyper-\nlinked to the URL; if there is no link text, the URL is printed\nas its own link text.\n\nThese macros have been supported since GNU Troff 1.20 (2009-01-05) and\nHeirloom Doctools Troff since 160217 (2016-02-17).\n\nMiscellaneous macros\n.DT Reset tabs to default tab values (every 0.5 inches); does not\ncause a break.\n\n.PD d Set inter-paragraph vertical distance to d (if omitted,\nd=0.4v); does not cause a break.\n\n.SS t Subheading t (like .SH, but used for a subsection inside a\nsection).\n\nPredefined strings\nThe man package has the following predefined strings:\n\n\\*R Registration Symbol: (R)\n\n\\*S Change to default font size\n\n\\*(Tm Trademark Symbol: tm\n\n\\*(lq Left angled double quote: \"\n\n\\*(rq Right angled double quote: \"\n\nSafe subset\nAlthough technically man is a troff macro package, in reality a large\nnumber of other tools process man page files that don't implement all\nof troff's abilities. Thus, it's best to avoid some of troff's more\nexotic abilities where possible to permit these other tools to work\ncorrectly. Avoid using the various troff preprocessors (if you must,\ngo ahead and use tbl(1), but try to use the IP and TP commands instead\nfor two-column tables). Avoid using computations; most other tools\ncan't process them. Use simple commands that are easy to translate to\nother formats. The following troff macros are believed to be safe\n(though in many cases they will be ignored by translators): \\\", ., ad,\nbp, br, ce, de, ds, el, ie, if, fi, ft, hy, ig, in, na, ne, nf, nh, ps,\nso, sp, ti, tr.\n\nYou may also use many troff escape sequences (those sequences beginning\nwith \\). When you need to include the backslash character as normal\ntext, use \\e. Other sequences you may use, where x or xx are any char-\nacters and N is any digit, include: \\', \\`, \\-, \\., \\\", \\%, \\*x, \\*(xx,\n\\(xx, \\$N, \\nx, \\n(xx, \\fx, and \\f(xx. Avoid using the escape se-\nquences for drawing graphics.\n\nDo not use the optional parameter for bp (break page). Use only posi-\ntive values for sp (vertical space). Don't define a macro (de) with\nthe same name as a macro in this or the mdoc macro package with a dif-\nferent meaning; it's likely that such redefinitions will be ignored.\nEvery positive indent (in) should be paired with a matching negative\nindent (although you should be using the RS and RE macros instead).\nThe condition test (if,ie) should only have 't' or 'n' as the condi-\ntion. Only translations (tr) that can be ignored should be used. Font\nchanges (ft and the \\f escape sequence) should only have the values 1,\n2, 3, 4, R, I, B, P, or CW (the ft command may also have no parame-\nters).\n\nIf you use capabilities beyond these, check the results carefully on\nseveral tools. Once you've confirmed that the additional capability is\nsafe, let the maintainer of this document know about the safe command\nor sequence that should be added to this list.\n", "subsections": [] }, "EXAMPLES": { "content": "man ls\nDisplay the manual page for the item (program) ls.\n\nman man.7\nDisplay the manual page for macro package man from section 7.\n(This is an alternative spelling of \"man 7 man\".)\n\nman 'man(7)'\nDisplay the manual page for macro package man from section 7.\n(This is another alternative spelling of \"man 7 man\". It may be\nmore convenient when copying and pasting cross-references to manual\npages. Note that the parentheses must normally be quoted to pro-\ntect them from the shell.)\n\nman -a intro\nDisplay, in succession, all of the available intro manual pages\ncontained within the manual. It is possible to quit between suc-\ncessive displays or skip any of them.\n\nman -t bash | lpr -Pps\nFormat the manual page for bash into the default troff or groff\nformat and pipe it to the printer named ps. The default output for\ngroff is usually PostScript. man --help should advise as to which\nprocessor is bound to the -t option.\n\nman -l -Tdvi ./foo.1x.gz > ./foo.1x.dvi\nThis command will decompress and format the nroff source manual\npage ./foo.1x.gz into a device independent (dvi) file. The redi-\nrection is necessary as the -T flag causes output to be directed to\nstdout with no pager. The output could be viewed with a program\nsuch as xdvi or further processed into PostScript using a program\nsuch as dvips.\n\nman -k printf\nSearch the short descriptions and manual page names for the keyword\nprintf as regular expression. Print out any matches. Equivalent\nto apropos printf.\n\nman -f smail\nLookup the manual pages referenced by smail and print out the short\ndescriptions of any found. Equivalent to whatis smail.\n", "subsections": [] }, "OVERVIEW": { "content": "Many options are available to man in order to give as much flexibility\nas possible to the user. Changes can be made to the search path, sec-\ntion order, output processor, and other behaviours and operations de-\ntailed below.\n\nIf set, various environment variables are interrogated to determine the\noperation of man. It is possible to set the \"catch-all\" variable\n$MANOPT to any string in command line format, with the exception that\nany spaces used as part of an option's argument must be escaped (pre-\nceded by a backslash). man will parse $MANOPT prior to parsing its own\ncommand line. Those options requiring an argument will be overridden\nby the same options found on the command line. To reset all of the op-\ntions set in $MANOPT, -D can be specified as the initial command line\noption. This will allow man to \"forget\" about the options specified in\n$MANOPT, although they must still have been valid.\n\nManual pages are normally stored in nroff(1) format under a directory\nsuch as /usr/share/man. In some installations, there may also be pre-\nformatted cat pages to improve performance. See manpath(5) for details\nof where these files are stored.\n\nThis package supports manual pages in multiple languages, controlled by\nyour locale. If your system did not set this up for you automatically,\nthen you may need to set $LCMESSAGES, $LANG, or another system-depen-\ndent environment variable to indicate your preferred locale, usually\nspecified in the POSIX format:\n\n[[.[,]]]\n\nIf the desired page is available in your locale, it will be displayed\nin lieu of the standard (usually American English) page.\n\nIf you find that the translations supplied with this package are not\navailable in your native language and you would like to supply them,\nplease contact the maintainer who will be coordinating such activity.\n\nIndividual manual pages are normally written and maintained by the\nmaintainers of the program, function, or other topic that they docu-\nment, and are not included with this package. If you find that a man-\nual page is missing or inadequate, please report that to the maintain-\ners of the package in question.\n\nFor information regarding other features and extensions available with\nthis manual pager, please read the documents supplied with the package.\n", "subsections": [] }, "DEFAULTS": { "content": "The order of sections to search may be overridden by the environment\nvariable $MANSECT or by the SECTION directive in /etc/manpath.config.\nBy default it is as follows:\n\n1 n l 8 3 0 2 3posix 3pm 3perl 3am 5 4 9 6 7\n\nThe formatted manual page is displayed using a pager. This can be\nspecified in a number of ways, or else will fall back to a default (see\noption -P for details).\n\nThe filters are deciphered by a number of means. Firstly, the command\nline option -p or the environment variable $MANROFFSEQ is interrogated.\nIf -p was not used and the environment variable was not set, the ini-\ntial line of the nroff file is parsed for a preprocessor string. To\ncontain a valid preprocessor string, the first line must resemble\n\n'\\\" \n\nwhere string can be any combination of letters described by option -p\nbelow.\n\nIf none of the above methods provide any filter information, a default\nset is used.\n\nA formatting pipeline is formed from the filters and the primary for-\nmatter (nroff or [tg]roff with -t) and executed. Alternatively, if an\nexecutable program mandbnfmt (or mandbtfmt with -t) exists in the man\ntree root, it is executed instead. It gets passed the manual source\nfile, the preprocessor string, and optionally the device specified with\n-T or -E as arguments.\n", "subsections": [] }, "OPTIONS": { "content": "Non-argument options that are duplicated either on the command line, in\n$MANOPT, or both, are not harmful. For options that require an argu-\nment, each duplication will override the previous argument value.\n\nGeneral options\n-C file, --config-file=file\nUse this user configuration file rather than the default of\n~/.manpath.\n", "subsections": [ { "name": "-d, --debug", "content": "Print debugging information.\n", "flag": "-d", "long": "--debug" }, { "name": "-D, --default", "content": "This option is normally issued as the very first option and re-\nsets man's behaviour to its default. Its use is to reset those\noptions that may have been set in $MANOPT. Any options that\nfollow -D will have their usual effect.\n", "flag": "-D", "long": "--default" }, { "name": "--warnings[=warnings]", "content": "Enable warnings from groff. This may be used to perform sanity\nchecks on the source text of manual pages. warnings is a comma-\nseparated list of warning names; if it is not supplied, the de-\nfault is \"mac\". See the \"Warnings\" node in info groff for a\nlist of available warning names.\n\nMain modes of operation" }, { "name": "-f, --whatis", "content": "Equivalent to whatis. Display a short description from the man-\nual page, if available. See whatis(1) for details.\n", "flag": "-f", "long": "--whatis" }, { "name": "-k, --apropos", "content": "Equivalent to apropos. Search the short manual page descrip-\ntions for keywords and display any matches. See apropos(1) for\ndetails.\n", "flag": "-k", "long": "--apropos" }, { "name": "-K, --global-apropos", "content": "Search for text in all manual pages. This is a brute-force\nsearch, and is likely to take some time; if you can, you should\nspecify a section to reduce the number of pages that need to be\nsearched. Search terms may be simple strings (the default), or\nregular expressions if the --regex option is used.\n\nNote that this searches the sources of the manual pages, not the\nrendered text, and so may include false positives due to things\nlike comments in source files. Searching the rendered text\nwould be much slower.\n", "flag": "-K", "long": "--global-apropos" }, { "name": "-l, --local-file", "content": "Activate \"local\" mode. Format and display local manual files\ninstead of searching through the system's manual collection.\nEach manual page argument will be interpreted as an nroff source\nfile in the correct format. No cat file is produced. If '-' is\nlisted as one of the arguments, input will be taken from stdin.\nWhen this option is not used, and man fails to find the page re-\nquired, before displaying the error message, it attempts to act\nas if this option was supplied, using the name as a filename and\nlooking for an exact match.\n", "flag": "-l", "long": "--local-file" }, { "name": "-w, --where, --path, --location", "content": "Don't actually display the manual page, but do print the loca-\ntion of the source nroff file that would be formatted. If the\n-a option is also used, then print the locations of all source\nfiles that match the search criteria.\n", "flag": "-w", "long": "--location" }, { "name": "-W, --where-cat, --location-cat", "content": "Don't actually display the manual page, but do print the loca-\ntion of the preformatted cat file that would be displayed. If\nthe -a option is also used, then print the locations of all pre-\nformatted cat files that match the search criteria.\n\nIf -w and -W are both used, then print both source file and cat\nfile separated by a space. If all of -w, -W, and -a are used,\nthen do this for each possible match.\n", "flag": "-W", "long": "--location-cat" }, { "name": "-c, --catman", "content": "This option is not for general use and should only be used by\nthe catman program.\n\n-R encoding, --recode=encoding\nInstead of formatting the manual page in the usual way, output\nits source converted to the specified encoding. If you already\nknow the encoding of the source file, you can also use man-\nconv(1) directly. However, this option allows you to convert\nseveral manual pages to a single encoding without having to ex-\nplicitly state the encoding of each, provided that they were al-\nready installed in a structure similar to a manual page hierar-\nchy.\n\nConsider using man-recode(1) instead for converting multiple\nmanual pages, since it has an interface designed for bulk con-\nversion and so can be much faster.\n\nFinding manual pages\n-L locale, --locale=locale\nman will normally determine your current locale by a call to the\nC function setlocale(3) which interrogates various environment\nvariables, possibly including $LCMESSAGES and $LANG. To tempo-\nrarily override the determined value, use this option to supply\na locale string directly to man. Note that it will not take ef-\nfect until the search for pages actually begins. Output such as\nthe help message will always be displayed in the initially de-\ntermined locale.\n\n-m system[,...], --systems=system[,...]\nIf this system has access to other operating systems' manual\npages, they can be accessed using this option. To search for a\nmanual page from NewOS's manual page collection, use the option\n-m NewOS.\n\nThe system specified can be a combination of comma delimited op-\nerating system names. To include a search of the native operat-\ning system's manual pages, include the system name man in the\nargument string. This option will override the $SYSTEM environ-\nment variable.\n\n-M path, --manpath=path\nSpecify an alternate manpath to use. By default, man uses man-\npath derived code to determine the path to search. This option\noverrides the $MANPATH environment variable and causes option -m\nto be ignored.\n\nA path specified as a manpath must be the root of a manual page\nhierarchy structured into sections as described in the man-db\nmanual (under \"The manual page system\"). To view manual pages\noutside such hierarchies, see the -l option.\n\n-S list, -s list, --sections=list\nThe given list is a colon- or comma-separated list of sections,\nused to determine which manual sections to search and in what\norder. This option overrides the $MANSECT environment variable.\n(The -s spelling is for compatibility with System V.)\n\n-e sub-extension, --extension=sub-extension\nSome systems incorporate large packages of manual pages, such as\nthose that accompany the Tcl package, into the main manual page\nhierarchy. To get around the problem of having two manual pages\nwith the same name such as exit(3), the Tcl pages were usually\nall assigned to section l. As this is unfortunate, it is now\npossible to put the pages in the correct section, and to assign\na specific \"extension\" to them, in this case, exit(3tcl). Under\nnormal operation, man will display exit(3) in preference to\nexit(3tcl). To negotiate this situation and to avoid having to\nknow which section the page you require resides in, it is now\npossible to give man a sub-extension string indicating which\npackage the page must belong to. Using the above example, sup-\nplying the option -e tcl to man will restrict the search to\npages having an extension of *tcl.\n", "flag": "-c", "long": "--catman" }, { "name": "-i, --ignore-case", "content": "Ignore case when searching for manual pages. This is the de-\nfault.\n", "flag": "-i", "long": "--ignore-case" }, { "name": "-I, --match-case", "content": "Search for manual pages case-sensitively.\n", "flag": "-I", "long": "--match-case" }, { "name": "--regex", "content": "Show all pages with any part of either their names or their de-\nscriptions matching each page argument as a regular expression,\nas with apropos(1). Since there is usually no reasonable way to\npick a \"best\" page when searching for a regular expression, this\noption implies -a.\n", "long": "--regex" }, { "name": "--wildcard", "content": "Show all pages with any part of either their names or their de-\nscriptions matching each page argument using shell-style wild-\ncards, as with apropos(1) --wildcard. The page argument must\nmatch the entire name or description, or match on word bound-\naries in the description. Since there is usually no reasonable\nway to pick a \"best\" page when searching for a wildcard, this\noption implies -a.\n", "long": "--wildcard" }, { "name": "--names-only", "content": "If the --regex or --wildcard option is used, match only page\nnames, not page descriptions, as with whatis(1). Otherwise, no\neffect.\n", "long": "--names-only" }, { "name": "-a, --all", "content": "By default, man will exit after displaying the most suitable\nmanual page it finds. Using this option forces man to display\nall the manual pages with names that match the search criteria.\n", "flag": "-a", "long": "--all" }, { "name": "-u, --update", "content": "This option causes man to update its database caches of in-\nstalled manual pages. This is only needed in rare situations,\nand it is normally better to run mandb(8) instead.\n", "flag": "-u", "long": "--update" }, { "name": "--no-subpages", "content": "By default, man will try to interpret pairs of manual page names\ngiven on the command line as equivalent to a single manual page\nname containing a hyphen or an underscore. This supports the\ncommon pattern of programs that implement a number of subcom-\nmands, allowing them to provide manual pages for each that can\nbe accessed using similar syntax as would be used to invoke the\nsubcommands themselves. For example:\n\n$ man -aw git diff\n/usr/share/man/man1/git-diff.1.gz\n\nTo disable this behaviour, use the --no-subpages option.\n\n$ man -aw --no-subpages git diff\n/usr/share/man/man1/git.1.gz\n/usr/share/man/man3/Git.3pm.gz\n/usr/share/man/man1/diff.1.gz\n\nControlling formatted output\n-P pager, --pager=pager\nSpecify which output pager to use. By default, man uses pager,\nfalling back to cat if pager is not found or is not executable.\nThis option overrides the $MANPAGER environment variable, which\nin turn overrides the $PAGER environment variable. It is not\nused in conjunction with -f or -k.\n\nThe value may be a simple command name or a command with argu-\nments, and may use shell quoting (backslashes, single quotes, or\ndouble quotes). It may not use pipes to connect multiple com-\nmands; if you need that, use a wrapper script, which may take\nthe file to display either as an argument or on standard input.\n\n-r prompt, --prompt=prompt\nIf a recent version of less is used as the pager, man will at-\ntempt to set its prompt and some sensible options. The default\nprompt looks like\n\nManual page name(sec) line x\n\nwhere name denotes the manual page name, sec denotes the section\nit was found under and x the current line number. This is\nachieved by using the $LESS environment variable.\n\nSupplying -r with a string will override this default. The\nstring may contain the text $MANPN which will be expanded to\nthe name of the current manual page and its section name sur-\nrounded by \"(\" and \")\". The string used to produce the default\ncould be expressed as\n\n\\ Manual\\ page\\ \\$MANPN\\ ?ltline\\ %lt?L/%L.:\nbyte\\ %bB?s/%s..?\\ (END):?pB\\ %pB\\\\%..\n(press h for help or q to quit)\n\nIt is broken into three lines here for the sake of readability\nonly. For its meaning see the less(1) manual page. The prompt\nstring is first evaluated by the shell. All double quotes,\nback-quotes and backslashes in the prompt must be escaped by a\npreceding backslash. The prompt string may end in an escaped $\nwhich may be followed by further options for less. By default\nman sets the -ix8 options.\n\nThe $MANLESS environment variable described below may be used to\nset a default prompt string if none is supplied on the command\nline.\n\n-7, --ascii\nWhen viewing a pure ascii(7) manual page on a 7 bit terminal or\nterminal emulator, some characters may not display correctly\nwhen using the latin1(7) device description with GNU nroff.\nThis option allows pure ascii manual pages to be displayed in\nascii with the latin1 device. It will not translate any latin1\ntext. The following table shows the translations performed:\nsome parts of it may only be displayed properly when using GNU\nnroff's latin1(7) device.\n\ncontinuation hy- 255 - -\nphen\nbullet (middle 267 o o\ndot)\nacute accent 264 ' '\nmultiplication 327 x x\nsign\n\nIf the latin1 column displays correctly, your terminal may be\nset up for latin1 characters and this option is not necessary.\nIf the latin1 and ascii columns are identical, you are reading\nthis page using this option or man did not format this page us-\ning the latin1 device description. If the latin1 column is\nmissing or corrupt, you may need to view manual pages with this\noption.\n\nThis option is ignored when using options -t, -H, -T, or -Z and\nmay be useless for nroff other than GNU's.\n\n-E encoding, --encoding=encoding\nGenerate output for a character encoding other than the default.\nFor backward compatibility, encoding may be an nroff device such\nas ascii, latin1, or utf8 as well as a true character encoding\nsuch as UTF-8.\n", "long": "--no-subpages" }, { "name": "--no-hyphenation, --nh", "content": "Normally, nroff will automatically hyphenate text at line breaks\neven in words that do not contain hyphens, if it is necessary to\ndo so to lay out words on a line without excessive spacing.\nThis option disables automatic hyphenation, so words will only\nbe hyphenated if they already contain hyphens.\n\nIf you are writing a manual page and simply want to prevent\nnroff from hyphenating a word at an inappropriate point, do not\nuse this option, but consult the nroff documentation instead;\nfor instance, you can put \"\\%\" inside a word to indicate that it\nmay be hyphenated at that point, or put \"\\%\" at the start of a\nword to prevent it from being hyphenated.\n", "long": "--nh" }, { "name": "--no-justification, --nj", "content": "Normally, nroff will automatically justify text to both margins.\nThis option disables full justification, leaving justified only\nto the left margin, sometimes called \"ragged-right\" text.\n\nIf you are writing a manual page and simply want to prevent\nnroff from justifying certain paragraphs, do not use this op-\ntion, but consult the nroff documentation instead; for instance,\nyou can use the \".na\", \".nf\", \".fi\", and \".ad\" requests to tem-\nporarily disable adjusting and filling.\n\n-p string, --preprocessor=string\nSpecify the sequence of preprocessors to run before nroff or\ntroff/groff. Not all installations will have a full set of pre-\nprocessors. Some of the preprocessors and the letters used to\ndesignate them are: eqn (e), grap (g), pic (p), tbl (t), vgrind\n(v), refer (r). This option overrides the $MANROFFSEQ environ-\nment variable. zsoelim is always run as the very first pre-\nprocessor.\n", "long": "--nj" }, { "name": "-t, --troff", "content": "Use groff -mandoc to format the manual page to stdout. This op-\ntion is not required in conjunction with -H, -T, or -Z.\n", "flag": "-t", "long": "--troff" }, { "name": "-T[device], --troff-device[=device]", "content": "This option is used to change groff (or possibly troff's) output\nto be suitable for a device other than the default. It implies\n-t. Examples (provided with Groff-1.17) include dvi, latin1,\nps, utf8, X75 and X100.\n" }, { "name": "-H[browser], --html[=browser]", "content": "This option will cause groff to produce HTML output, and will\ndisplay that output in a web browser. The choice of browser is\ndetermined by the optional browser argument if one is provided,\nby the $BROWSER environment variable, or by a compile-time de-\nfault if that is unset (usually lynx). This option implies -t,\nand will only work with GNU troff.\n" }, { "name": "-X[dpi], --gxditview[=dpi]", "content": "This option displays the output of groff in a graphical window\nusing the gxditview program. The dpi (dots per inch) may be 75,\n75-12, 100, or 100-12, defaulting to 75; the -12 variants use a\n12-point base font. This option implies -T with the X75,\nX75-12, X100, or X100-12 device respectively.\n" }, { "name": "-Z, --ditroff", "content": "groff will run troff and then use an appropriate post-processor\nto produce output suitable for the chosen device. If groff\n-mandoc is groff, this option is passed to groff and will sup-\npress the use of a post-processor. It implies -t.\n\nGetting help\n-?, --help\nPrint a help message and exit.\n", "flag": "-Z", "long": "--ditroff" }, { "name": "--usage", "content": "Print a short usage message and exit.\n", "long": "--usage" }, { "name": "-V, --version", "content": "Display version information.\n", "flag": "-V", "long": "--version" } ] }, "EXIT STATUS": { "content": "0 Successful program execution.\n\n1 Usage, syntax or configuration file error.\n\n2 Operational error.\n\n3 A child process returned a non-zero exit status.\n\n16 At least one of the pages/files/keywords didn't exist or wasn't\nmatched.\n", "subsections": [] }, "ENVIRONMENT": { "content": "MANPATH\nIf $MANPATH is set, its value is used as the path to search for\nmanual pages.\n\nSee the SEARCH PATH section of manpath(5) for the default behav-\niour and details of how this environment variable is handled.\n\nMANROFFOPT\nEvery time man invokes the formatter (nroff, troff, or groff),\nit adds the contents of $MANROFFOPT to the formatter's command\nline.\n\nMANROFFSEQ\nIf $MANROFFSEQ is set, its value is used to determine the set of\npreprocessors to pass each manual page through. The default\npreprocessor list is system dependent.\n\nMANSECT\nIf $MANSECT is set, its value is a colon-delimited list of sec-\ntions and it is used to determine which manual sections to\nsearch and in what order. The default is \"1 n l 8 3 0 2 3posix\n3pm 3perl 3am 5 4 9 6 7\", unless overridden by the SECTION di-\nrective in /etc/manpath.config.\n\nMANPAGER, PAGER\nIf $MANPAGER or $PAGER is set ($MANPAGER is used in preference),\nits value is used as the name of the program used to display the\nmanual page. By default, pager is used, falling back to cat if\npager is not found or is not executable.\n\nThe value may be a simple command name or a command with argu-\nments, and may use shell quoting (backslashes, single quotes, or\ndouble quotes). It may not use pipes to connect multiple com-\nmands; if you need that, use a wrapper script, which may take\nthe file to display either as an argument or on standard input.\n\nMANLESS\nIf $MANLESS is set, its value will be used as the default prompt\nstring for the less pager, as if it had been passed using the -r\noption (so any occurrences of the text $MANPN will be expanded\nin the same way). For example, if you want to set the prompt\nstring unconditionally to \"my prompt string\", set $MANLESS to\n'-Psmy prompt string'. Using the -r option overrides this envi-\nronment variable.\n\nBROWSER\nIf $BROWSER is set, its value is a colon-delimited list of com-\nmands, each of which in turn is used to try to start a web\nbrowser for man --html. In each command, %s is replaced by a\nfilename containing the HTML output from groff, %% is replaced\nby a single percent sign (%), and %c is replaced by a colon (:).\n\nSYSTEM If $SYSTEM is set, it will have the same effect as if it had\nbeen specified as the argument to the -m option.\n\nMANOPT If $MANOPT is set, it will be parsed prior to man's command line\nand is expected to be in a similar format. As all of the other\nman specific environment variables can be expressed as command\nline options, and are thus candidates for being included in\n$MANOPT it is expected that they will become obsolete. N.B.\nAll spaces that should be interpreted as part of an option's ar-\ngument must be escaped.\n\nMANWIDTH\nIf $MANWIDTH is set, its value is used as the line length for\nwhich manual pages should be formatted. If it is not set, man-\nual pages will be formatted with a line length appropriate to\nthe current terminal (using the value of $COLUMNS, and ioctl(2)\nif available, or falling back to 80 characters if neither is\navailable). Cat pages will only be saved when the default for-\nmatting can be used, that is when the terminal line length is\nbetween 66 and 80 characters.\n\nMANKEEPFORMATTING\nNormally, when output is not being directed to a terminal (such\nas to a file or a pipe), formatting characters are discarded to\nmake it easier to read the result without special tools. How-\never, if $MANKEEPFORMATTING is set to any non-empty value,\nthese formatting characters are retained. This may be useful\nfor wrappers around man that can interpret formatting charac-\nters.\n\nMANKEEPSTDERR\nNormally, when output is being directed to a terminal (usually\nto a pager), any error output from the command used to produce\nformatted versions of manual pages is discarded to avoid inter-\nfering with the pager's display. Programs such as groff often\nproduce relatively minor error messages about typographical\nproblems such as poor alignment, which are unsightly and gener-\nally confusing when displayed along with the manual page. How-\never, some users want to see them anyway, so, if\n$MANKEEPSTDERR is set to any non-empty value, error output\nwill be displayed as usual.\n\nMANDISABLESECCOMP\nOn Linux, man normally confines subprocesses that handle un-\ntrusted data using a seccomp(2) sandbox. This makes it safer to\nrun complex parsing code over arbitrary manual pages. If this\ngoes wrong for some reason unrelated to the content of the page\nbeing displayed, you can set $MANDISABLESECCOMP to any non-\nempty value to disable the sandbox.\n\nPIPELINEDEBUG\nIf the $PIPELINEDEBUG environment variable is set to \"1\", then\nman will print debugging messages to standard error describing\neach subprocess it runs.\n\nLANG, LCMESSAGES\nDepending on system and implementation, either or both of $LANG\nand $LCMESSAGES will be interrogated for the current message\nlocale. man will display its messages in that locale (if avail-\nable). See setlocale(3) for precise details.\n", "subsections": [] }, "FILES": { "content": "/usr/share/groff/[*/]tmac/an.tmac\n/usr/man/whatis\n", "subsections": [] }, "SEE ALSO": { "content": "apropos(1), groff(1), lexgrog(1), man(1), man2html(1), groffmdoc(7),\nwhatis(1), groffman(7), groffwww(7), man-pages(7), mdoc(7)\n", "subsections": [] }, "HISTORY": { "content": "1990, 1991 - Originally written by John W. Eaton (jwe@che.utexas.edu).\n\nDec 23 1992: Rik Faith (faith@cs.unc.edu) applied bug fixes supplied by\nWillem Kasdorp (wkasdo@nikhefk.nikef.nl).\n\n30th April 1994 - 23rd February 2000: Wilf. (G.Wilford@ee.surrey.ac.uk)\nhas been developing and maintaining this package with the help of a few\ndedicated people.\n\n30th October 1996 - 30th March 2001: Fabrizio Polacco maintained and enhanced this package for the Debian project,\nwith the help of all the community.\n\n31st March 2001 - present day: Colin Watson is\nnow developing and maintaining man-db.\n", "subsections": [] }, "BUGS": { "content": "Most of the macros describe formatting (e.g., font type and spacing)\ninstead of marking semantic content (e.g., this text is a reference to\nanother page), compared to formats like mdoc and DocBook (even HTML has\nmore semantic markings). This situation makes it harder to vary the\nman format for different media, to make the formatting consistent for a\ngiven media, and to automatically insert cross-references. By sticking\nto the safe subset described above, it should be easier to automate\ntransitioning to a different reference page format in the future.\n\nThe Sun macro TX is not implemented.\n", "subsections": [] }, "NOTES": { "content": "By all means include full URLs (or URIs) in the text itself; some tools\nsuch as man2html(1) can automatically turn them into hypertext links.\nYou can also use the UR and UE macros to identify links to related in-\nformation. If you include URLs, use the full URL (e.g.,\n) to ensure that tools can automatically find\nthe URLs.\n\nTools processing these files should open the file and examine the first\nnonwhitespace character. A period (.) or single quote (') at the be-\nginning of a line indicates a troff-based file (such as man or mdoc).\nA left angle bracket (<) indicates an SGML/XML-based file (such as HTML\nor Docbook). Anything else suggests simple ASCII text (e.g., a \"cat-\nman\" result).\n\nMany man pages begin with '\\\" followed by a space and a list of charac-\nters, indicating how the page is to be preprocessed. For portability's\nsake to non-troff translators we recommend that you avoid using any-\nthing other than tbl(1), and Linux can detect that automatically. How-\never, you might want to include this information so your man page can\nbe handled by other (less capable) systems. Here are the definitions\nof the preprocessors invoked by these characters:\n\ne eqn(1)\n\ng grap(1)\n\np pic(1)\n\nr refer(1)\n\nt tbl(1)\n\nv vgrind(1)\n", "subsections": [] }, "COLOPHON": { "content": "This page is part of release 5.10 of the Linux man-pages project. A\ndescription of the project, information about reporting bugs, and the\nlatest version of this page, can be found at\nhttps://www.kernel.org/doc/man-pages/.\n\nLinux 2020-11-01 MAN(7)", "subsections": [] } } } }