{
    "mode": "info",
    "parameter": "whatis",
    "section": "",
    "url": "https://www.chedong.com/phpMan.php/info/whatis/json",
    "generated": "2026-07-27T09:18:46Z",
    "synopsis": "whatis  [-dlv?V]  [-r|-w] [-s list] [-m system[,...]] [-M path] [-L lo-\ncale] [-C file] name ...",
    "sections": {
        "NAME": {
            "content": "whatis - display one-line manual page descriptions\n",
            "subsections": []
        },
        "SYNOPSIS": {
            "content": "whatis  [-dlv?V]  [-r|-w] [-s list] [-m system[,...]] [-M path] [-L lo-\ncale] [-C file] name ...\n",
            "subsections": []
        },
        "DESCRIPTION": {
            "content": "Each manual page has a short description available within  it.   whatis\nsearches  the  manual  page names and displays the manual page descrip-\ntions of any name matched.\n\nname may contain wildcards (-w) or be a regular expression (-r).  Using\nthese  options, it may be necessary to quote the name or escape (\\) the\nspecial characters to stop the shell from interpreting them.\n\nindex databases are used during the search,  and  are  updated  by  the\nmandb  program.   Depending  on your installation, this may be run by a\nperiodic cron job, or may need to be  run  manually  after  new  manual\npages  have  been installed.  To produce an old style text whatis data-\nbase from the relative index database, issue the command:\n\nwhatis -M manpath -w '*' | sort > manpath/whatis\n\nwhere manpath is a manual page hierarchy such as /usr/man.\n",
            "subsections": []
        },
        "OPTIONS": {
            "content": "",
            "subsections": [
                {
                    "name": "-d, --debug",
                    "content": "Print debugging information.\n",
                    "flag": "-d",
                    "long": "--debug"
                },
                {
                    "name": "-v, --verbose",
                    "content": "Print verbose warning messages.\n",
                    "flag": "-v",
                    "long": "--verbose"
                },
                {
                    "name": "-r, --regex",
                    "content": "Interpret each name as a regular expression.  If a name  matches\nany  part  of  a  page  name, a match will be made.  This option\ncauses whatis to be somewhat slower due to the nature  of  data-\nbase searches.\n",
                    "flag": "-r",
                    "long": "--regex"
                },
                {
                    "name": "-w, --wildcard",
                    "content": "Interpret  each  name  as a pattern containing shell style wild-\ncards.  For a match to be made, an expanded name must match  the\nentire  page  name.   This  option  causes whatis to be somewhat\nslower due to the nature of database searches.\n",
                    "flag": "-w",
                    "long": "--wildcard"
                },
                {
                    "name": "-l, --long",
                    "content": "Do not trim output to the terminal width.  Normally, output will\nbe  truncated  to  the terminal width to avoid ugly results from\npoorly-written NAME sections.\n\n-s list, --sections=list, --section=list\nSearch only the given manual sections.   list  is  a  colon-  or\ncomma-separated list of sections.  If an entry in list is a sim-\nple section, for example \"3\", then the  displayed  list  of  de-\nscriptions  will  include  pages in sections \"3\", \"3perl\", \"3x\",\nand so on; while if an entry in list has an extension, for exam-\nple \"3perl\", then the list will only include pages in that exact\npart of the manual section.\n\n-m system[,...], --systems=system[,...]\nIf this system has access to  other  operating  systems'  manual\npage  names,  they can be accessed using this option.  To search\nNewOS's manual page names, use the option -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 page names, include the system name  man  in\nthe  argument string.  This option will override the $SYSTEM en-\nvironment variable.\n\n-M path, --manpath=path\nSpecify an alternate set of colon-delimited manual page  hierar-\nchies  to search.  By default, whatis uses the $MANPATH environ-\nment variable, unless it is empty or unset,  in  which  case  it\nwill  determine an appropriate manpath based on your $PATH envi-\nronment variable.  This option overrides the contents  of  $MAN-\nPATH.\n\n-L locale, --locale=locale\nwhatis  will normally determine your current locale by a call to\nthe C function setlocale(3) which interrogates various  environ-\nment  variables,  possibly including $LCMESSAGES and $LANG.  To\ntemporarily override the determined value, use  this  option  to\nsupply  a  locale  string directly to whatis.  Note that it will\nnot take effect until the  search  for  pages  actually  begins.\nOutput  such as the help message will always be displayed in the\ninitially determined locale.\n\n-C file, --config-file=file\nUse this user configuration file  rather  than  the  default  of\n~/.manpath.\n\n-?, --help\nPrint a help message and exit.\n",
                    "flag": "-l",
                    "long": "--long"
                },
                {
                    "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\n16     Nothing was found that matched the criteria specified.\n",
            "subsections": []
        },
        "ENVIRONMENT": {
            "content": "SYSTEM If  $SYSTEM  is  set,  it will have the same effect as if it had\nbeen specified as the argument to the -m option.\n\nMANPATH\nIf $MANPATH is set, its value is interpreted as the colon-delim-\nited manual page hierarchy search path to use.\n\nSee the SEARCH PATH section of manpath(5) for the default behav-\niour and details of how this environment variable is handled.\n\nMANWIDTH\nIf $MANWIDTH is set, its value is used  as  the  terminal  width\n(see  the  --long option).  If it is not set, the terminal width\nwill be calculated using the value of $COLUMNS, and ioctl(2)  if\navailable, or falling back to 80 characters if all else fails.\n",
            "subsections": []
        },
        "FILES": {
            "content": "/usr/share/man/index.(bt|db|dir|pag)\nA traditional global index database cache.\n\n/var/cache/man/index.(bt|db|dir|pag)\nAn FHS compliant global index database cache.\n\n/usr/share/man/.../whatis\nA traditional whatis text database.\n",
            "subsections": []
        },
        "SEE ALSO": {
            "content": "apropos(1), man(1), mandb(8)\n",
            "subsections": []
        },
        "AUTHOR": {
            "content": "Wilf. (G.Wilford@ee.surrey.ac.uk).\nFabrizio Polacco (fpolacco@debian.org).\nColin Watson (cjwatson@debian.org).\n",
            "subsections": []
        },
        "BUGS": {
            "content": "https://gitlab.com/cjwatson/man-db/-/issues\nhttps://savannah.nongnu.org/bugs/?group=man-db\n\n2.10.2                            2022-03-17                         WHATIS(1)",
            "subsections": []
        }
    },
    "summary": "whatis - display one-line manual page descriptions",
    "flags": [
        {
            "flag": "-d",
            "long": "--debug",
            "arg": null,
            "description": "Print debugging information."
        },
        {
            "flag": "-v",
            "long": "--verbose",
            "arg": null,
            "description": "Print verbose warning messages."
        },
        {
            "flag": "-r",
            "long": "--regex",
            "arg": null,
            "description": "Interpret each name as a regular expression. If a name matches any part of a page name, a match will be made. This option causes whatis to be somewhat slower due to the nature of data- base searches."
        },
        {
            "flag": "-w",
            "long": "--wildcard",
            "arg": null,
            "description": "Interpret each name as a pattern containing shell style wild- cards. For a match to be made, an expanded name must match the entire page name. This option causes whatis to be somewhat slower due to the nature of database searches."
        },
        {
            "flag": "-l",
            "long": "--long",
            "arg": null,
            "description": "Do not trim output to the terminal width. Normally, output will be truncated to the terminal width to avoid ugly results from poorly-written NAME sections. -s list, --sections=list, --section=list Search only the given manual sections. list is a colon- or comma-separated list of sections. If an entry in list is a sim- ple section, for example \"3\", then the displayed list of de- scriptions will include pages in sections \"3\", \"3perl\", \"3x\", and so on; while if an entry in list has an extension, for exam- ple \"3perl\", then the list will only include pages in that exact part of the manual section. -m system[,...], --systems=system[,...] If this system has access to other operating systems' manual page names, they can be accessed using this option. To search NewOS's manual page names, 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 page names, include the system name man in the argument string. This option will override the $SYSTEM en- vironment variable. -M path, --manpath=path Specify an alternate set of colon-delimited manual page hierar- chies to search. By default, whatis uses the $MANPATH environ- ment variable, unless it is empty or unset, in which case it will determine an appropriate manpath based on your $PATH envi- ronment variable. This option overrides the contents of $MAN- PATH. -L locale, --locale=locale whatis will normally determine your current locale by a call to the C function setlocale(3) which interrogates various environ- ment variables, possibly including $LCMESSAGES and $LANG. To temporarily override the determined value, use this option to supply a locale string directly to whatis. 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. -C file, --config-file=file Use this user configuration file rather than the default of ~/.manpath. -?, --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": [],
    "see_also": [
        {
            "name": "apropos",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/apropos/1/json"
        },
        {
            "name": "man",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/man/1/json"
        },
        {
            "name": "mandb",
            "section": "8",
            "url": "https://www.chedong.com/phpMan.php/man/mandb/8/json"
        }
    ]
}