{
    "mode": "man",
    "parameter": "WHATIS",
    "section": "1",
    "url": "https://www.chedong.com/phpMan.php/man/WHATIS/1/json",
    "generated": "2026-10-08T19:44:01Z",
    "synopsis": "whatis [-dlv?V] [-r|-w] [-s list] [-m system[,...]] [-M path] [-L locale] [-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 locale] [-C file] name ...\n",
            "subsections": []
        },
        "DESCRIPTION": {
            "content": "Each  manual  page  has  a short description available within it.  whatis searches the manual\npage names and displays the manual page descriptions of any name matched.\n\nname may contain wildcards (-w) or be a regular expression (-r).  Using these options, it may\nbe necessary to quote the name or escape (\\) the special characters to stop  the  shell  from\ninterpreting them.\n\nindex  databases are used during the search, and are updated by the mandb program.  Depending\non your installation, this may be run by a periodic cron job, or may need to be run  manually\nafter  new  manual  pages  have been installed.  To produce an old style text whatis database\nfrom 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 any  part  of  a  page\nname,  a  match  will be made.  This option causes whatis to be somewhat slower due to\nthe nature of database searches.\n",
                    "flag": "-r",
                    "long": "--regex"
                },
                {
                    "name": "-w --wildcard",
                    "content": "Interpret each name as a pattern containing shell style wildcards.  For a match to  be\nmade,  an expanded name must match the entire page name.  This option causes whatis to\nbe somewhat slower 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 be truncated  to  the\nterminal width to avoid ugly results from poorly-written NAME sections.\n",
                    "flag": "-l",
                    "long": "--long"
                },
                {
                    "name": "-s _ --sections=_ --section=_",
                    "content": "Search  only  the  given manual sections.  list is a colon- or comma-separated list of\nsections.  If an entry in list is a simple section, for example  \"3\",  then  the  dis‐\nplayed  list of descriptions will include pages in sections \"3\", \"3perl\", \"3x\", and so\non; while if an entry in list has an extension, for example  \"3perl\",  then  the  list\nwill only include pages in that exact part of the manual section.\n",
                    "flag": "-s",
                    "long": "--section",
                    "arg": "_"
                },
                {
                    "name": "-m _ --systems=_",
                    "content": "If  this  system has access to other operating systems' manual page names, they can be\naccessed using this option.  To search NewOS's manual page names, use  the  option  -m\nNewOS.\n\nThe  system  specified can be a combination of comma delimited operating system names.\nTo include a search of the native operating system's manual page  names,  include  the\nsystem  name  man in the argument string.  This option will override the $SYSTEM envi‐\nronment variable.\n",
                    "flag": "-m",
                    "long": "--systems",
                    "arg": "_"
                },
                {
                    "name": "-M _ --manpath=_",
                    "content": "Specify an alternate set of colon-delimited manual page hierarchies to search.  By de‐\nfault, whatis uses the $MANPATH environment variable, unless it is empty or unset,  in\nwhich  case  it  will determine an appropriate manpath based on your $PATH environment\nvariable.  This option overrides the contents of $MANPATH.\n",
                    "flag": "-M",
                    "long": "--manpath",
                    "arg": "_"
                },
                {
                    "name": "-L _ --locale=_",
                    "content": "whatis will normally determine your current locale by a call to the C function  setlo‐\ncale(3)  which interrogates various environment variables, possibly including $LCMES‐\nSAGES and $LANG.  To temporarily override the determined value,  use  this  option  to\nsupply  a  locale  string directly to whatis.  Note that it will not take effect until\nthe search for pages actually begins.  Output such as the help message will always  be\ndisplayed in the initially determined locale.\n",
                    "flag": "-L",
                    "long": "--locale",
                    "arg": "_"
                },
                {
                    "name": "-C _ --config-file=_",
                    "content": "Use this user configuration file rather than the default of ~/.manpath.\n\n-?, --help\nPrint a help message and exit.\n",
                    "flag": "-C",
                    "long": "--config-file",
                    "arg": "_"
                },
                {
                    "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 been specified as the ar‐\ngument to the -m option.\n\nMANPATH\nIf  $MANPATH is set, its value is interpreted as the colon-delimited manual page hier‐\narchy search path to use.\n\nSee the SEARCH PATH section of manpath(5) for the default behaviour and details of how\nthis environment variable is handled.\n\nMANWIDTH\nIf $MANWIDTH is set, its value is used as the terminal width (see the --long  option).\nIf  it  is not set, the terminal width will be calculated using the value of $COLUMNS,\nand ioctl(2) if available, 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/man-db/man-db/-/issues\nhttps://savannah.nongnu.org/bugs/?group=man-db\n\n2.12.0                                       2023-09-23                                    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 database searches."
        },
        {
            "flag": "-w",
            "long": "--wildcard",
            "arg": null,
            "description": "Interpret each name as a pattern containing shell style wildcards. 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."
        },
        {
            "flag": "-s",
            "long": "--section",
            "arg": "_",
            "description": "Search only the given manual sections. list is a colon- or comma-separated list of sections. If an entry in list is a simple section, for example \"3\", then the dis‐ played list of descriptions will include pages in sections \"3\", \"3perl\", \"3x\", and so on; while if an entry in list has an extension, for example \"3perl\", then the list will only include pages in that exact part of the manual section."
        },
        {
            "flag": "-m",
            "long": "--systems",
            "arg": "_",
            "description": "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 operating system names. To include a search of the native operating system's manual page names, include the system name man in the argument string. This option will override the $SYSTEM envi‐ ronment variable."
        },
        {
            "flag": "-M",
            "long": "--manpath",
            "arg": "_",
            "description": "Specify an alternate set of colon-delimited manual page hierarchies to search. By de‐ fault, whatis uses the $MANPATH environment variable, unless it is empty or unset, in which case it will determine an appropriate manpath based on your $PATH environment variable. This option overrides the contents of $MANPATH."
        },
        {
            "flag": "-L",
            "long": "--locale",
            "arg": "_",
            "description": "whatis will normally determine your current locale by a call to the C function setlo‐ cale(3) which interrogates various environment variables, possibly including $LCMES‐ SAGES 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."
        },
        {
            "flag": "-C",
            "long": "--config-file",
            "arg": "_",
            "description": "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"
        }
    ],
    "tldr": {
        "source": "official",
        "description": "Display one-line descriptions from manual pages.",
        "examples": [
            {
                "description": "Display a description from a man page",
                "command": "whatis {{command}}"
            },
            {
                "description": "Don't cut the description off at the end of the line",
                "command": "whatis {{-l|--long}} {{command}}"
            },
            {
                "description": "Display descriptions for all commands matching a `glob`",
                "command": "whatis {{-w|--wildcard}} {{net*}}"
            },
            {
                "description": "Search man page descriptions with a `regex`",
                "command": "whatis {{-r|--regex}} '{{wish[0-9]\\.[0-9}}'"
            },
            {
                "description": "Display descriptions in a specific language",
                "command": "whatis {{-L|--locale}} {{en}} {{command}}"
            }
        ]
    }
}