whatis(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXIT STATUS | ENVIRONMENT | FILES | SEE ALSO | AUTHOR | BUGS | COLOPHON

WHATIS(1)                   Manual pager utils                  WHATIS(1)

NAME         top

       whatis - display one-line manual page descriptions

SYNOPSIS         top

       whatis [-dlv?V] [-r|-w] [-s list] [-m system[,...]] [-M path] [-L
       locale] [-C file] name ...

DESCRIPTION         top

       Each manual page has a short description available within it.
       whatis searches the manual page names and displays the manual page
       descriptions of any name matched.

       name may contain wildcards (-w) or be a regular expression (-r).
       Using these options, it may be necessary to quote the name or
       escape (\) the special characters to stop the shell from
       interpreting them.

       index databases are used during the search, and are updated by the
       mandb program.  Depending on your installation, this may be run by
       a periodic cron job, or may need to be run manually after new
       manual pages have been installed.  To produce an old style text
       whatis database from the relative index database, issue the
       command:

       whatis -M manpath -w '*' | sort > manpath/whatis

       where manpath is a manual page hierarchy such as /usr/man.

OPTIONS         top

       -d, --debug
              Print debugging information.

       -v, --verbose
              Print verbose warning messages.

       -r, --regex
              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.

       -w, --wildcard
              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.

       -l, --long
              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
              simple section, for example "3", then the displayed 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.

       -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 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 environment variable.

       -M path, --manpath=path
              Specify an alternate set of colon-delimited manual page
              hierarchies to search.  By default, 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.

       -L locale, --locale=locale
              whatis 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 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.

       --usage
              Print a short usage message and exit.

       -V, --version
              Display version information.

EXIT STATUS         top

       0      Successful program execution.

       1      Usage, syntax or configuration file error.

       2      Operational error.

       16     Nothing was found that matched the criteria specified.

ENVIRONMENT         top

       SYSTEM If $SYSTEM is set, it will have the same effect as if it
              had been specified as the argument to the -m option.

       MANPATH
              If $MANPATH is set, its value is interpreted as the colon-
              delimited manual page hierarchy search path to use.

              See the SEARCH PATH section of manpath(5) for the default
              behaviour and details of how this environment variable is
              handled.

       MANWIDTH
              If $MANWIDTH is set, its value is used as the terminal
              width (see the --long option).  If it is not set, the
              terminal width will be calculated using the value of
              $COLUMNS, and ioctl(2) if available, or falling back to 80
              characters if all else fails.

FILES         top

       /usr/share/man/index.(bt|db|dir|pag)
              A traditional global index database cache.

       /var/cache/man/index.(bt|db|dir|pag)
              An FHS compliant global index database cache.

       /usr/share/man/.../whatis
              A traditional whatis text database.

SEE ALSO         top

       apropos(1), man(1), mandb(8)

AUTHOR         top

       Wilf. ([email protected]).
       Fabrizio Polacco ([email protected]).
       Colin Watson ([email protected]).

BUGS         top

       https://gitlab.com/man-db/man-db/-/issues
       https://savannah.nongnu.org/bugs/?group=man-db

COLOPHON         top

       This page is part of the man-db (manual pager suite) project.
       Information about the project can be found at 
       ⟨http://www.nongnu.org/man-db/⟩.  If you have a bug report for this
       manual page, send it to [email protected].  This page was
       obtained from the project's upstream Git repository
       ⟨https://gitlab.com/cjwatson/man-db⟩ on 2025-02-02.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2025-01-24.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there is
       a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       [email protected]

2.13.0                          2024-08-29                      WHATIS(1)

Pages that refer to this page: apropos(1)lexgrog(1)man(1)manpath(1)uri(7)