apropos(1) — Linux manual page


APROPOS(1)                 Manual pager utils                 APROPOS(1)

NAME         top

       apropos - search the manual page names and descriptions

SYNOPSIS         top

       apropos [-dalv?V] [-e|-w|-r] [-s list] [-m system[,...]] [-M
       path] [-L locale] [-C file] keyword ...

DESCRIPTION         top

       Each manual page has a short description available within it.
       apropos searches the descriptions for instances of keyword.

       keyword is usually a regular expression, as if (-r) was used, or
       may contain wildcards (-w), or match the exact keyword (-e).
       Using these options, it may be necessary to quote the keyword or
       escape (\) the special characters to stop the shell from
       interpreting them.

       The standard matching rules allow matches to be made against the
       page name and word boundaries in the description.

       The database searched by apropos is 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.

OPTIONS         top

       -d, --debug
              Print debugging information.

       -v, --verbose
              Print verbose warning messages.

       -r, --regex
              Interpret each keyword as a regular expression.  This is
              the default behaviour.  Each keyword will be matched
              against the page names and the descriptions independently.
              It can match any part of either.  The match is not limited
              to word boundaries.

       -w, --wildcard
              Interpret each keyword as a pattern containing shell style
              wildcards.  Each keyword will be matched against the page
              names and the descriptions independently.  If --exact is
              also used, a match will only be found if an expanded
              keyword matches an entire description or page name.
              Otherwise the keyword is also allowed to match on word
              boundaries in the description.

       -e, --exact
              Each keyword will be exactly matched against the page
              names and the descriptions.

       -a, --and
              Only display items that match all the supplied keywords.
              The default is to display items that match any keyword.

       -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 descriptions, they can be searched using this
              option.  To search NewOS's manual page descriptions, 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 whatis descriptions, 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, apropos 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
              apropos 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 apropos.  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.

              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.

              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

              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.

              If $POSIXLY_CORRECT is set, even to a null value, the
              default apropos search will be as an extended regex (-r).
              Nowadays, this is the default behaviour anyway.

FILES         top

              A traditional global index database cache.

              An FHS compliant global index database cache.

              A traditional whatis text database.

SEE ALSO         top

       man(1), whatis(1), mandb(8)

AUTHOR         top

       Wilf. (G.Wilford@ee.surrey.ac.uk).
       Fabrizio Polacco (fpolacco@debian.org).
       Colin Watson (cjwatson@debian.org).

BUGS         top


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 man-db-devel@nongnu.org.  This page
       was obtained from the project's upstream Git repository
       ⟨https://gitlab.com/cjwatson/man-db⟩ on 2023-12-22.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2023-12-18.)  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

2.12.0                         2023-09-23                     APROPOS(1)

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