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

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

       -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

       -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 system's manual
              page descriptions, they can be searched using this option.  To
              search NewOS's manual page descriptions, use the option -m

              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

       -?, --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.

              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

              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
       ⟨http://git.savannah.gnu.org/r/man-db.git⟩ on 2020-07-14.  (At that
       time, the date of the most recent commit that was found in the repos‐
       itory was 2020-07-04.)  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 man-pages@man7.org

2.8.4                            2018-07-27                       APROPOS(1)

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