apropos - search the manual page names and descriptions


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


   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


   -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  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

   -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.


   0      Successful program execution.

   1      Usage, syntax or configuration file error.

   2      Operational error.

   16     Nothing was found that matched the criteria specified.


   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, an  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.


          A traditional global index database cache.

          An FHS compliant global index database cache.

          A traditional whatis text database.


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


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


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