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       apropos - search the manual page names and descriptions


       apropos  [-dalhvV]  [-e|-w|-r] [-s section] [-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 section, --section section
              Search only the given manual section.  If section  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  section  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

       -h, --help
              Print a help 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 an ioctl(2) if available, the value of
              $COLUMNS, 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.


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


       Wilf. (
       Fabrizio Polacco (
       Colin Watson (