APROPOS(1)							Manual pager utils							APROPOS(1)

NAME

       apropos - search the manual page names and descriptions

SYNOPSIS

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

DESCRIPTION

       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

       -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 descrip-
	      tion 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 sec-
	      tion, 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 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  vari-
	      able.  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.

       --usage
	      Print a short usage message and exit.

       -V, --version
	      Display version information.

EXIT STATUS

       0      Successful program execution.

       1      Usage, syntax or configuration file error.

       2      Operational error.

       16     Nothing was found that matched the criteria specified.

ENVIRONMENT

       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.

       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, an ioctl(2) if available, or falling back to 80 characters if all else fails.

       POSIXLY_CORRECT
	      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

       /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

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

AUTHOR

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

2.8.3								    2018-04-05								APROPOS(1)