WHATIS(1)                                                                               Manual pager utils                                                                               WHATIS(1)

NAME
       whatis - display one-line manual page descriptions

SYNOPSIS
       whatis [-dlv?V] [-r|-w] [-s list] [-m system[,...]] [-M path] [-L locale] [-C file] name ...

DESCRIPTION
       Each manual page has a short description available within it.  whatis searches the manual page names and displays the manual page descriptions of any name matched.

       name  may  contain  wildcards (-w) or be a regular expression (-r).  Using these options, it may be necessary to quote the name or escape (\) the special characters to stop the shell from
       interpreting them.

       index databases are used during the search, and are 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.  To produce an old style text whatis database from the relative index database, issue the command:

       whatis -M manpath -w '*' | sort > manpath/whatis

       where manpath is a manual page hierarchy such as /usr/man.

OPTIONS
       -d, --debug
              Print debugging information.

       -v, --verbose
              Print verbose warning messages.

       -r, --regex
              Interpret each name as a regular expression.  If a name matches any part of a page name, a match will be made.  This option causes whatis to be somewhat slower due to the nature of
              database searches.

       -w, --wildcard
              Interpret each name as a pattern containing shell style wildcards.  For a match to be made, an expanded name must match the entire page name.  This option causes whatis to be some‐
              what slower due to the nature of database searches.

       -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 names, they can be accessed using this option.  To search NewOS's manual page names, 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 manual page names, 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, whatis 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
              whatis  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 whatis.  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.

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
       apropos(1), man(1), mandb(8)

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

2.7.6.1                                                                                     2016-12-12                                                                                   WHATIS(1)