whatis

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 lo-
       cale] [-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 descrip-
       tions 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 data-
       base 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  data-
              base searches.

       -w, --wildcard
              Interpret  each  name  as a pattern containing shell style wild-
              cards.  For a match to be made, an expanded name must match  the
              entire  page  name.   This  option  causes whatis to be somewhat
              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 sim-
              ple section, for example "3", then the  displayed  list  of  de-
              scriptions  will  include  pages in sections "3", "3perl", "3x",
              and so on; while if an entry in list has an extension, for exam-
              ple "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 op-
              erating system names.  To include a search of the native operat-
              ing system's manual page names, include the system name  man  in
              the  argument string.  This option will override the $SYSTEM en-
              vironment variable.

       -M path, --manpath=path
              Specify an alternate set of colon-delimited manual page  hierar-
              chies  to search.  By default, whatis uses the $MANPATH environ-
              ment variable, unless it is empty or unset,  in  which  case  it
              will  determine an appropriate manpath based on your $PATH envi-
              ronment variable.  This option overrides the contents  of  $MAN-
              PATH.

       -L locale, --locale=locale
              whatis  will normally determine your current locale by a call to
              the C function setlocale(3) which interrogates various  environ-
              ment  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-delim-
              ited 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, and 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).

2.9.1                             2020-02-25                         WHATIS(1)