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HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXIT STATUS | ENVIRONMENT | FILES | SEE ALSO | AUTHOR | BUGS | COLOPHON |
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WHATIS(1) Manual pager utils WHATIS(1)
whatis - display one-line manual page descriptions
whatis [-dlv?V] [-r|-w] [-s list] [-m system[,...]] [-M path] [-L
locale] [-C file] name ...
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.
-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 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
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 systems'
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.
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.
MANPATH
If $MANPATH is set, its value is interpreted as the colon-
delimited manual page hierarchy search path to use.
See the SEARCH PATH section of manpath(5) for the default
behaviour and details of how this environment variable is
handled.
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.
/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.
apropos(1), man(1), mandb(8)
Wilf. ([email protected]).
Fabrizio Polacco ([email protected]).
Colin Watson ([email protected]).
https://gitlab.com/man-db/man-db/-/issues
https://savannah.nongnu.org/bugs/?group=man-db
This page is part of the man-db (manual pager suite) project.
Information about the project can be found at
⟨http://www.nongnu.org/man-db/⟩. If you have a bug report for this
manual page, send it to [email protected]. This page was
obtained from the project's upstream Git repository
⟨https://gitlab.com/cjwatson/man-db⟩ on 2025-08-11. (At that
time, the date of the most recent commit that was found in the
repository was 2025-05-19.) If you discover any rendering
problems in this HTML version of the page, or you believe there is
a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
[email protected]
2.13.1 2025-05-02 WHATIS(1)
Pages that refer to this page: apropos(1), lexgrog(1), man(1), manpath(1), uri(7)
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HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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