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 spe-
cial 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. De-
pending 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 de-
fault 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 wild-
cards. 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 de-
scription 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 de-
fault 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 sim-
ple section, for example "3", then the displayed list of descrip-
tions 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
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 op-
erating system names. To include a search of the native operat-
ing system's whatis descriptions, include the system name man in
the argument string. This option will override the $SYSTEM envi-
ronment variable.
-M path, --manpath=path
Specify an alternate set of colon-delimited manual page hierar-
chies to search. By default, apropos 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 environment
variable. 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 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 apropos. Note that it will
not take effect until the search for pages actually begins. Out-
put such as the help message will always be displayed in the ini-
tially 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.
See the SEARCH PATH section of manpath(5) for the default behav-
iour 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 avail-
able, 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).
BUGS
https://gitlab.com/man-db/man-db/-/issues
https://savannah.nongnu.org/bugs/?group=man-db
2.13.1 2025-05-02 APROPOS(1)
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