apropos - search the manual page names and descriptions
] [-m system
[,...]] [-M path
] [-C file
Each manual page has a short description available within it. apropos
searches the descriptions for instances of 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
(\) 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
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.
- -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 description or page name.
Otherwise the keyword is also allowed to match on word boundaries in the
- -e, --exact
- Each keyword will be exactly matched against the page names and the
- -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
- -s list, --sections list, --section
- 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.
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
specified can be a combination of comma-delimited operating
system names. To include a search of the native operating system's
descriptions, include the system name man
in the argument
string. This option will override the $SYSTEM
- -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 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 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
- -C file, --config-file=file
- Use this user configuration file rather than the default of
- -?, --help
- Print a help message and exit.
- Print a short usage message and exit.
- -V, --version
- Display version information.
- Successful program execution.
- Usage, syntax or configuration file error.
- Operational error.
- Nothing was found that matched the criteria specified.
- If $SYSTEM is set, it will have the same effect as if it had been
specified as the argument to the -m option.
- If $MANPATH is set, its value is interpreted as the colon-delimited
manual page hierarchy search path to use.
- 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.
- 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.
- A traditional global index database cache.
- An FHS compliant global index database cache.
- A traditional whatis text database.
Fabrizio Polacco (firstname.lastname@example.org).
Colin Watson (email@example.com).