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
- -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 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 NAME sections.
- -s list, --sections 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.
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
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
- -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
- 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 (email@example.com).
Colin Watson (firstname.lastname@example.org).