NAME
apropos - search the manual page names and descriptions
SYNOPSIS
apropos [-dalhvV] [-e|-w|-r] [-s section] [-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
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 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.
OPTIONS
-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 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
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 section, --section section
Search only the given manual section. If section 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 section 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 system's 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
operating system names. To include a search of the native
operating system's whatis descriptions, 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, 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 locale.
-C file, --config-file=file
Use this user configuration file rather than the default of
~/.manpath.
-h, --help
Print a help 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-
delimited 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 an ioctl(2) if available, the value of
$COLUMNS, 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
whatis(1), man(1), mandb(8).
AUTHOR
Wilf. (G.Wilford@ee.surrey.ac.uk).
Fabrizio Polacco (fpolacco@debian.org).
Colin Watson (cjwatson@debian.org).