Manual Pages  — APROPOS

By default, apropos searches for makewhatis(8) databases in the default paths stipulated by man(1) and uses case-insensitive extended regular expression matching over manual names and descriptions (theamp;Nm andamp;Nd macro keys). Multiple terms imply pairwise -o.

whatis is a synonym for apropos -f.

The options are as follows:

-a
	Instead of showing only the title lines, show the complete manual pages, just like man(1) -a would. If the standard output is a terminal device and -c is not specified, use less(1) to paginate them. In -a mode, the options -IKOTW described in the mandoc(1) manual are also available.
-C file
	Specify an alternative configuration file in man.conf(5) format.
-f
	Search for all words in expression in manual page names only. The search is case-insensitive and matches whole words only. In this mode, macro keys, comparison operators, and logical operators are not available.
-k
	Support the full expression syntax. It is the default for apropos.
-M path
	Use the colon-separated path instead of the default list of paths searched for makewhatis(8) databases. Invalid paths, or paths without manual databases, are ignored.
-m path
	Prepend the colon-separated paths to the list of paths searched for makewhatis(8) databases. Invalid paths, or paths without manual databases, are ignored.
-O outkey
	Show the values associated with the key outkey instead of the manual descriptions.
-S arch
	Restrict the search to pages for the specified machine(1) architecture. arch is case-insensitive. By default, pages for all architectures are shown.
-s section
	Restrict the search to the specified section of the manual. By default, pages from all sections are shown. See man(1) for a listing of sections.

The options -chlw are also supported and are documented in man(1). The options -fkl are mutually exclusive and override each other.

An expression consists of search terms joined by logical operators -a (and) and -o (or). The -a operator has precedence over -o and both are evaluated left-to-right.

amp;( expr amp;)
	True if the subexpression expr is true.
expr1 -a expr2
	True if both expr1 and expr2 are true (logical 'and').
expr1 [-o ]expr2
	True if expr1 and/or expr2 evaluate to true (logical 'or').
term	True if term is satisfied. This has syntax [[key [, key ...]](=|ti)]val,where key is an mdoc(7) macro to query and val is its value. See Macro Keys for a list of available keys. Operator = evaluates a substring, while ti evaluates a case-sensitive extended regular expression.
-i term
	If term is a regular expression, it is evaluated case-insensitively. Has no effect on substring terms.

Results are sorted first according to the section number in ascending numerical order, then by the page name in ascending ascii(7) alphabetical order, case-insensitive.

Each output line is formatted as

Where "name" is the manual's name, "sec" is the manual section, and "description" is the manual's short description. If an architecture is specified for the manual, it is displayed as

Resulting manuals may be accessed as

    $ man -s sec name

If an architecture is specified in the output, use

    $ man -s sec -S arch name

Names and description:

amp;Nm	manual name
amp;Nd	one-line manual description
arch	machine architecture (case-insensitive)
sec	manual section number

Sections and cross references:

amp;Sh	section header (excluding standard sections)
amp;Ss	subsection header
amp;Xr	cross reference to another manual page
amp;Rs	bibliographic reference

Semantic markup for command line utilities:

amp;Fl	command line options (flags)
amp;Cm	command modifier
amp;Ar	command argument
amp;Ic	internal or interactive command
amp;Ev	environmental variable
amp;Pa	file system path

Semantic markup for function libraries:

amp;Lb	function library name
amp;In	include file
amp;Ft	function return type
amp;Fn	function name
amp;Fa	function argument type and name
amp;Vt	variable type
amp;Va	variable name
amp;Dv	defined variable or preprocessor constant
amp;Er	error constant
amp;Ev	environmental variable

Various semantic markup:

amp;An	author name
amp;Lk	hyperlink
amp;Mt	"mailto "hyperlink
amp;Cd	kernel configuration declaration
amp;Ms	mathematical symbol
amp;Tn	tradename

Physical markup:

amp;Em	italic font or underline
amp;Sy	boldface font
amp;Li	typewriter font

Text production:

amp;St	reference to a standards document
amp;At	At version reference
amp;Bx	Bx version reference
amp;Bsx	Bsx version reference
amp;Nx	Nx version reference
amp;Fx	Fx version reference
amp;Ox	Ox version reference
amp;Dx	Dx version reference

In general, macro keys are supposed to yield complete results without expecting the user to consider actual macro usage. For example, results include:

amp;Fa	function arguments appearing on amp;Fn lines
amp;Fn	function names marked up with amp;Fo macros
amp;In	include file names marked up with amp;Fd macros
amp;Vt	types appearing as function return types and
amp;	types appearing in function arguments in the SYNOPSIS

All options, the whatis command, support for logical operators, macro keys, substring matching, sorting of results, the environment variables MANPAGER and MANPATH, the database format, and the configuration file are extensions to that specification.