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APROPOS(1) FreeBSD General Commands Manual APROPOS(1)
NAME apropos, whatis - search manual page databases
SYNOPSIS apropos [-afk] [-C file] [-M path] [-m path] [-O outkey] [-S arch] [-s section] expression ...
DESCRIPTION The apropos and whatis utilities query manual page databases generated by makewhatis(8), evaluating expression for each file in each database. By default, they display the names, section numbers, and description lines of all matching manuals.
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 (the Nm and 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.
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.
( expr ) 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...]](=|~)]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 ~ 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
name[, name...](sec) - description
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
name(sec/arch) - description
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
Macro Keys Queries evaluate over a subset of mdoc(7) macros indexed by makewhatis(8). In addition to the macro keys listed below, the special key any may be used to match any available macro key.
Names and description: Nm manual name Nd one-line manual description arch machine architecture (case-insensitive) sec manual section number
Sections and cross references: Cm command modifier Ar command argument Ic internal or interactive command Ev environmental variable Pa file system path
Semantic markup for function libraries: Lb function library name In include file Ft function return type Fn function name Fa function argument type and name Vt variable type Va variable name Dv defined variable or preprocessor constant Er error constant Ev environmental variable
Various semantic markup: An author name Lk hyperlink Mt "mailto" hyperlink Cd kernel configuration declaration Ms mathematical symbol Tn tradename
Physical markup: Em italic font or underline Sy boldface font Li typewriter font
Text production: St reference to a standards document At AT&T UNIX version reference Bx BSD version reference Bsx BSD/OS version reference Nx NetBSD version reference Fx FreeBSD version reference Ox OpenBSD version reference Dx DragonFly 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:
Fa function arguments appearing on Fn lines Fn function names marked up with Fo macros In include file names marked up with Fd macros Vt types appearing as function return types and types appearing in function arguments in the SYNOPSIS
ENVIRONMENT MANPAGER Any non-empty value of the environment variable MANPAGER is used instead of the standard pagination program, less(1); see man(1) for details. Only used if -a or -l is specified.
MANPATH A colon-separated list of directories to search for manual pages; see man(1) for details. Overridden by -M, ignored if -l is specified.
/etc/man.conf default man(1) configuration file
EXIT STATUS The apropos utility exits 0 on success, and >0 if an error occurs.
EXAMPLES Search for ".cf" as a substring of manual names and descriptions:
$ apropos =.cf
Include matches for ".cnf" and ".conf" as well:
$ apropos =.cf =.cnf =.conf
Search in names and descriptions using a case-sensitive regular expression:
$ apropos '~set.?[ug]id'
Search for all manual pages in a given section:
$ apropos -s 9 .
Search for manuals in the library section mentioning both the "optind" and the "optarg" variables:
$ apropos -s 3 Va=optind -a Va=optarg
Do exactly the same as calling whatis with the argument "ssh":
$ apropos -- -i 'Nm~[[:<:]]ssh[[:>:]]'
The following two invocations are equivalent:
$ apropos -S arch -s section expression
$ apropos \( expression \) -a arch~^(arch|any)$ -a sec~^section$
SEE ALSO man(1), re_format(7), makewhatis(8)
STANDARDS The apropos utility is compliant with the IEEE Std 1003.1-2008 ("POSIX.1") specification of man(1) -k.
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.
HISTORY Part of the functionality of whatis was already provided by the former manwhere utility in 1BSD. The apropos and whatis utilities first appeared in 2BSD. They were rewritten from scratch for OpenBSD 5.6.
The -M option and the MANPATH variable first appeared in 4.3BSD; -m in 4.3BSD-Reno; -C in 4.4BSD-Lite1; and -S and -s in OpenBSD 4.5 for apropos and in OpenBSD 5.6 for whatis. The options -acfhIKklOTWw appeared in OpenBSD 5.7.