Provided by: mandoc_1.14.6-3_amd64 
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.
-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.
( 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:
Sh section header (excluding standard sections)
Ss subsection header
Xr cross reference to another manual page
Rs bibliographic reference
Semantic markup for command line utilities:
Fl command line options (flags)
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.
PAGER Specifies the pagination program to use when MANPAGER is not defined. If neither
PAGER nor MANPAGER is defined, less(1) is used. Only used if -a or -l is
specified.
FILES
mandoc.db name of the makewhatis(8) keyword database
/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.
AUTHORS
Bill Joy wrote manwhere in 1977 and the original BSD apropos and whatis in February 1979.
The current version was written by Kristaps Dzonsons <kristaps@bsd.lv> and Ingo Schwarze
<schwarze@openbsd.org>.