Only sort the result array if it contains more than one element,

[mandoc.git] / apropos.1

diff --git a/apropos.1 b/apropos.1
index 4706d36a626d2951945b461d7dd01795fb0051b3..9129ae31f126b8598aece0d3db98d734bd1f9d00 100644 (file)
--- a/apropos.1
+++ b/apropos.1
@@ -1,6 +1,7 @@
-.\"    $Id: apropos.1,v 1.18 2012/06/08 10:44:52 kristaps Exp $
+.\" $Id: apropos.1,v 1.51 2020/10/01 22:50:00 schwarze Exp $

 .\"
 .\" Copyright (c) 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>
 .\"
 .\" Copyright (c) 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>

+.\" Copyright (c) 2011,2012,2014,2017,2018 Ingo Schwarze <schwarze@openbsd.org>

 .\"
 .\" Permission to use, copy, modify, and distribute this software for any
 .\" purpose with or without fee is hereby granted, provided that the above
 .\"
 .\" Permission to use, copy, modify, and distribute this software for any
 .\" purpose with or without fee is hereby granted, provided that the above


@@ -14,109 +15,230 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"

-.Dd $Mdocdate: June 8 2012 $
+.Dd $Mdocdate: October 1 2020 $

 .Dt APROPOS 1
 .Os
 .Sh NAME
 .Dt APROPOS 1
 .Os
 .Sh NAME

-.Nm apropos
+.Nm apropos ,
+.Nm whatis

 .Nd search manual page databases
 .Sh SYNOPSIS
 .Nm
 .Nd search manual page databases
 .Sh SYNOPSIS
 .Nm

+.Op Fl afk

 .Op Fl C Ar file
 .Op Fl C Ar file

-.Op Fl M Ar manpath
-.Op Fl m Ar manpath
+.Op Fl M Ar path
+.Op Fl m Ar path
+.Op Fl O Ar outkey

 .Op Fl S Ar arch
 .Op Fl s Ar section
 .Ar expression ...
 .Sh DESCRIPTION
 The
 .Op Fl S Ar arch
 .Op Fl s Ar section
 .Ar expression ...
 .Sh DESCRIPTION
 The

-.Nm
-utility queries manual page databases generated by
-.Xr mandocdb 8 ,
-evaluating on
+.Nm apropos
+and
+.Nm whatis
+utilities query manual page databases generated by
+.Xr makewhatis 8 ,
+evaluating

 .Ar expression
 for each file in each database.
 .Ar expression
 for each file in each database.

+By default, they display the names, section numbers, and description lines
+of all matching manuals.

 .Pp
 By default,
 .Nm
 searches for
 .Pp
 By default,
 .Nm
 searches for

-.Xr mandocdb 8
+.Xr makewhatis 8

 databases in the default paths stipulated by
 .Xr man 1
 databases in the default paths stipulated by
 .Xr man 1

-and
-parses terms as case-sensitive words
-over manual names and descriptions.
-Multiple terms are OR'd.
+and uses case-insensitive extended regular expression matching
+over manual names and descriptions
+.Pq the Li \&Nm No and Li \&Nd No macro keys .
+Multiple terms imply pairwise
+.Fl o .

 .Pp
 .Pp

-Its arguments are as follows:
+.Nm whatis
+is a synonym for
+.Nm
+.Fl f .
+.Pp
+The options are as follows:

 .Bl -tag -width Ds
 .Bl -tag -width Ds

+.It Fl a
+Instead of showing only the title lines, show the complete manual pages,
+just like
+.Xr man 1
+.Fl a
+would.
+If the standard output is a terminal device and
+.Fl c
+is not specified, use
+.Xr less 1
+to paginate them.
+In
+.Fl a
+mode, the options
+.Fl IKOTW
+described in the
+.Xr mandoc 1
+manual are also available.

 .It Fl C Ar file
 Specify an alternative configuration
 .Ar file
 in
 .Xr man.conf 5
 format.
 .It Fl C Ar file
 Specify an alternative configuration
 .Ar file
 in
 .Xr man.conf 5
 format.

-.It Fl M Ar manpath
+.It Fl f
+Search for all words in
+.Ar 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.
+.It Fl k
+Support the full
+.Ar expression
+syntax.
+It is the default for
+.Nm .
+.It Fl M Ar path

 Use the colon-separated path instead of the default list of paths
 searched for
 Use the colon-separated path instead of the default list of paths
 searched for

-.Xr mandocdb 8
+.Xr makewhatis 8

 databases.
 Invalid paths, or paths without manual databases, are ignored.
 databases.
 Invalid paths, or paths without manual databases, are ignored.

-.It Fl m Ar manpath
+.It Fl m Ar path

 Prepend the colon-separated paths to the list of paths searched
 for
 Prepend the colon-separated paths to the list of paths searched
 for

-.Xr mandocdb 8
+.Xr makewhatis 8

 databases.
 Invalid paths, or paths without manual databases, are ignored.
 databases.
 Invalid paths, or paths without manual databases, are ignored.

+.It Fl O Ar outkey
+Show the values associated with the key
+.Ar outkey
+instead of the manual descriptions.

 .It Fl S Ar arch
 .It Fl S Ar arch

-Search only for a particular architecture.
-.It Fl s Ar cat
-Search only for a manual section.
+Restrict the search to pages for the specified
+.Xr machine 1
+architecture.
+.Ar arch
+is case-insensitive.
+By default, pages for all architectures are shown.
+.It Fl s Ar section
+Restrict the search to the specified section of the manual.
+By default, pages from all sections are shown.

 See
 .Xr man 1
 See
 .Xr man 1

-for a listing of manual sections.
+for a listing of sections.

 .El
 .Pp
 .El
 .Pp

+The options
+.Fl chlw
+are also supported and are documented in
+.Xr man 1 .
+The options
+.Fl fkl
+are mutually exclusive and override each other.
+.Pp

 An
 .Ar expression
 An
 .Ar expression

-consists of type and keyword pairs.
-This pair syntax
-.Li [key[,key]*(=~)]?val ,
-where operand
-.Cm key
+consists of search terms joined by logical operators
+.Fl a
+.Pq and
+and
+.Fl o
+.Pq or .
+The
+.Fl a
+operator has precedence over
+.Fl o
+and both are evaluated left-to-right.
+.Bl -tag -width Ds
+.It \&( Ar expr No \&)
+True if the subexpression
+.Ar expr
+is true.
+.It Ar expr1 Fl a Ar expr2
+True if both
+.Ar expr1
+and
+.Ar expr2
+are true (logical
+.Sq and ) .
+.It Ar expr1 Oo Fl o Oc Ar expr2
+True if
+.Ar expr1
+and/or
+.Ar expr2
+evaluate to true (logical
+.Sq or ) .
+.It Ar term
+True if
+.Ar term
+is satisfied.
+This has syntax
+.Sm off
+.Oo
+.Op Ar key Op , Ar key ...
+.Pq Cm = | \(ti
+.Oc
+.Ar val ,
+.Sm on
+where
+.Ar key

 is an
 .Xr mdoc 7
 macro to query and
 is an
 .Xr mdoc 7
 macro to query and

-.Cm val
+.Ar val

 is its value.
 See
 .Sx Macro Keys
 for a list of available keys.
 Operator
 is its value.
 See
 .Sx Macro Keys
 for a list of available keys.
 Operator

-.Li \&=
-evaluates a full string, while
-.Li \&~
-evaluates a
-.Xr glob 7
-pattern.
-.Pp
-Results are sorted by manual title, with output formatted as
-.Qq title(sec) \- description
-where
-.Qq title
-is the manual's title (note multiple manual names may exist for one
-title),
-.Qq sec
+.Cm =
+evaluates a substring, while
+.Cm \(ti
+evaluates a case-sensitive extended regular expression.
+.It Fl i Ar term
+If
+.Ar term
+is a regular expression, it
+is evaluated case-insensitively.
+Has no effect on substring terms.
+.El
+.Pp
+Results are sorted first according to the section number in ascending
+numerical order, then by the page name in ascending
+.Xr ascii 7
+alphabetical order, case-insensitive.
+.Pp
+Each output line is formatted as
+.Pp
+.D1 name[, name...](sec) \- description
+.Pp
+Where
+.Dq name
+is the manual's name,
+.Dq sec

 is the manual section, and
 is the manual section, and

-.Qq description
+.Dq description

 is the manual's short description.
 If an architecture is specified for the manual, it is displayed as
 is the manual's short description.
 If an architecture is specified for the manual, it is displayed as

-.Qq title(cat/arch) \- description .
+.Pp
+.D1 name(sec/arch) \- description
+.Pp
+Resulting manuals may be accessed as
+.Pp
+.Dl $ man \-s sec name
+.Pp
+If an architecture is specified in the output, use
+.Pp
+.Dl $ man \-s sec \-S arch name

 .Ss Macro Keys
 Queries evaluate over a subset of
 .Xr mdoc 7
 macros indexed by
 .Ss Macro Keys
 Queries evaluate over a subset of
 .Xr mdoc 7
 macros indexed by

-.Xr mandocdb 8 .
+.Xr makewhatis 8 .

 In addition to the macro keys listed below, the special key
 .Cm any
 may be used to match any available macro key.
 In addition to the macro keys listed below, the special key
 .Cm any
 may be used to match any available macro key.


@@ -125,6 +247,8 @@ Names and description:
 .Bl -column "xLix" description -offset indent -compact
 .It Li \&Nm Ta manual name
 .It Li \&Nd Ta one-line manual description
 .Bl -column "xLix" description -offset indent -compact
 .It Li \&Nm Ta manual name
 .It Li \&Nd Ta one-line manual description

+.It Li arch Ta machine architecture (case-insensitive)
+.It Li sec  Ta manual section number

 .El
 .Pp
 Sections and cross references:
 .El
 .Pp
 Sections and cross references:


@@ -187,36 +311,72 @@ Text production:
 .It Li \&Ox Ta Ox No version reference
 .It Li \&Dx Ta Dx No version reference
 .El
 .It Li \&Ox Ta Ox No version reference
 .It Li \&Dx Ta Dx No version reference
 .El

+.Pp
+In general, macro keys are supposed to yield complete results without
+expecting the user to consider actual macro usage.
+For example, results include:
+.Pp
+.Bl -tag -width 3n -offset 3n -compact
+.It Li \&Fa
+function arguments appearing on
+.Ic \&Fn
+lines
+.It Li \&Fn
+function names marked up with
+.Ic \&Fo
+macros
+.It Li \&In
+include file names marked up with
+.Ic \&Fd
+macros
+.It Li \&Vt
+types appearing as function return types and
+.It \&
+types appearing in function arguments in the SYNOPSIS
+.El

 .Sh ENVIRONMENT
 .Sh ENVIRONMENT

-.Bl -tag -width Ds
+.Bl -tag -width MANPAGER
+.It Ev MANPAGER
+Any non-empty value of the environment variable
+.Ev MANPAGER
+is used instead of the standard pagination program,
+.Xr less 1 ;
+see
+.Xr man 1
+for details.
+Only used if
+.Fl a
+or
+.Fl l
+is specified.

 .It Ev MANPATH
 .It Ev MANPATH

-Colon-separated paths modifying the default list of paths searched for
-manual databases.
-Invalid paths, or paths without manual databases, are ignored.
+A colon-separated list of directories to search for manual pages; see
+.Xr man 1
+for details.

 Overridden by
 Overridden by

-.Fl M .
-If
-.Ev MANPATH
-begins with a
-.Sq \&: ,
-it is appended to the default list;
-else if it ends with
-.Sq \&: ,
-it is prepended to the default list; else if it contains
-.Sq \&:: ,
-the default list is inserted between the colons.
-If none of these conditions are met, it overrides the default list.
+.Fl M ,
+ignored if
+.Fl l
+is specified.
+.It Ev PAGER
+Specifies the pagination program to use when
+.Ev MANPAGER
+is not defined.
+If neither PAGER nor MANPAGER is defined,
+.Xr less 1
+is used.
+Only used if
+.Fl a
+or
+.Fl l
+is specified.

 .El
 .Sh FILES
 .Bl -tag -width "/etc/man.conf" -compact
 .El
 .Sh FILES
 .Bl -tag -width "/etc/man.conf" -compact

-.It Pa whatis.db
+.It Pa mandoc.db

 name of the
 name of the

-.Xr mandocdb 8
+.Xr makewhatis 8

 keyword database
 keyword database

-.It Pa whatis.index
-name of the
-.Xr mandocdb 8
-filename database

 .It Pa /etc/man.conf
 default
 .Xr man 1
 .It Pa /etc/man.conf
 default
 .Xr man 1


@@ -226,35 +386,128 @@ configuration file
 .Ex -std
 .Sh EXAMPLES
 Search for
 .Ex -std
 .Sh EXAMPLES
 Search for

-.Qq mdoc
-as a word or
-.Xr glob 7
-expression:
+.Qq .cf
+as a substring of manual names and descriptions:

 .Pp
 .Pp

-.Dl $ apropos mdoc
-.Dl $ apropos any~mdoc*
+.Dl $ apropos =.cf

 .Pp
 Include matches for
 .Pp
 Include matches for

-.Qq roff
+.Qq .cnf

 and
 and

-.Qq man
-using
-.Xr glob 7
-expressions:
+.Qq .conf
+as well:

 .Pp
 .Pp

-.Dl $ apropos ~*mdoc* ~*roff*
+.Dl $ apropos =.cf =.cnf =.conf

 .Pp
 .Pp

-Search for
+Search in names and descriptions using a case-sensitive regular expression:
+.Pp
+.Dl $ apropos \(aq\(tiset.?[ug]id\(aq
+.Pp
+Search for all manual pages in a given section:
+.Pp
+.Dl $ apropos \-s 9 \&.
+.Pp
+Search for manuals in the library section mentioning both the
+.Qq optind
+and the

 .Qq optarg
 .Qq optarg

-as a variable name in the library category:
+variables:
+.Pp
+.Dl $ apropos \-s 3 Va=optind \-a Va=optarg

 .Pp
 .Pp

-.Dl $ apropos \-s 3 Va=optarg
+Do exactly the same as calling
+.Nm whatis
+with the argument
+.Qq ssh :
+.Pp
+.Dl $ apropos \-\- \-i \(aqNm\(ti[[:<:]]ssh[[:>:]]\(aq
+.Pp
+The following two invocations are equivalent:
+.Pp
+.D1 Li $ apropos -S Ar arch Li -s Ar section expression
+.Bd -ragged -offset indent
+.Li $ apropos \e( Ar expression Li \e)
+.Li -a arch\(ti^( Ns Ar arch Ns Li |any)$
+.Li -a sec\(ti^ Ns Ar section Ns Li $
+.Ed

 .Sh SEE ALSO
 .Sh SEE ALSO

-.Xr glob 7 ,
-.Xr mandocdb 8
-.Sh AUTHORS
+.Xr man 1 ,
+.Xr re_format 7 ,
+.Xr makewhatis 8
+.Sh STANDARDS
+The
+.Nm
+utility is compliant with the
+.St -p1003.1-2008
+specification of
+.Xr man 1
+.Fl k .
+.Pp
+All options, the
+.Nm whatis
+command, support for logical operators, macro keys,
+substring matching, sorting of results, the environment variables
+.Ev MANPAGER
+and
+.Ev MANPATH ,
+the database format, and the configuration file
+are extensions to that specification.
+.Sh HISTORY
+Part of the functionality of
+.Nm whatis
+was already provided by the former
+.Nm manwhere
+utility in
+.Bx 1 .

 The
 .Nm
 The
 .Nm

-utility was written by
-.An Kristaps Dzonsons ,
-.Mt kristaps@bsd.lv .
+and
+.Nm whatis
+utilities first appeared in
+.Bx 2 .
+They were rewritten from scratch for
+.Ox 5.6 .
+.Pp
+The
+.Fl M
+option and the
+.Ev MANPATH
+variable first appeared in
+.Bx 4.3 ;
+.Fl m
+in
+.Bx 4.3 Reno ;
+.Fl C
+in
+.Bx 4.4 Lite1 ;
+and
+.Fl S
+and
+.Fl s
+in
+.Ox 4.5
+for
+.Nm
+and in
+.Ox 5.6
+for
+.Nm whatis .
+The options
+.Fl acfhIKklOTWw
+appeared in
+.Ox 5.7 .
+.Sh AUTHORS
+.An -nosplit
+.An Bill Joy
+wrote
+.Nm manwhere
+in 1977 and the original
+.Bx
+.Nm
+and
+.Nm whatis
+in February 1979.
+The current version was written by
+.An Kristaps Dzonsons Aq Mt kristaps@bsd.lv
+and
+.An Ingo Schwarze Aq Mt schwarze@openbsd.org .