freebsd-dev/lib/libc/string/strlen.3

.\" Copyright (c) 1990, 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" Chris Torek and the American National Standards Committee X3,
.\" on Information Processing Systems.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
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.\"     @(#)strlen.3	8.1 (Berkeley) 6/4/93
.\" $FreeBSD$
.\"
.Dd February 28, 2009
.Dt STRLEN 3
.Os
.Sh NAME
.Nm strlen, strnlen
.Nd find length of string
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In string.h
.Ft size_t
.Fn strlen "const char *s"
.Ft size_t
.Fn strnlen "const char *s" "size_t maxlen"
.Sh DESCRIPTION
The
.Fn strlen
function
computes the length of the string
.Fa s .
The
.Fn strnlen
function attempts to compute the length of
.Fa s ,
but never scans beyond the first
.Fa maxlen
bytes of
.Fa s .
.Sh RETURN VALUES
The
.Fn strlen
function
returns
the number of characters that precede the
terminating
.Dv NUL
character.
The
.Fn strnlen
function returns either the same result as
.Fn strlen
or
.Fa maxlen ,
whichever is smaller.
.Sh SEE ALSO
.Xr string 3 ,
.Xr wcslen 3 ,
.Xr wcswidth 3
.Sh STANDARDS
The
.Fn strlen
function
conforms to
.St -isoC .
The
.Fn strnlen
function conforms to
.St -p1003.1-2008 .
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.\" Copyright (c) 1990, 1991, 1993`
			`.\" The Regents of the University of California. All rights reserved.`
			`.\"`
			`.\" This code is derived from software contributed to Berkeley by`
			`.\" Chris Torek and the American National Standards Committee X3,`
			`.\" on Information Processing Systems.`
			`.\"`
			`.\" Redistribution and use in source and binary forms, with or without`
			`.\" modification, are permitted provided that the following conditions`
			`.\" are met:`
			`.\" 1. Redistributions of source code must retain the above copyright`
			`.\" notice, this list of conditions and the following disclaimer.`
			`.\" 2. Redistributions in binary form must reproduce the above copyright`
			`.\" notice, this list of conditions and the following disclaimer in the`
			`.\" documentation and/or other materials provided with the distribution.`
Renumber clauses to reduce diffs to other versions NetBSD, OpenBSD, and Android's Bionic number the clauses 1 through 3, so follow suit to make comparison easier. 2013-05-28 20:57:40 +00:00			`.\" 3. Neither the name of the University nor the names of its contributors`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.\" may be used to endorse or promote products derived from this software`
			`.\" without specific prior written permission.`
			`.\"`
			.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
			`.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE`
			`.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE`
			`.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE`
			`.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL`
			`.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS`
			`.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)`
			`.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT`
			`.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY`
			`.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF`
			`.\" SUCH DAMAGE.`
			`.\"`
			`.\" @(#)strlen.3 8.1 (Berkeley) 6/4/93`
$Id$ -> $FreeBSD$ 1999-08-28 00:22:10 +00:00			`.\" $FreeBSD$`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.\"`
- Add getdelim(), getline(), stpncpy(), strnlen(), wcsnlen(), wcscasecmp(), and wcsncasecmp(). - Make some previously non-standard extensions visible if POSIX_VISIBLE >= 200809. - Use restrict qualifiers in stpcpy(). - Declare off_t and size_t in stdio.h. - Bump __FreeBSD_version in case the new symbols (particularly getline()) cause issues with ports. Reviewed by: standards@ 2009-02-28 06:00:58 +00:00			`.Dd February 28, 2009`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Dt STRLEN 3`
			`.Os`
			`.Sh NAME`
- Add getdelim(), getline(), stpncpy(), strnlen(), wcsnlen(), wcscasecmp(), and wcsncasecmp(). - Make some previously non-standard extensions visible if POSIX_VISIBLE >= 200809. - Use restrict qualifiers in stpcpy(). - Declare off_t and size_t in stdio.h. - Bump __FreeBSD_version in case the new symbols (particularly getline()) cause issues with ports. Reviewed by: standards@ 2009-02-28 06:00:58 +00:00			`.Nm strlen, strnlen`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Nd find length of string`
Introduce ".Lb" macro to libc manpages. More libraries manpages updates following. 2000-04-21 09:42:15 +00:00			`.Sh LIBRARY`
			`.Lb libc`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Sh SYNOPSIS`
mdoc(7) police: Use the new .In macro for #include statements. 2001-10-01 16:09:29 +00:00			`.In string.h`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Ft size_t`
			`.Fn strlen "const char *s"`
- Add getdelim(), getline(), stpncpy(), strnlen(), wcsnlen(), wcscasecmp(), and wcsncasecmp(). - Make some previously non-standard extensions visible if POSIX_VISIBLE >= 200809. - Use restrict qualifiers in stpcpy(). - Declare off_t and size_t in stdio.h. - Bump __FreeBSD_version in case the new symbols (particularly getline()) cause issues with ports. Reviewed by: standards@ 2009-02-28 06:00:58 +00:00			`.Ft size_t`
			`.Fn strnlen "const char *s" "size_t maxlen"`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Sh DESCRIPTION`
			`The`
			`.Fn strlen`
			`function`
			`computes the length of the string`
			`.Fa s .`
- Add getdelim(), getline(), stpncpy(), strnlen(), wcsnlen(), wcscasecmp(), and wcsncasecmp(). - Make some previously non-standard extensions visible if POSIX_VISIBLE >= 200809. - Use restrict qualifiers in stpcpy(). - Declare off_t and size_t in stdio.h. - Bump __FreeBSD_version in case the new symbols (particularly getline()) cause issues with ports. Reviewed by: standards@ 2009-02-28 06:00:58 +00:00			`The`
			`.Fn strnlen`
			`function attempts to compute the length of`
			`.Fa s ,`
			`but never scans beyond the first`
			`.Fa maxlen`
			`bytes of`
			`.Fa s .`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Sh RETURN VALUES`
			`The`
			`.Fn strlen`
			`function`
			`returns`
			`the number of characters that precede the`
			`terminating`
			`.Dv NUL`
			`character.`
- Add getdelim(), getline(), stpncpy(), strnlen(), wcsnlen(), wcscasecmp(), and wcsncasecmp(). - Make some previously non-standard extensions visible if POSIX_VISIBLE >= 200809. - Use restrict qualifiers in stpcpy(). - Declare off_t and size_t in stdio.h. - Bump __FreeBSD_version in case the new symbols (particularly getline()) cause issues with ports. Reviewed by: standards@ 2009-02-28 06:00:58 +00:00			`The`
			`.Fn strnlen`
			`function returns either the same result as`
			`.Fn strlen`
			`or`
			`.Fa maxlen ,`
			`whichever is smaller.`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Sh SEE ALSO`
Add wide character variants of string manipulations routines to 'SEE ALSO'. Approved by: rwatson (mentor) 2009-04-07 13:42:53 +00:00			`.Xr string 3 ,`
			`.Xr wcslen 3 ,`
			`.Xr wcswidth 3`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Sh STANDARDS`
			`The`
			`.Fn strlen`
			`function`
			`conforms to`
.St -ansiC -> .St -isoC 2001-02-26 13:23:47 +00:00			`.St -isoC .`
- Add getdelim(), getline(), stpncpy(), strnlen(), wcsnlen(), wcscasecmp(), and wcsncasecmp(). - Make some previously non-standard extensions visible if POSIX_VISIBLE >= 200809. - Use restrict qualifiers in stpcpy(). - Declare off_t and size_t in stdio.h. - Bump __FreeBSD_version in case the new symbols (particularly getline()) cause issues with ports. Reviewed by: standards@ 2009-02-28 06:00:58 +00:00			`The`
			`.Fn strnlen`
			`function conforms to`
			`.St -p1003.1-2008 .`