[apple/libc.git] / string / FreeBSD / 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.
.\" 4. 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.
.\"
.\"     @(#)strlen.3	8.1 (Berkeley) 6/4/93
.\" $FreeBSD: src/lib/libc/string/strlen.3,v 1.9 2009/04/07 13:42:53 trasz Exp $
.\"
.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 .
Commit	Line	Data
5b2abdfb	1	.\" Copyright (c) 1990, 1991, 1993
e9ce8d39 A	2	.\" The Regents of the University of California. All rights reserved.
e9ce8d39 A	3	.\"
5b2abdfb A	4	.\" This code is derived from software contributed to Berkeley by
	5	.\" Chris Torek and the American National Standards Committee X3,
	6	.\" on Information Processing Systems.
	7	.\"
e9ce8d39 A	8	.\" Redistribution and use in source and binary forms, with or without
	9	.\" modification, are permitted provided that the following conditions
	10	.\" are met:
	11	.\" 1. Redistributions of source code must retain the above copyright
	12	.\" notice, this list of conditions and the following disclaimer.
	13	.\" 2. Redistributions in binary form must reproduce the above copyright
	14	.\" notice, this list of conditions and the following disclaimer in the
	15	.\" documentation and/or other materials provided with the distribution.
e9ce8d39 A	16	.\" 4. Neither the name of the University nor the names of its contributors
	17	.\" may be used to endorse or promote products derived from this software
	18	.\" without specific prior written permission.
	19	.\"
	20	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	21	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	22	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	23	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	24	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	25	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	26	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	27	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	28	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	29	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	30	.\" SUCH DAMAGE.
	31	.\"
5b2abdfb	32	.\" @(#)strlen.3 8.1 (Berkeley) 6/4/93
1f2f436a	33	.\" $FreeBSD: src/lib/libc/string/strlen.3,v 1.9 2009/04/07 13:42:53 trasz Exp $
e9ce8d39	34	.\"
1f2f436a	35	.Dd February 28, 2009
5b2abdfb	36	.Dt STRLEN 3
e9ce8d39 A	37	.Os
e9ce8d39 A	38	.Sh NAME
1f2f436a	39	.Nm strlen, strnlen
5b2abdfb	40	.Nd find length of string
e9ce8d39 A	41	.Sh LIBRARY
	42	.Lb libc
	43	.Sh SYNOPSIS
5b2abdfb A	44	.In string.h
	45	.Ft size_t
	46	.Fn strlen "const char *s"
1f2f436a A	47	.Ft size_t
1f2f436a A	48	.Fn strnlen "const char *s" "size_t maxlen"
e9ce8d39 A	49	.Sh DESCRIPTION
e9ce8d39 A	50	The
5b2abdfb A	51	.Fn strlen
	52	function
	53	computes the length of the string
	54	.Fa s .
1f2f436a A	55	The
	56	.Fn strnlen
	57	function attempts to compute the length of
	58	.Fa s ,
	59	but never scans beyond the first
	60	.Fa maxlen
	61	bytes of
	62	.Fa s .
e9ce8d39	63	.Sh RETURN VALUES
5b2abdfb A	64	The
	65	.Fn strlen
	66	function
	67	returns
	68	the number of characters that precede the
	69	terminating
	70	.Dv NUL
	71	character.
1f2f436a A	72	The
	73	.Fn strnlen
	74	function returns either the same result as
	75	.Fn strlen
	76	or
	77	.Fa maxlen ,
	78	whichever is smaller.
e9ce8d39	79	.Sh SEE ALSO
1f2f436a A	80	.Xr string 3 ,
	81	.Xr wcslen 3 ,
	82	.Xr wcswidth 3
5b2abdfb	83	.Sh STANDARDS
e9ce8d39	84	The
5b2abdfb A	85	.Fn strlen
	86	function
	87	conforms to
	88	.St -isoC .
1f2f436a A	89	The
	90	.Fn strnlen
	91	function conforms to
	92	.St -p1003.1-2008 .