gitweb.dragonflybsd.org Git - dragonfly.git/blame_incremental

... / ...

Commit	Line	Data
	1	.\" Copyright (c) 1998 Softweyr LLC. All rights reserved.
	2	.\"
	3	.\" strtok_r, from Berkeley strtok
	4	.\" Oct 13, 1998 by Wes Peters <wes@softweyr.com>
	5	.\"
	6	.\" Copyright (c) 1988, 1991, 1993
	7	.\" The Regents of the University of California. All rights reserved.
	8	.\"
	9	.\" This code is derived from software contributed to Berkeley by
	10	.\" the American National Standards Committee X3, on Information
	11	.\" Processing Systems.
	12	.\"
	13	.\" Redistribution and use in source and binary forms, with or without
	14	.\" modification, are permitted provided that the following conditions
	15	.\" are met:
	16	.\"
	17	.\" 1. Redistributions of source code must retain the above copyright
	18	.\" notices, this list of conditions and the following disclaimer.
	19	.\"
	20	.\" 2. Redistributions in binary form must reproduce the above
	21	.\" copyright notices, this list of conditions and the following
	22	.\" disclaimer in the documentation and/or other materials provided
	23	.\" with the distribution.
	24	.\"
	25	.\" 3. All advertising materials mentioning features or use of this
	26	.\" software must display the following acknowledgement:
	27	.\"
	28	.\" This product includes software developed by Softweyr LLC, the
	29	.\" University of California, Berkeley, and its contributors.
	30	.\"
	31	.\" 4. Neither the name of Softweyr LLC, the University nor the names
	32	.\" of its contributors may be used to endorse or promote products
	33	.\" derived from this software without specific prior written
	34	.\" permission.
	35	.\"
	36	.\" THIS SOFTWARE IS PROVIDED BY SOFTWEYR LLC, THE REGENTS AND
	37	.\" CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
	38	.\" INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
	39	.\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	40	.\" DISCLAIMED. IN NO EVENT SHALL SOFTWEYR LLC, THE REGENTS, OR
	41	.\" CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	42	.\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	43	.\" LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
	44	.\" USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
	45	.\" ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
	46	.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
	47	.\" OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	48	.\" SUCH DAMAGE.
	49	.\"
	50	.\" @(#)strtok.3 8.2 (Berkeley) 2/3/94
	51	.\" $FreeBSD: src/lib/libc/string/strtok.3,v 1.10.2.8 2001/12/14 18:33:59 ru Exp $
	52	.\" $DragonFly: src/lib/libc/string/strtok.3,v 1.4 2006/02/17 19:35:06 swildner Exp $
	53	.\"
	54	.Dd November 27, 1998
	55	.Dt STRTOK 3
	56	.Os
	57	.Sh NAME
	58	.Nm strtok ,
	59	.Nm strtok_r
	60	.Nd string tokens
	61	.Sh LIBRARY
	62	.Lb libc
	63	.Sh SYNOPSIS
	64	.In string.h
	65	.Ft char *
	66	.Fn strtok "char str" "const char sep"
	67	.Ft char *
	68	.Fn strtok_r "char str" "const char sep" "char **last"
	69	.Sh DESCRIPTION
	70	.Bf -symbolic
	71	This interface is obsoleted by
	72	.Xr strsep 3 .
	73	.Ef
	74	.Pp
	75	The
	76	.Fn strtok
	77	function
	78	is used to isolate sequential tokens in a null-terminated string,
	79	.Fa str .
	80	These tokens are separated in the string by at least one of the
	81	characters in
	82	.Fa sep .
	83	The first time that
	84	.Fn strtok
	85	is called,
	86	.Fa str
	87	should be specified; subsequent calls, wishing to obtain further tokens
	88	from the same string, should pass a null pointer instead.
	89	The separator string,
	90	.Fa sep ,
	91	must be supplied each time, and may change between calls.
	92	.Pp
	93	The implementation will behave as if no library function calls
	94	.Fn strtok .
	95	.Pp
	96	The
	97	.Fn strtok_r
	98	function is a reentrant version of
	99	.Fn strtok .
	100	The context pointer
	101	.Fa last
	102	must be provided on each call.
	103	.Fn strtok_r
	104	may also be used to nest two parsing loops within one another, as
	105	long as separate context pointers are used.
	106	.Pp
	107	The
	108	.Fn strtok
	109	and
	110	.Fn strtok_r
	111	functions
	112	return a pointer to the beginning of each subsequent token in the string,
	113	after replacing the token itself with a
	114	.Dv NUL
	115	character.
	116	When no more tokens remain, a null pointer is returned.
	117	.Sh EXAMPLES
	118	The following uses
	119	.Fn strtok_r
	120	to parse two strings using separate contexts:
	121	.Bd -literal
	122	char test[80], blah[80];
	123	char *sep = "\e\e/:;=-";
	124	char word, phrase, brkt, brkb;
	125
	126	strcpy(test, "This;is.a:test:of=the/string\e\etokenizer-function.");
	127
	128	for (word = strtok_r(test, sep, &brkt);
	129	word;
	130	word = strtok_r(NULL, sep, &brkt))
	131	{
	132	strcpy(blah, "blah:blat:blab:blag");
	133
	134	for (phrase = strtok_r(blah, sep, &brkb);
	135	phrase;
	136	phrase = strtok_r(NULL, sep, &brkb))
	137	{
	138	printf("So far we're at %s:%s\en", word, phrase);
	139	}
	140	}
	141	.Ed
	142	.Sh SEE ALSO
	143	.Xr memchr 3 ,
	144	.Xr strchr 3 ,
	145	.Xr strcspn 3 ,
	146	.Xr strpbrk 3 ,
	147	.Xr strrchr 3 ,
	148	.Xr strsep 3 ,
	149	.Xr strspn 3 ,
	150	.Xr strstr 3
	151	.Sh STANDARDS
	152	The
	153	.Fn strtok
	154	function
	155	conforms to
	156	.St -isoC .
	157	.Sh AUTHORS
	158	.An Wes Peters ,
	159	Softweyr LLC:
	160	.Aq wes@softweyr.com
	161	.Pp
	162	Based on the
	163	.Fx 3.0
	164	implementation.
	165	.Sh BUGS
	166	The System V
	167	.Fn strtok ,
	168	if handed a string containing only delimiter characters,
	169	will not alter the next starting point, so that a call to
	170	.Fn strtok
	171	with a different (or empty) delimiter string
	172	may return a
	173	.Pf non- Dv NULL
	174	value.
	175	Since this implementation always alters the next starting point,
	176	such a sequence of calls would always return
	177	.Dv NULL .