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 71This interface is obsoleted by 72.Xr strsep 3 . 73.Ef 74.Pp 75The 76.Fn strtok 77function 78is used to isolate sequential tokens in a null-terminated string, 79.Fa str . 80These tokens are separated in the string by at least one of the 81characters in 82.Fa sep . 83The first time that 84.Fn strtok 85is called, 86.Fa str 87should be specified; subsequent calls, wishing to obtain further tokens 88from the same string, should pass a null pointer instead. 89The separator string, 90.Fa sep , 91must be supplied each time, and may change between calls. 92.Pp 93The implementation will behave as if no library function calls 94.Fn strtok . 95.Pp 96The 97.Fn strtok_r 98function is a reentrant version of 99.Fn strtok . 100The context pointer 101.Fa last 102must be provided on each call. 103.Fn strtok_r 104may also be used to nest two parsing loops within one another, as 105long as separate context pointers are used. 106.Pp 107The 108.Fn strtok 109and 110.Fn strtok_r 111functions 112return a pointer to the beginning of each subsequent token in the string, 113after replacing the token itself with a 114.Dv NUL 115character. 116When no more tokens remain, a null pointer is returned. 117.Sh EXAMPLES 118The following uses 119.Fn strtok_r 120to parse two strings using separate contexts: 121.Bd -literal 122char test[80], blah[80]; 123char *sep = "\e\e/:;=-"; 124char *word, *phrase, *brkt, *brkb; 125 126strcpy(test, "This;is.a:test:of=the/string\e\etokenizer-function."); 127 128for (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 152The 153.Fn strtok 154function 155conforms to 156.St -isoC . 157.Sh AUTHORS 158.An Wes Peters , 159Softweyr LLC: 160.Aq wes@softweyr.com 161.Pp 162Based on the 163.Fx 3.0 164implementation. 165.Sh BUGS 166The System V 167.Fn strtok , 168if handed a string containing only delimiter characters, 169will not alter the next starting point, so that a call to 170.Fn strtok 171with a different (or empty) delimiter string 172may return a 173.Pf non- Dv NULL 174value. 175Since this implementation always alters the next starting point, 176such a sequence of calls would always return 177.Dv NULL . 178