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.\" 4. Neither the name of Softweyr LLC, the University nor the names 26.\" of its contributors may be used to endorse or promote products 27.\" derived from this software without specific prior written 28.\" permission. 29.\" 30.\" THIS SOFTWARE IS PROVIDED BY SOFTWEYR LLC, THE REGENTS AND 31.\" CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, 32.\" INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 33.\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 34.\" DISCLAIMED. IN NO EVENT SHALL SOFTWEYR LLC, THE REGENTS, OR 35.\" CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 36.\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 37.\" LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 38.\" USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 39.\" ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 40.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 41.\" OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 42.\" SUCH DAMAGE. 43.\" 44.\" @(#)strtok.3 8.2 (Berkeley) 2/3/94 45.\" $FreeBSD: src/lib/libc/string/strtok.3,v 1.26 2007/12/12 18:33:06 wes Exp $ 46.\" $DragonFly: src/lib/libc/string/strtok.3,v 1.4 2006/02/17 19:35:06 swildner Exp $ 47.\" 48.Dd November 27, 1998 49.Dt STRTOK 3 50.Os 51.Sh NAME 52.Nm strtok , 53.Nm strtok_r 54.Nd string tokens 55.Sh LIBRARY 56.Lb libc 57.Sh SYNOPSIS 58.In string.h 59.Ft char * 60.Fn strtok "char *str" "const char *sep" 61.Ft char * 62.Fn strtok_r "char *str" "const char *sep" "char **last" 63.Sh DESCRIPTION 64.Bf -symbolic 65This interface is obsoleted by 66.Xr strsep 3 . 67.Ef 68.Pp 69The 70.Fn strtok 71function 72is used to isolate sequential tokens in a null-terminated string, 73.Fa str . 74These tokens are separated in the string by at least one of the 75characters in 76.Fa sep . 77The first time that 78.Fn strtok 79is called, 80.Fa str 81should be specified; subsequent calls, wishing to obtain further tokens 82from the same string, should pass a null pointer instead. 83The separator string, 84.Fa sep , 85must be supplied each time, and may change between calls. 86.Pp 87The implementation will behave as if no library function calls 88.Fn strtok . 89.Pp 90The 91.Fn strtok_r 92function is a reentrant version of 93.Fn strtok . 94The context pointer 95.Fa last 96must be provided on each call. 97The 98.Fn strtok_r 99function 100may also be used to nest two parsing loops within one another, as 101long as separate context pointers are used. 102.Pp 103The 104.Fn strtok 105and 106.Fn strtok_r 107functions 108return a pointer to the beginning of each subsequent token in the string, 109after replacing the token itself with a 110.Dv NUL 111character. 112When no more tokens remain, a null pointer is returned. 113.Sh EXAMPLES 114The following uses 115.Fn strtok_r 116to parse two strings using separate contexts: 117.Bd -literal 118char test[80], blah[80]; 119char *sep = "\e\e/:;=-"; 120char *word, *phrase, *brkt, *brkb; 121 122strcpy(test, "This;is.a:test:of=the/string\e\etokenizer-function."); 123 124for (word = strtok_r(test, sep, &brkt); 125 word; 126 word = strtok_r(NULL, sep, &brkt)) 127{ 128 strcpy(blah, "blah:blat:blab:blag"); 129 130 for (phrase = strtok_r(blah, sep, &brkb); 131 phrase; 132 phrase = strtok_r(NULL, sep, &brkb)) 133 { 134 printf("So far we're at %s:%s\en", word, phrase); 135 } 136} 137.Ed 138.Sh SEE ALSO 139.Xr memchr 3 , 140.Xr strchr 3 , 141.Xr strcspn 3 , 142.Xr strpbrk 3 , 143.Xr strrchr 3 , 144.Xr strsep 3 , 145.Xr strspn 3 , 146.Xr strstr 3 , 147.Xr wcstok 3 148.Sh STANDARDS 149The 150.Fn strtok 151function 152conforms to 153.St -isoC . 154.Sh AUTHORS 155.An Wes Peters , 156Softweyr LLC: 157.Aq wes@softweyr.com 158.Pp 159Based on the 160.Fx 3.0 161implementation. 162.Sh BUGS 163The System V 164.Fn strtok , 165if handed a string containing only delimiter characters, 166will not alter the next starting point, so that a call to 167.Fn strtok 168with a different (or empty) delimiter string 169may return a 170.Pf non- Dv NULL 171value. 172Since this implementation always alters the next starting point, 173such a sequence of calls would always return 174.Dv NULL . 175