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. 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.\" $FreeBSD$ 46.\" 47.Dd January 22, 2016 48.Dt STRTOK 3 49.Os 50.Sh NAME 51.Nm strtok , strtok_r 52.Nd string tokens 53.Sh LIBRARY 54.Lb libc 55.Sh SYNOPSIS 56.In string.h 57.Ft char * 58.Fn strtok "char *str" "const char *sep" 59.Ft char * 60.Fn strtok_r "char *str" "const char *sep" "char **last" 61.Sh DESCRIPTION 62.Bf -symbolic 63This interface is obsoleted by 64.Xr strsep 3 . 65.Ef 66.Pp 67The 68.Fn strtok 69function 70is used to isolate sequential tokens in a null-terminated string, 71.Fa str . 72These tokens are separated in the string by at least one of the 73characters in 74.Fa sep . 75The first time that 76.Fn strtok 77is called, 78.Fa str 79should be specified; subsequent calls, wishing to obtain further tokens 80from the same string, should pass a null pointer instead. 81The separator string, 82.Fa sep , 83must be supplied each time, and may change between calls. 84.Pp 85The implementation will behave as if no library function calls 86.Fn strtok . 87.Pp 88The 89.Fn strtok_r 90function is a reentrant version of 91.Fn strtok . 92The context pointer 93.Fa last 94must be provided on each call. 95The 96.Fn strtok_r 97function 98may also be used to nest two parsing loops within one another, as 99long as separate context pointers are used. 100.Pp 101The 102.Fn strtok 103and 104.Fn strtok_r 105functions 106return a pointer to the beginning of each subsequent token in the string, 107after replacing the token itself with a 108.Dv NUL 109character. 110When no more tokens remain, a null pointer is returned. 111.Sh EXAMPLES 112The following uses 113.Fn strtok_r 114to parse two strings using separate contexts: 115.Bd -literal 116char test[80], blah[80]; 117char *sep = "\e\e/:;=-"; 118char *word, *phrase, *brkt, *brkb; 119 120strcpy(test, "This;is.a:test:of=the/string\e\etokenizer-function."); 121 122for (word = strtok_r(test, sep, &brkt); 123 word; 124 word = strtok_r(NULL, sep, &brkt)) 125{ 126 strcpy(blah, "blah:blat:blab:blag"); 127 128 for (phrase = strtok_r(blah, sep, &brkb); 129 phrase; 130 phrase = strtok_r(NULL, sep, &brkb)) 131 { 132 printf("So far we're at %s:%s\en", word, phrase); 133 } 134} 135.Ed 136.Sh SEE ALSO 137.Xr memchr 3 , 138.Xr strchr 3 , 139.Xr strcspn 3 , 140.Xr strpbrk 3 , 141.Xr strrchr 3 , 142.Xr strsep 3 , 143.Xr strspn 3 , 144.Xr strstr 3 , 145.Xr wcstok 3 146.Sh STANDARDS 147The 148.Fn strtok 149function 150conforms to 151.St -isoC . 152The 153.Fn strtok_r 154function 155conforms to 156.St -p1003.1-2001 . 157.Sh AUTHORS 158.An Wes Peters Aq Mt wes@softweyr.com , 159Softweyr LLC 160.Pp 161Based on the 162.Fx 3.0 163implementation. 164.Sh BUGS 165The System V 166.Fn strtok , 167if handed a string containing only delimiter characters, 168will not alter the next starting point, so that a call to 169.Fn strtok 170with a different (or empty) delimiter string 171may return a 172.Pf non- Dv NULL 173value. 174Since this implementation always alters the next starting point, 175such a sequence of calls would always return 176.Dv NULL . 177