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.Dd January 22, 2016 45.Dt STRTOK 3 46.Os 47.Sh NAME 48.Nm strtok , strtok_r 49.Nd string tokens 50.Sh LIBRARY 51.Lb libc 52.Sh SYNOPSIS 53.In string.h 54.Ft char * 55.Fn strtok "char *str" "const char *sep" 56.Ft char * 57.Fn strtok_r "char *str" "const char *sep" "char **last" 58.Sh DESCRIPTION 59.Bf -symbolic 60This interface is obsoleted by 61.Xr strsep 3 . 62.Ef 63.Pp 64The 65.Fn strtok 66function 67is used to isolate sequential tokens in a null-terminated string, 68.Fa str . 69These tokens are separated in the string by at least one of the 70characters in 71.Fa sep . 72The first time that 73.Fn strtok 74is called, 75.Fa str 76should be specified; subsequent calls, wishing to obtain further tokens 77from the same string, should pass a null pointer instead. 78The separator string, 79.Fa sep , 80must be supplied each time, and may change between calls. 81.Pp 82The implementation will behave as if no library function calls 83.Fn strtok . 84.Pp 85The 86.Fn strtok_r 87function is a reentrant version of 88.Fn strtok . 89The context pointer 90.Fa last 91must be provided on each call. 92The 93.Fn strtok_r 94function 95may also be used to nest two parsing loops within one another, as 96long as separate context pointers are used. 97.Sh RETURN VALUES 98The 99.Fn strtok 100and 101.Fn strtok_r 102functions 103return a pointer to the beginning of each subsequent token in the string, 104after replacing the token itself with a 105.Dv NUL 106character. 107When no more tokens remain, a null pointer is returned. 108.Sh EXAMPLES 109The following uses 110.Fn strtok_r 111to parse two strings using separate contexts: 112.Bd -literal 113char test[80], blah[80]; 114char *sep = "\e\e/:;=-"; 115char *word, *phrase, *brkt, *brkb; 116 117strcpy(test, "This;is.a:test:of=the/string\e\etokenizer-function."); 118 119for (word = strtok_r(test, sep, &brkt); 120 word; 121 word = strtok_r(NULL, sep, &brkt)) 122{ 123 strcpy(blah, "blah:blat:blab:blag"); 124 125 for (phrase = strtok_r(blah, sep, &brkb); 126 phrase; 127 phrase = strtok_r(NULL, sep, &brkb)) 128 { 129 printf("So far we're at %s:%s\en", word, phrase); 130 } 131} 132.Ed 133.Sh SEE ALSO 134.Xr memchr 3 , 135.Xr strchr 3 , 136.Xr strcspn 3 , 137.Xr strpbrk 3 , 138.Xr strrchr 3 , 139.Xr strsep 3 , 140.Xr strspn 3 , 141.Xr strstr 3 , 142.Xr wcstok 3 143.Sh STANDARDS 144The 145.Fn strtok 146function 147conforms to 148.St -isoC . 149The 150.Fn strtok_r 151function 152conforms to 153.St -p1003.1-2001 . 154.Sh AUTHORS 155.An Wes Peters Aq Mt wes@softweyr.com , 156Softweyr LLC 157.Pp 158Based on the 159.Fx 3.0 160implementation. 161.Sh BUGS 162The System V 163.Fn strtok , 164if handed a string containing only delimiter characters, 165will not alter the next starting point, so that a call to 166.Fn strtok 167with a different (or empty) delimiter string 168may return a 169.Pf non- Dv NULL 170value. 171Since this implementation always alters the next starting point, 172such a sequence of calls would always return 173.Dv NULL . 174