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