1.\" Copyright (c) 1988, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" the American National Standards Committee X3, on Information 6.\" Processing Systems. 7.\" 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 3. All advertising materials mentioning features or use of this software 17.\" must display the following acknowledgement: 18.\" This product includes software developed by the University of 19.\" California, Berkeley and its contributors. 20.\" 4. Neither the name of the University nor the names of its contributors 21.\" may be used to endorse or promote products derived from this software 22.\" without specific prior written permission. 23.\" 24.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34.\" SUCH DAMAGE. 35.\" 36.\" from: @(#)strtok.3 8.2 (Berkeley) 2/3/94 37.\" $NetBSD: strtok.3,v 1.10 1999/03/22 19:44:59 garbled Exp $ 38.\" 39.Dd February 3, 1994 40.Dt STRTOK 3 41.Os 42.Sh NAME 43.Nm strtok, strtok_r 44.Nd string tokens 45.Sh LIBRARY 46.Lb libc 47.Sh SYNOPSIS 48.Fd #include <string.h> 49.Ft char * 50.Fn strtok "char *str" "const char *sep" 51.Ft char * 52.Fn strtok_r "char *str" "const char *sep" "char **lasts" 53.Sh DESCRIPTION 54.Bf -symbolic 55This interface is obsoleted by 56.Xr strsep 3 . 57.Ef 58.Pp 59The 60.Fn strtok 61function 62is used to isolate sequential tokens in a null-terminated string, 63.Fa str . 64These tokens are separated in the string by at least one of the 65characters in 66.Fa sep . 67The first time that 68.Fn strtok 69is called, 70.Fa str 71should be specified; subsequent calls, wishing to obtain further tokens 72from the same string, should pass a null pointer instead. 73The separator string, 74.Fa sep , 75must be supplied each time, and may change between calls. 76.Pp 77The 78.Fn strtok 79function 80returns a pointer to the beginning of each subsequent token in the string, 81after replacing the separator character itself with a 82.Dv NUL 83character. 84When no more tokens remain, a null pointer is returned. 85.Sh SEE ALSO 86.Xr index 3 , 87.Xr memchr 3 , 88.Xr rindex 3 , 89.Xr strchr 3 , 90.Xr strcspn 3 , 91.Xr strpbrk 3 , 92.Xr strrchr 3 , 93.Xr strsep 3 , 94.Xr strspn 3 , 95.Xr strstr 3 96.Sh STANDARDS 97The 98.Fn strtok 99function 100conforms to 101.St -ansiC . 102The 103.Fn strtok_r 104function conforms to 105.St -p1003.1c-95 . 106.Sh BUGS 107There is no way to get tokens from multiple strings simultaneously. 108.Pp 109The System V 110.Fn strtok , 111if handed a string containing only delimiter characters, 112will not alter the next starting point, so that a call to 113.Fn strtok 114with a different (or empty) delimiter string 115may return a 116.Pf non- Dv NULL 117value. 118Since this implementation always alters the next starting point, 119such a sequence of calls would always return 120.Dv NULL . 121