1.\" Copyright (c) 1988, 1991 The Regents of the University of California. 2.\" 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 5.8 (Berkeley) 6/29/91 37.\" $Id: strtok.3,v 1.4 1996/11/12 02:03:14 jtc Exp $ 38.\" 39.Dd June 29, 1991 40.Dt STRTOK 3 41.Os BSD 3 42.Sh NAME 43.Nm strtok , 44.Nm strsep 45.Nd string token operations 46.Sh SYNOPSIS 47.Fd #include <string.h> 48.Ft char * 49.Fn strtok "char *str" "const char *sep" 50.Ft char * 51.Fn strtok_r "char *str" "const char *sep" "char **lasts" 52.Sh DESCRIPTION 53.Bf -symbolic 54This interface is obsoleted by strsep(3). 55.Ef 56.Pp 57The 58.Fn strtok 59function 60is used to isolate sequential tokens in a null-terminated string, 61.Fa str . 62These tokens are separated in the string by at least one of the 63characters in 64.Fa sep . 65The first time that 66.Fn strtok 67is called, 68.Fa str 69should be specified; subsequent calls, wishing to obtain further tokens 70from the same string, should pass a null pointer instead. 71The separator string, 72.Fa sep , 73must be supplied each time, and may change between calls. 74.Pp 75The 76.Fn strtok 77function 78returns a pointer to the beginning of each subsequent token in the string, 79after replacing the separator character itself with a 80.Dv NUL 81character. 82When no more tokens remain, a null pointer is returned. 83.Sh SEE ALSO 84.Xr index 3 , 85.Xr memchr 3 , 86.Xr rindex 3 , 87.Xr strchr 3 , 88.Xr strcspn 3 , 89.Xr strpbrk 3 , 90.Xr strrchr 3 , 91.Xr strsep 3 , 92.Xr strspn 3 , 93.Xr strstr 3 94.Sh STANDARDS 95The 96.Fn strtok 97function 98conforms to 99.St -ansiC . 100.Sh BUGS 101There is no way to get tokens from multiple strings simultaneously. 102.Pp 103The System V 104.Fn strtok , 105if handed a string containing only delimiter characters, 106will not alter the next starting point, so that a call to 107.Fn strtok 108with a different (or empty) delimiter string 109may return a 110.Pf non- Dv NULL 111value. 112Since this implementation always alters the next starting point, 113such a sequence of calls would always return 114.Dv NULL . 115