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 1.1.1.1 1995/10/18 08:42:23 deraadt 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.Sh DESCRIPTION 51.Bf -symbolic 52This interface is obsoleted by strsep(3). 53.Ef 54.Pp 55The 56.Fn strtok 57function 58is used to isolate sequential tokens in a null-terminated string, 59.Fa str . 60These tokens are separated in the string by at least one of the 61characters in 62.Fa sep . 63The first time that 64.Fn strtok 65is called, 66.Fa str 67should be specified; subsequent calls, wishing to obtain further tokens 68from the same string, should pass a null pointer instead. 69The separator string, 70.Fa sep , 71must be supplied each time, and may change between calls. 72.Pp 73The 74.Fn strtok 75function 76returns a pointer to the beginning of each subsequent token in the string, 77after replacing the separator character itself with a 78.Dv NUL 79character. 80When no more tokens remain, a null pointer is returned. 81.Sh SEE ALSO 82.Xr index 3 , 83.Xr memchr 3 , 84.Xr rindex 3 , 85.Xr strchr 3 , 86.Xr strcspn 3 , 87.Xr strpbrk 3 , 88.Xr strrchr 3 , 89.Xr strsep 3 , 90.Xr strspn 3 , 91.Xr strstr 3 92.Sh STANDARDS 93The 94.Fn strtok 95function 96conforms to 97.St -ansiC . 98.Sh BUGS 99There is no way to get tokens from multiple strings simultaneously. 100.Pp 101The System V 102.Fn strtok , 103if handed a string containing only delimiter characters, 104will not alter the next starting point, so that a call to 105.Fn strtok 106with a different (or empty) delimiter string 107may return a 108.Pf non- Dv NULL 109value. 110Since this implementation always alters the next starting point, 111such a sequence of calls would always return 112.Dv NULL . 113