1.\" $OpenBSD: strsep.3,v 1.12 2007/05/31 19:19:32 jmc Exp $ 2.\" 3.\" Copyright (c) 1990, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" This code is derived from software contributed to Berkeley by 7.\" Chris Torek. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 3. Neither the name of the University nor the names of its contributors 18.\" may be used to endorse or promote products derived from this software 19.\" without specific prior written permission. 20.\" 21.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31.\" SUCH DAMAGE. 32.\" 33.\" @(#)strsep.3 8.1 (Berkeley) 6/9/93 34.\" 35.Dd $Mdocdate: May 31 2007 $ 36.Dt STRSEP 3 37.Os 38.Sh NAME 39.Nm strsep 40.Nd separate strings 41.Sh SYNOPSIS 42.Fd #include <string.h> 43.Ft char * 44.Fn strsep "char **stringp" "const char *delim" 45.Sh DESCRIPTION 46The 47.Fn strsep 48function locates, in the string referenced by 49.Fa *stringp , 50the first occurrence of any character in the string 51.Fa delim 52(or the terminating 53.Ql \e0 54character) and replaces it with a 55.Ql \e0 . 56The location of the next character after the delimiter character 57(or 58.Dv NULL , 59if the end of the string was reached) is stored in 60.Fa *stringp . 61The original value of 62.Fa *stringp 63is returned. 64.Pp 65An 66.Dq empty 67field, i.e., one caused by two adjacent delimiter characters, 68can be detected by comparing the location referenced by the pointer returned 69by 70.Fn strsep 71to 72.Ql \e0 . 73.Pp 74If 75.Fa *stringp 76is initially 77.Dv NULL , 78.Fn strsep 79returns 80.Dv NULL . 81.Sh EXAMPLES 82The following uses 83.Fn strsep 84to parse a string, containing tokens delimited by whitespace, into an 85argument vector: 86.Bd -literal -offset indent 87char **ap, *argv[10], *inputstring; 88 89for (ap = argv; ap < &argv[9] && 90 (*ap = strsep(&inputstring, " \et")) != NULL;) { 91 if (**ap != '\e0') 92 ap++; 93} 94*ap = NULL; 95.Ed 96.Sh HISTORY 97The 98.Fn strsep 99function is intended as a replacement for the 100.Fn strtok 101function. 102While the 103.Fn strtok 104function should be preferred for portability reasons (it conforms to 105.St -ansiC ) 106it is unable to handle empty fields, i.e., detect fields delimited by 107two adjacent delimiter characters, or to be used for more than a single 108string at a time. 109The 110.Fn strsep 111function first appeared in 112.Bx 4.4 . 113