1.\" Copyright (c) 1990, 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.\" Chris Torek. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. Neither the name of the University nor the names of its contributors 16.\" may be used to endorse or promote products derived from this software 17.\" without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.\" @(#)strsep.3 8.1 (Berkeley) 6/9/93 32.\" $FreeBSD$ 33.\" 34.Dd December 5, 2008 35.Dt STRSEP 3 36.Os 37.Sh NAME 38.Nm strsep 39.Nd separate strings 40.Sh LIBRARY 41.Lb libc 42.Sh SYNOPSIS 43.In string.h 44.Ft char * 45.Fn strsep "char **stringp" "const char *delim" 46.Sh DESCRIPTION 47The 48.Fn strsep 49function locates, in the string referenced by 50.Fa *stringp , 51the first occurrence of any character in the string 52.Fa delim 53(or the terminating 54.Ql \e0 55character) and replaces it with a 56.Ql \e0 . 57The location of the next character after the delimiter character 58(or NULL, if the end of the string was reached) is stored in 59.Fa *stringp . 60The original value of 61.Fa *stringp 62is returned. 63.Pp 64An 65.Dq empty 66field (i.e., a character in the string 67.Fa delim 68occurs as the first character of 69.Fa *stringp ) 70can be detected by comparing the location referenced by the returned pointer 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, and prints each token in separate line: 85.Bd -literal -offset indent 86char *token, *string, *tofree; 87 88tofree = string = strdup("abc,def,ghi"); 89assert(string != NULL); 90 91while ((token = strsep(&string, ",")) != NULL) 92 printf("%s\en", token); 93 94free(tofree); 95.Ed 96.Pp 97The following uses 98.Fn strsep 99to parse a string, containing tokens delimited by white space, into an 100argument vector: 101.Bd -literal -offset indent 102char **ap, *argv[10], *inputstring; 103 104for (ap = argv; (*ap = strsep(&inputstring, " \et")) != NULL;) 105 if (**ap != '\e0') 106 if (++ap >= &argv[10]) 107 break; 108.Ed 109.Sh SEE ALSO 110.Xr memchr 3 , 111.Xr strchr 3 , 112.Xr strcspn 3 , 113.Xr strpbrk 3 , 114.Xr strrchr 3 , 115.Xr strspn 3 , 116.Xr strstr 3 , 117.Xr strtok 3 118.Sh HISTORY 119The 120.Fn strsep 121function 122is intended as a replacement for the 123.Fn strtok 124function. 125While the 126.Fn strtok 127function should be preferred for portability reasons (it conforms to 128.St -isoC ) 129it is unable to handle empty fields, i.e., detect fields delimited by 130two adjacent delimiter characters, or to be used for more than a single 131string at a time. 132The 133.Fn strsep 134function first appeared in 135.Bx 4.4 . 136