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.\" 33.Dd May 28, 2018 34.Dt STRSEP 3 35.Os 36.Sh NAME 37.Nm strsep 38.Nd separate strings 39.Sh LIBRARY 40.Lb libc 41.Sh SYNOPSIS 42.In 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 NULL, if the end of the string was reached) is stored in 58.Fa *stringp . 59The original value of 60.Fa *stringp 61is returned. 62.Pp 63An 64.Dq empty 65field (i.e., a character in the string 66.Fa delim 67occurs as the first character of 68.Fa *stringp ) 69can be detected by comparing the location referenced by the returned pointer 70to 71.Ql \e0 . 72.Pp 73If 74.Fa *stringp 75is initially 76.Dv NULL , 77.Fn strsep 78returns 79.Dv NULL . 80.Sh EXAMPLES 81The following uses 82.Fn strsep 83to parse a string, and prints each token in separate line: 84.Bd -literal -offset indent 85char *token, *string, *tofree; 86 87tofree = string = strdup("abc,def,ghi"); 88if (string == NULL) 89 err(1, "strdup"); 90while ((token = strsep(&string, ",")) != NULL) 91 printf("%s\en", token); 92 93free(tofree); 94.Ed 95.Pp 96The following uses 97.Fn strsep 98to parse a string, containing tokens delimited by white space, into an 99argument vector: 100.Bd -literal -offset indent 101char **ap, *argv[10], *inputstring; 102 103for (ap = argv; (*ap = strsep(&inputstring, " \et")) != NULL;) 104 if (**ap != '\e0') 105 if (++ap >= &argv[10]) 106 break; 107.Ed 108.Sh SEE ALSO 109.Xr memchr 3 , 110.Xr strchr 3 , 111.Xr strcspn 3 , 112.Xr strpbrk 3 , 113.Xr strrchr 3 , 114.Xr strspn 3 , 115.Xr strstr 3 , 116.Xr strtok 3 117.Sh HISTORY 118The 119.Fn strsep 120function 121is intended as a replacement for the 122.Fn strtok 123function. 124While the 125.Fn strtok 126function should be preferred for portability reasons (it conforms to 127.St -isoC ) 128it is unable to handle empty fields, i.e., detect fields delimited by 129two adjacent delimiter characters, or to be used for more than a single 130string at a time. 131The 132.Fn strsep 133function first appeared in 134.Bx 4.4 . 135