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.Dd May 28, 2018 32.Dt STRSEP 3 33.Os 34.Sh NAME 35.Nm strsep 36.Nd separate strings 37.Sh LIBRARY 38.Lb libc 39.Sh SYNOPSIS 40.In string.h 41.Ft char * 42.Fn strsep "char **stringp" "const char *delim" 43.Sh DESCRIPTION 44The 45.Fn strsep 46function locates, in the string referenced by 47.Fa *stringp , 48the first occurrence of any character in the string 49.Fa delim 50(or the terminating 51.Ql \e0 52character) and replaces it with a 53.Ql \e0 . 54The location of the next character after the delimiter character 55(or NULL, if the end of the string was reached) is stored in 56.Fa *stringp . 57The original value of 58.Fa *stringp 59is returned. 60.Pp 61An 62.Dq empty 63field (i.e., a character in the string 64.Fa delim 65occurs as the first character of 66.Fa *stringp ) 67can be detected by comparing the location referenced by the returned pointer 68to 69.Ql \e0 . 70.Pp 71If 72.Fa *stringp 73is initially 74.Dv NULL , 75.Fn strsep 76returns 77.Dv NULL . 78.Sh EXAMPLES 79The following uses 80.Fn strsep 81to parse a string, and prints each token in separate line: 82.Bd -literal -offset indent 83char *token, *string, *tofree; 84 85tofree = string = strdup("abc,def,ghi"); 86if (string == NULL) 87 err(1, "strdup"); 88while ((token = strsep(&string, ",")) != NULL) 89 printf("%s\en", token); 90 91free(tofree); 92.Ed 93.Pp 94The following uses 95.Fn strsep 96to parse a string, containing tokens delimited by white space, into an 97argument vector: 98.Bd -literal -offset indent 99char **ap, *argv[10], *inputstring; 100 101for (ap = argv; (*ap = strsep(&inputstring, " \et")) != NULL;) 102 if (**ap != '\e0') 103 if (++ap >= &argv[10]) 104 break; 105.Ed 106.Sh SEE ALSO 107.Xr memchr 3 , 108.Xr strchr 3 , 109.Xr strcspn 3 , 110.Xr strpbrk 3 , 111.Xr strrchr 3 , 112.Xr strspn 3 , 113.Xr strstr 3 , 114.Xr strtok 3 115.Sh HISTORY 116The 117.Fn strsep 118function 119is intended as a replacement for the 120.Fn strtok 121function. 122While the 123.Fn strtok 124function should be preferred for portability reasons (it conforms to 125.St -isoC ) 126it is unable to handle empty fields, i.e., detect fields delimited by 127two adjacent delimiter characters, or to be used for more than a single 128string at a time. 129The 130.Fn strsep 131function first appeared in 132.Bx 4.4 . 133