1 /*	$OpenBSD: strsep.c,v 1.6 2005/08/08 08:05:37 espie Exp $	*/
2 
3 /*-
4  * Copyright (c) 1990, 1993
5  *	The Regents of the University of California.  All rights reserved.
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 
32 #include <string.h>
33 #include <stdio.h>
34 
35 /*
36  * Get next token from string *stringp, where tokens are possibly-empty
37  * strings separated by characters from delim.
38  *
39  * Writes NULs into the string at *stringp to end tokens.
40  * delim need not remain constant from call to call.
41  * On return, *stringp points past the last NUL written (if there might
42  * be further tokens), or is NULL (if there are definitely no more tokens).
43  *
44  * If *stringp is NULL, strsep returns NULL.
45  */
46 char *
47 strsep(char **stringp, const char *delim)
48 {
49 	char *s;
50 	const char *spanp;
51 	int c, sc;
52 	char *tok;
53 
54 	if ((s = *stringp) == NULL)
55 		return (NULL);
56 	for (tok = s;;) {
57 		c = *s++;
58 		spanp = delim;
59 		do {
60 			if ((sc = *spanp++) == c) {
61 				if (c == 0)
62 					s = NULL;
63 				else
64 					s[-1] = 0;
65 				*stringp = s;
66 				return (tok);
67 			}
68 		} while (sc != 0);
69 	}
70 	/* NOTREACHED */
71 }