1 /*	$NetBSD: stresep.c,v 1.2 2007/12/06 22:07:07 seb 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 <sys/cdefs.h>
33 #if defined(LIBC_SCCS) && !defined(lint)
34 #if 0
35 static char sccsid[] = "@(#)strsep.c	8.1 (Berkeley) 6/4/93";
36 #else
37 __RCSID("$NetBSD: stresep.c,v 1.2 2007/12/06 22:07:07 seb Exp $");
38 #endif
39 #endif /* LIBC_SCCS and not lint */
40 
41 #include "namespace.h"
42 
43 #include <assert.h>
44 #include <string.h>
45 
46 #ifdef __weak_alias
__weak_alias(stresep,_stresep)47 __weak_alias(stresep,_stresep)
48 #endif
49 
50 /*
51  * Get next token from string *stringp, where tokens are possibly-empty
52  * strings separated by characters from delim. If esc is not NUL, then
53  * the characters followed by esc are ignored and are not taken into account
54  * when splitting the string.
55  *
56  * Writes NULs into the string at *stringp to end tokens.
57  * delim need not remain constant from call to call.
58  * On return, *stringp points past the last NUL written (if there might
59  * be further tokens), or is NULL (if there are definitely no more tokens).
60  *
61  * If *stringp is NULL, stresep returns NULL.
62  */
63 char *
64 stresep(char **stringp, const char *delim, int esc)
65 {
66 	char *s;
67 	const char *spanp;
68 	int c, sc;
69 	char *tok;
70 
71 	_DIAGASSERT(stringp != NULL);
72 	_DIAGASSERT(delim != NULL);
73 
74 	if ((s = *stringp) == NULL)
75 		return NULL;
76 	for (tok = s;;) {
77 		c = *s++;
78 		while (esc != '\0' && c == esc) {
79 			(void)strcpy(s - 1, s);
80 			c = *s++;
81 		}
82 		spanp = delim;
83 		do {
84 			if ((sc = *spanp++) == c) {
85 				if (c == 0)
86 					s = NULL;
87 				else
88 					s[-1] = 0;
89 				*stringp = s;
90 				return tok;
91 			}
92 		} while (sc != 0);
93 	}
94 }
95