xref: /illumos-gate/usr/src/lib/libc/port/gen/strsep.c (revision b31b5de1357c915fe7dab4d9646d9d84f9fe69bc)
1 /*
2  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 /*	$OpenBSD: strsep.c,v 1.3 1997/08/20 04:28:14 millert Exp $	*/
7 
8 /*
9  * Copyright (c) 1990, 1993
10  *	The Regents of the University of California.  All rights reserved.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. All advertising materials mentioning features or use of this software
21  *    must display the following acknowledgement:
22  *	This product includes software developed by the University of
23  *	California, Berkeley and its contributors.
24  * 4. Neither the name of the University nor the names of its contributors
25  *    may be used to endorse or promote products derived from this software
26  *    without specific prior written permission.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38  * SUCH DAMAGE.
39  */
40 
41 #include "lint.h"
42 #include <string.h>
43 #include <stdio.h>
44 
45 #if defined(LIBC_SCCS) && !defined(lint)
46 #if 0
47 static char sccsid[] = "@(#)strsep.c	8.1 (Berkeley) 6/4/93";
48 #else
49 static char *rcsid =
50 	"$OpenBSD: strsep.c,v 1.3 1997/08/20 04:28:14 millert Exp $";
51 #endif
52 #endif /* LIBC_SCCS and not lint */
53 
54 /*
55  * Get next token from string *stringp, where tokens are possibly-empty
56  * strings separated by characters from delim.
57  *
58  * Writes NULs into the string at *stringp to end tokens.
59  * delim need not remain constant from call to call.
60  * On return, *stringp points past the last NUL written (if there might
61  * be further tokens), or is NULL (if there are definitely no more tokens).
62  *
63  * If *stringp is NULL, strsep returns NULL.
64  */
65 char *
66 strsep(char **stringp, const char *delim)
67 {
68 	register char *s;
69 	register const char *spanp;
70 	register int c, sc;
71 	char *tok;
72 
73 	if ((s = *stringp) == NULL)
74 		return (NULL);
75 	for (tok = s; ; ) {
76 		c = *s++;
77 		spanp = delim;
78 		do {
79 			if ((sc = *spanp++) == c) {
80 				if (c == 0)
81 					s = NULL;
82 				else
83 					s[-1] = 0;
84 				*stringp = s;
85 				return (tok);
86 			}
87 		} while (sc != 0);
88 	}
89 	/* NOTREACHED */
90 }
91