strsep.c revision 77117 
1/*-
2 * Copyright (c) 1990, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include <sys/cdefs.h>
35#include <string.h>
36#include <stdio.h>
37
38#if defined(LIBC_SCCS) && !defined(lint)
39static char sccsid[] = "@(#)strsep.c	8.1 (Berkeley) 6/4/93";
40#endif /* LIBC_SCCS and not lint */
41#ifndef lint
42static const char rcsid[] =
43  "$FreeBSD: head/lib/libc/string/strsep.c 77117 2001-05-24 08:47:42Z obrien $";
44#endif
45
46/*
47 * Get next token from string *stringp, where tokens are possibly-empty
48 * strings separated by characters from delim.
49 *
50 * Writes NULs into the string at *stringp to end tokens.
51 * delim need not remain constant from call to call.
52 * On return, *stringp points past the last NUL written (if there might
53 * be further tokens), or is NULL (if there are definitely no more tokens).
54 *
55 * If *stringp is NULL, strsep returns NULL.
56 */
57char *
58strsep(stringp, delim)
59	register char **stringp;
60	register const char *delim;
61{
62	register char *s;
63	register const char *spanp;
64	register int c, sc;
65	char *tok;
66
67	if ((s = *stringp) == NULL)
68		return (NULL);
69	for (tok = s;;) {
70		c = *s++;
71		spanp = delim;
72		do {
73			if ((sc = *spanp++) == c) {
74				if (c == 0)
75					s = NULL;
76				else
77					s[-1] = 0;
78				*stringp = s;
79				return (tok);
80			}
81		} while (sc != 0);
82	}
83	/* NOTREACHED */
84}
85