stresep.c revision 1.2 
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
35static 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
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 */
63char *
64stresep(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