1 /* $NetBSD: stresep.c,v 1.4 2017/08/23 10:27:41 christos 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 1.4 2017/08/23 10:27:41 christos 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 size_t l;
70 char *tok;
71
72 _DIAGASSERT(stringp != NULL);
73 _DIAGASSERT(delim != NULL);
74
75 if ((s = *stringp) == NULL)
76 return NULL;
77 l = strlen(s) + 1;
78 for (tok = s;;) {
79 c = *s++;
80 l--;
81 while (esc != '\0' && c == esc) {
82 memmove(s - 1, s, l);
83 c = *s++;
84 l--;
85 }
86 spanp = delim;
87 do {
88 if ((sc = *spanp++) == c) {
89 if (c == '\0')
90 s = NULL;
91 else
92 s[-1] = '\0';
93 *stringp = s;
94 return tok;
95 }
96 } while (sc != '\0');
97 }
98 }
99