xref: /titanic_51/usr/src/boot/lib/libc/string/strsep.c (revision 4a5d661a82b942b6538acd26209d959ce98b593a)
1*4a5d661aSToomas Soome /*-
2*4a5d661aSToomas Soome  * Copyright (c) 1990, 1993
3*4a5d661aSToomas Soome  *	The Regents of the University of California.  All rights reserved.
4*4a5d661aSToomas Soome  *
5*4a5d661aSToomas Soome  * Redistribution and use in source and binary forms, with or without
6*4a5d661aSToomas Soome  * modification, are permitted provided that the following conditions
7*4a5d661aSToomas Soome  * are met:
8*4a5d661aSToomas Soome  * 1. Redistributions of source code must retain the above copyright
9*4a5d661aSToomas Soome  *    notice, this list of conditions and the following disclaimer.
10*4a5d661aSToomas Soome  * 2. Redistributions in binary form must reproduce the above copyright
11*4a5d661aSToomas Soome  *    notice, this list of conditions and the following disclaimer in the
12*4a5d661aSToomas Soome  *    documentation and/or other materials provided with the distribution.
13*4a5d661aSToomas Soome  * 3. Neither the name of the University nor the names of its contributors
14*4a5d661aSToomas Soome  *    may be used to endorse or promote products derived from this software
15*4a5d661aSToomas Soome  *    without specific prior written permission.
16*4a5d661aSToomas Soome  *
17*4a5d661aSToomas Soome  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18*4a5d661aSToomas Soome  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19*4a5d661aSToomas Soome  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20*4a5d661aSToomas Soome  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21*4a5d661aSToomas Soome  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22*4a5d661aSToomas Soome  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23*4a5d661aSToomas Soome  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24*4a5d661aSToomas Soome  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25*4a5d661aSToomas Soome  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26*4a5d661aSToomas Soome  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27*4a5d661aSToomas Soome  * SUCH DAMAGE.
28*4a5d661aSToomas Soome  */
29*4a5d661aSToomas Soome 
30*4a5d661aSToomas Soome #if defined(LIBC_SCCS) && !defined(lint)
31*4a5d661aSToomas Soome static char sccsid[] = "@(#)strsep.c	8.1 (Berkeley) 6/4/93";
32*4a5d661aSToomas Soome #endif /* LIBC_SCCS and not lint */
33*4a5d661aSToomas Soome #include <sys/cdefs.h>
34*4a5d661aSToomas Soome __FBSDID("$FreeBSD$");
35*4a5d661aSToomas Soome 
36*4a5d661aSToomas Soome #include <string.h>
37*4a5d661aSToomas Soome #include <stdio.h>
38*4a5d661aSToomas Soome 
39*4a5d661aSToomas Soome /*
40*4a5d661aSToomas Soome  * Get next token from string *stringp, where tokens are possibly-empty
41*4a5d661aSToomas Soome  * strings separated by characters from delim.
42*4a5d661aSToomas Soome  *
43*4a5d661aSToomas Soome  * Writes NULs into the string at *stringp to end tokens.
44*4a5d661aSToomas Soome  * delim need not remain constant from call to call.
45*4a5d661aSToomas Soome  * On return, *stringp points past the last NUL written (if there might
46*4a5d661aSToomas Soome  * be further tokens), or is NULL (if there are definitely no more tokens).
47*4a5d661aSToomas Soome  *
48*4a5d661aSToomas Soome  * If *stringp is NULL, strsep returns NULL.
49*4a5d661aSToomas Soome  */
50*4a5d661aSToomas Soome char *
51*4a5d661aSToomas Soome strsep(char **stringp, const char *delim)
52*4a5d661aSToomas Soome {
53*4a5d661aSToomas Soome 	char *s;
54*4a5d661aSToomas Soome 	const char *spanp;
55*4a5d661aSToomas Soome 	int c, sc;
56*4a5d661aSToomas Soome 	char *tok;
57*4a5d661aSToomas Soome 
58*4a5d661aSToomas Soome 	if ((s = *stringp) == NULL)
59*4a5d661aSToomas Soome 		return (NULL);
60*4a5d661aSToomas Soome 	for (tok = s;;) {
61*4a5d661aSToomas Soome 		c = *s++;
62*4a5d661aSToomas Soome 		spanp = delim;
63*4a5d661aSToomas Soome 		do {
64*4a5d661aSToomas Soome 			if ((sc = *spanp++) == c) {
65*4a5d661aSToomas Soome 				if (c == 0)
66*4a5d661aSToomas Soome 					s = NULL;
67*4a5d661aSToomas Soome 				else
68*4a5d661aSToomas Soome 					s[-1] = 0;
69*4a5d661aSToomas Soome 				*stringp = s;
70*4a5d661aSToomas Soome 				return (tok);
71*4a5d661aSToomas Soome 			}
72*4a5d661aSToomas Soome 		} while (sc != 0);
73*4a5d661aSToomas Soome 	}
74*4a5d661aSToomas Soome 	/* NOTREACHED */
75*4a5d661aSToomas Soome }
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