xref: /xnu-8020.121.3/bsd/libkern/strsep.c (revision fdd8201d7b966f0c3ea610489d29bd841d358941)
1*fdd8201dSApple OSS Distributions /*
2*fdd8201dSApple OSS Distributions  * Copyright (c) 2016 Apple Inc. All rights reserved.
3*fdd8201dSApple OSS Distributions  *
4*fdd8201dSApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5*fdd8201dSApple OSS Distributions  *
6*fdd8201dSApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
7*fdd8201dSApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
8*fdd8201dSApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
9*fdd8201dSApple OSS Distributions  * compliance with the License. The rights granted to you under the License
10*fdd8201dSApple OSS Distributions  * may not be used to create, or enable the creation or redistribution of,
11*fdd8201dSApple OSS Distributions  * unlawful or unlicensed copies of an Apple operating system, or to
12*fdd8201dSApple OSS Distributions  * circumvent, violate, or enable the circumvention or violation of, any
13*fdd8201dSApple OSS Distributions  * terms of an Apple operating system software license agreement.
14*fdd8201dSApple OSS Distributions  *
15*fdd8201dSApple OSS Distributions  * Please obtain a copy of the License at
16*fdd8201dSApple OSS Distributions  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17*fdd8201dSApple OSS Distributions  *
18*fdd8201dSApple OSS Distributions  * The Original Code and all software distributed under the License are
19*fdd8201dSApple OSS Distributions  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20*fdd8201dSApple OSS Distributions  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21*fdd8201dSApple OSS Distributions  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22*fdd8201dSApple OSS Distributions  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23*fdd8201dSApple OSS Distributions  * Please see the License for the specific language governing rights and
24*fdd8201dSApple OSS Distributions  * limitations under the License.
25*fdd8201dSApple OSS Distributions  *
26*fdd8201dSApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27*fdd8201dSApple OSS Distributions  */
28*fdd8201dSApple OSS Distributions 
29*fdd8201dSApple OSS Distributions /*-
30*fdd8201dSApple OSS Distributions  * Copyright (c) 1990, 1993
31*fdd8201dSApple OSS Distributions  *	The Regents of the University of California.  All rights reserved.
32*fdd8201dSApple OSS Distributions  *
33*fdd8201dSApple OSS Distributions  * Redistribution and use in source and binary forms, with or without
34*fdd8201dSApple OSS Distributions  * modification, are permitted provided that the following conditions
35*fdd8201dSApple OSS Distributions  * are met:
36*fdd8201dSApple OSS Distributions  * 1. Redistributions of source code must retain the above copyright
37*fdd8201dSApple OSS Distributions  *    notice, this list of conditions and the following disclaimer.
38*fdd8201dSApple OSS Distributions  * 2. Redistributions in binary form must reproduce the above copyright
39*fdd8201dSApple OSS Distributions  *    notice, this list of conditions and the following disclaimer in the
40*fdd8201dSApple OSS Distributions  *    documentation and/or other materials provided with the distribution.
41*fdd8201dSApple OSS Distributions  * 4. Neither the name of the University nor the names of its contributors
42*fdd8201dSApple OSS Distributions  *    may be used to endorse or promote products derived from this software
43*fdd8201dSApple OSS Distributions  *    without specific prior written permission.
44*fdd8201dSApple OSS Distributions  *
45*fdd8201dSApple OSS Distributions  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
46*fdd8201dSApple OSS Distributions  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
47*fdd8201dSApple OSS Distributions  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
48*fdd8201dSApple OSS Distributions  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
49*fdd8201dSApple OSS Distributions  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
50*fdd8201dSApple OSS Distributions  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
51*fdd8201dSApple OSS Distributions  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
52*fdd8201dSApple OSS Distributions  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
53*fdd8201dSApple OSS Distributions  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
54*fdd8201dSApple OSS Distributions  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
55*fdd8201dSApple OSS Distributions  * SUCH DAMAGE.
56*fdd8201dSApple OSS Distributions  */
57*fdd8201dSApple OSS Distributions 
58*fdd8201dSApple OSS Distributions #if defined(LIBC_SCCS) && !defined(lint)
59*fdd8201dSApple OSS Distributions static char sccsid[] = "@(#)strsep.c	8.1 (Berkeley) 6/4/93";
60*fdd8201dSApple OSS Distributions #endif /* LIBC_SCCS and not lint */
61*fdd8201dSApple OSS Distributions #include <sys/cdefs.h>
62*fdd8201dSApple OSS Distributions /* __FBSDID("$FreeBSD: src/sys/libkern/strsep.c,v 1.7 2004/04/07 20:46:10 imp Exp $"); */
63*fdd8201dSApple OSS Distributions 
64*fdd8201dSApple OSS Distributions #include <sys/param.h>
65*fdd8201dSApple OSS Distributions #include <libkern/libkern.h>
66*fdd8201dSApple OSS Distributions 
67*fdd8201dSApple OSS Distributions /*
68*fdd8201dSApple OSS Distributions  * Get next token from string *stringp, where tokens are possibly-empty
69*fdd8201dSApple OSS Distributions  * strings separated by characters from delim.
70*fdd8201dSApple OSS Distributions  *
71*fdd8201dSApple OSS Distributions  * Writes NULs into the string at *stringp to end tokens.
72*fdd8201dSApple OSS Distributions  * delim need not remain constant from call to call.
73*fdd8201dSApple OSS Distributions  * On return, *stringp points past the last NUL written (if there might
74*fdd8201dSApple OSS Distributions  * be further tokens), or is NULL (if there are definitely no more tokens).
75*fdd8201dSApple OSS Distributions  *
76*fdd8201dSApple OSS Distributions  * If *stringp is NULL, strsep returns NULL.
77*fdd8201dSApple OSS Distributions  */
78*fdd8201dSApple OSS Distributions char *
strsep(char ** stringp,const char * delim)79*fdd8201dSApple OSS Distributions strsep(char **stringp, const char *delim)
80*fdd8201dSApple OSS Distributions {
81*fdd8201dSApple OSS Distributions 	char *s;
82*fdd8201dSApple OSS Distributions 	const char *spanp;
83*fdd8201dSApple OSS Distributions 	int c, sc;
84*fdd8201dSApple OSS Distributions 	char *tok;
85*fdd8201dSApple OSS Distributions 
86*fdd8201dSApple OSS Distributions 	if ((s = *stringp) == NULL) {
87*fdd8201dSApple OSS Distributions 		return NULL;
88*fdd8201dSApple OSS Distributions 	}
89*fdd8201dSApple OSS Distributions 	for (tok = s;;) {
90*fdd8201dSApple OSS Distributions 		c = *s++;
91*fdd8201dSApple OSS Distributions 		spanp = delim;
92*fdd8201dSApple OSS Distributions 		do {
93*fdd8201dSApple OSS Distributions 			if ((sc = *spanp++) == c) {
94*fdd8201dSApple OSS Distributions 				if (c == 0) {
95*fdd8201dSApple OSS Distributions 					s = NULL;
96*fdd8201dSApple OSS Distributions 				} else {
97*fdd8201dSApple OSS Distributions 					s[-1] = 0;
98*fdd8201dSApple OSS Distributions 				}
99*fdd8201dSApple OSS Distributions 				*stringp = s;
100*fdd8201dSApple OSS Distributions 				return tok;
101*fdd8201dSApple OSS Distributions 			}
102*fdd8201dSApple OSS Distributions 		} while (sc != 0);
103*fdd8201dSApple OSS Distributions 	}
104*fdd8201dSApple OSS Distributions 	/* NOTREACHED */
105*fdd8201dSApple OSS Distributions }
106