xref: /xnu-11215.81.4/libsyscall/wrappers/string/strsep.c (revision d4514f0bc1d3f944c22d92e68b646ac3fb40d452)
1*d4514f0bSApple OSS Distributions /*-
2*d4514f0bSApple OSS Distributions  * Copyright (c) 1990, 1993
3*d4514f0bSApple OSS Distributions  *	The Regents of the University of California.  All rights reserved.
4*d4514f0bSApple OSS Distributions  *
5*d4514f0bSApple OSS Distributions  * Redistribution and use in source and binary forms, with or without
6*d4514f0bSApple OSS Distributions  * modification, are permitted provided that the following conditions
7*d4514f0bSApple OSS Distributions  * are met:
8*d4514f0bSApple OSS Distributions  * 1. Redistributions of source code must retain the above copyright
9*d4514f0bSApple OSS Distributions  *    notice, this list of conditions and the following disclaimer.
10*d4514f0bSApple OSS Distributions  * 2. Redistributions in binary form must reproduce the above copyright
11*d4514f0bSApple OSS Distributions  *    notice, this list of conditions and the following disclaimer in the
12*d4514f0bSApple OSS Distributions  *    documentation and/or other materials provided with the distribution.
13*d4514f0bSApple OSS Distributions  * 4. Neither the name of the University nor the names of its contributors
14*d4514f0bSApple OSS Distributions  *    may be used to endorse or promote products derived from this software
15*d4514f0bSApple OSS Distributions  *    without specific prior written permission.
16*d4514f0bSApple OSS Distributions  *
17*d4514f0bSApple OSS Distributions  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18*d4514f0bSApple OSS Distributions  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19*d4514f0bSApple OSS Distributions  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20*d4514f0bSApple OSS Distributions  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21*d4514f0bSApple OSS Distributions  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22*d4514f0bSApple OSS Distributions  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23*d4514f0bSApple OSS Distributions  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24*d4514f0bSApple OSS Distributions  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25*d4514f0bSApple OSS Distributions  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26*d4514f0bSApple OSS Distributions  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27*d4514f0bSApple OSS Distributions  * SUCH DAMAGE.
28*d4514f0bSApple OSS Distributions  */
29*d4514f0bSApple OSS Distributions 
30*d4514f0bSApple OSS Distributions #include "string.h"
31*d4514f0bSApple OSS Distributions 
32*d4514f0bSApple OSS Distributions /*
33*d4514f0bSApple OSS Distributions  * Get next token from string *stringp, where tokens are possibly-empty
34*d4514f0bSApple OSS Distributions  * strings separated by characters from delim.
35*d4514f0bSApple OSS Distributions  *
36*d4514f0bSApple OSS Distributions  * Writes NULs into the string at *stringp to end tokens.
37*d4514f0bSApple OSS Distributions  * delim need not remain constant from call to call.
38*d4514f0bSApple OSS Distributions  * On return, *stringp points past the last NUL written (if there might
39*d4514f0bSApple OSS Distributions  * be further tokens), or is NULL (if there are definitely no more tokens).
40*d4514f0bSApple OSS Distributions  *
41*d4514f0bSApple OSS Distributions  * If *stringp is NULL, strsep returns NULL.
42*d4514f0bSApple OSS Distributions  */
43*d4514f0bSApple OSS Distributions __attribute__((visibility("hidden")))
44*d4514f0bSApple OSS Distributions char *
strsep(char ** stringp,const char * delim)45*d4514f0bSApple OSS Distributions strsep(char **stringp, const char *delim)
46*d4514f0bSApple OSS Distributions {
47*d4514f0bSApple OSS Distributions 	char *s;
48*d4514f0bSApple OSS Distributions 	const char *spanp;
49*d4514f0bSApple OSS Distributions 	int c, sc;
50*d4514f0bSApple OSS Distributions 	char *tok;
51*d4514f0bSApple OSS Distributions 
52*d4514f0bSApple OSS Distributions 	if ((s = *stringp) == NULL) {
53*d4514f0bSApple OSS Distributions 		return NULL;
54*d4514f0bSApple OSS Distributions 	}
55*d4514f0bSApple OSS Distributions 	for (tok = s;;) {
56*d4514f0bSApple OSS Distributions 		c = *s++;
57*d4514f0bSApple OSS Distributions 		spanp = delim;
58*d4514f0bSApple OSS Distributions 		do {
59*d4514f0bSApple OSS Distributions 			if ((sc = *spanp++) == c) {
60*d4514f0bSApple OSS Distributions 				if (c == 0) {
61*d4514f0bSApple OSS Distributions 					s = NULL;
62*d4514f0bSApple OSS Distributions 				} else {
63*d4514f0bSApple OSS Distributions 					s[-1] = 0;
64*d4514f0bSApple OSS Distributions 				}
65*d4514f0bSApple OSS Distributions 				*stringp = s;
66*d4514f0bSApple OSS Distributions 				return tok;
67*d4514f0bSApple OSS Distributions 			}
68*d4514f0bSApple OSS Distributions 		} while (sc != 0);
69*d4514f0bSApple OSS Distributions 	}
70*d4514f0bSApple OSS Distributions 	/* NOTREACHED */
71*d4514f0bSApple OSS Distributions }
72