xref: /xnu-10002.81.5/libsyscall/wrappers/string/strsep.c (revision 5e3eaea39dcf651e66cb99ba7d70e32cc4a99587)
1*5e3eaea3SApple OSS Distributions /*-
2*5e3eaea3SApple OSS Distributions  * Copyright (c) 1990, 1993
3*5e3eaea3SApple OSS Distributions  *	The Regents of the University of California.  All rights reserved.
4*5e3eaea3SApple OSS Distributions  *
5*5e3eaea3SApple OSS Distributions  * Redistribution and use in source and binary forms, with or without
6*5e3eaea3SApple OSS Distributions  * modification, are permitted provided that the following conditions
7*5e3eaea3SApple OSS Distributions  * are met:
8*5e3eaea3SApple OSS Distributions  * 1. Redistributions of source code must retain the above copyright
9*5e3eaea3SApple OSS Distributions  *    notice, this list of conditions and the following disclaimer.
10*5e3eaea3SApple OSS Distributions  * 2. Redistributions in binary form must reproduce the above copyright
11*5e3eaea3SApple OSS Distributions  *    notice, this list of conditions and the following disclaimer in the
12*5e3eaea3SApple OSS Distributions  *    documentation and/or other materials provided with the distribution.
13*5e3eaea3SApple OSS Distributions  * 4. Neither the name of the University nor the names of its contributors
14*5e3eaea3SApple OSS Distributions  *    may be used to endorse or promote products derived from this software
15*5e3eaea3SApple OSS Distributions  *    without specific prior written permission.
16*5e3eaea3SApple OSS Distributions  *
17*5e3eaea3SApple OSS Distributions  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18*5e3eaea3SApple OSS Distributions  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19*5e3eaea3SApple OSS Distributions  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20*5e3eaea3SApple OSS Distributions  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21*5e3eaea3SApple OSS Distributions  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22*5e3eaea3SApple OSS Distributions  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23*5e3eaea3SApple OSS Distributions  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24*5e3eaea3SApple OSS Distributions  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25*5e3eaea3SApple OSS Distributions  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26*5e3eaea3SApple OSS Distributions  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27*5e3eaea3SApple OSS Distributions  * SUCH DAMAGE.
28*5e3eaea3SApple OSS Distributions  */
29*5e3eaea3SApple OSS Distributions 
30*5e3eaea3SApple OSS Distributions #include "string.h"
31*5e3eaea3SApple OSS Distributions 
32*5e3eaea3SApple OSS Distributions /*
33*5e3eaea3SApple OSS Distributions  * Get next token from string *stringp, where tokens are possibly-empty
34*5e3eaea3SApple OSS Distributions  * strings separated by characters from delim.
35*5e3eaea3SApple OSS Distributions  *
36*5e3eaea3SApple OSS Distributions  * Writes NULs into the string at *stringp to end tokens.
37*5e3eaea3SApple OSS Distributions  * delim need not remain constant from call to call.
38*5e3eaea3SApple OSS Distributions  * On return, *stringp points past the last NUL written (if there might
39*5e3eaea3SApple OSS Distributions  * be further tokens), or is NULL (if there are definitely no more tokens).
40*5e3eaea3SApple OSS Distributions  *
41*5e3eaea3SApple OSS Distributions  * If *stringp is NULL, strsep returns NULL.
42*5e3eaea3SApple OSS Distributions  */
43*5e3eaea3SApple OSS Distributions __attribute__((visibility("hidden")))
44*5e3eaea3SApple OSS Distributions char *
strsep(char ** stringp,const char * delim)45*5e3eaea3SApple OSS Distributions strsep(char **stringp, const char *delim)
46*5e3eaea3SApple OSS Distributions {
47*5e3eaea3SApple OSS Distributions 	char *s;
48*5e3eaea3SApple OSS Distributions 	const char *spanp;
49*5e3eaea3SApple OSS Distributions 	int c, sc;
50*5e3eaea3SApple OSS Distributions 	char *tok;
51*5e3eaea3SApple OSS Distributions 
52*5e3eaea3SApple OSS Distributions 	if ((s = *stringp) == NULL) {
53*5e3eaea3SApple OSS Distributions 		return NULL;
54*5e3eaea3SApple OSS Distributions 	}
55*5e3eaea3SApple OSS Distributions 	for (tok = s;;) {
56*5e3eaea3SApple OSS Distributions 		c = *s++;
57*5e3eaea3SApple OSS Distributions 		spanp = delim;
58*5e3eaea3SApple OSS Distributions 		do {
59*5e3eaea3SApple OSS Distributions 			if ((sc = *spanp++) == c) {
60*5e3eaea3SApple OSS Distributions 				if (c == 0) {
61*5e3eaea3SApple OSS Distributions 					s = NULL;
62*5e3eaea3SApple OSS Distributions 				} else {
63*5e3eaea3SApple OSS Distributions 					s[-1] = 0;
64*5e3eaea3SApple OSS Distributions 				}
65*5e3eaea3SApple OSS Distributions 				*stringp = s;
66*5e3eaea3SApple OSS Distributions 				return tok;
67*5e3eaea3SApple OSS Distributions 			}
68*5e3eaea3SApple OSS Distributions 		} while (sc != 0);
69*5e3eaea3SApple OSS Distributions 	}
70*5e3eaea3SApple OSS Distributions 	/* NOTREACHED */
71*5e3eaea3SApple OSS Distributions }
72