xref: /xnu-10002.1.13/libsyscall/wrappers/string/strsep.c (revision 1031c584a5e37aff177559b9f69dbd3c8c3fd30a)
1*1031c584SApple OSS Distributions /*-
2*1031c584SApple OSS Distributions  * Copyright (c) 1990, 1993
3*1031c584SApple OSS Distributions  *	The Regents of the University of California.  All rights reserved.
4*1031c584SApple OSS Distributions  *
5*1031c584SApple OSS Distributions  * Redistribution and use in source and binary forms, with or without
6*1031c584SApple OSS Distributions  * modification, are permitted provided that the following conditions
7*1031c584SApple OSS Distributions  * are met:
8*1031c584SApple OSS Distributions  * 1. Redistributions of source code must retain the above copyright
9*1031c584SApple OSS Distributions  *    notice, this list of conditions and the following disclaimer.
10*1031c584SApple OSS Distributions  * 2. Redistributions in binary form must reproduce the above copyright
11*1031c584SApple OSS Distributions  *    notice, this list of conditions and the following disclaimer in the
12*1031c584SApple OSS Distributions  *    documentation and/or other materials provided with the distribution.
13*1031c584SApple OSS Distributions  * 4. Neither the name of the University nor the names of its contributors
14*1031c584SApple OSS Distributions  *    may be used to endorse or promote products derived from this software
15*1031c584SApple OSS Distributions  *    without specific prior written permission.
16*1031c584SApple OSS Distributions  *
17*1031c584SApple OSS Distributions  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18*1031c584SApple OSS Distributions  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19*1031c584SApple OSS Distributions  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20*1031c584SApple OSS Distributions  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21*1031c584SApple OSS Distributions  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22*1031c584SApple OSS Distributions  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23*1031c584SApple OSS Distributions  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24*1031c584SApple OSS Distributions  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25*1031c584SApple OSS Distributions  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26*1031c584SApple OSS Distributions  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27*1031c584SApple OSS Distributions  * SUCH DAMAGE.
28*1031c584SApple OSS Distributions  */
29*1031c584SApple OSS Distributions 
30*1031c584SApple OSS Distributions #include "string.h"
31*1031c584SApple OSS Distributions 
32*1031c584SApple OSS Distributions /*
33*1031c584SApple OSS Distributions  * Get next token from string *stringp, where tokens are possibly-empty
34*1031c584SApple OSS Distributions  * strings separated by characters from delim.
35*1031c584SApple OSS Distributions  *
36*1031c584SApple OSS Distributions  * Writes NULs into the string at *stringp to end tokens.
37*1031c584SApple OSS Distributions  * delim need not remain constant from call to call.
38*1031c584SApple OSS Distributions  * On return, *stringp points past the last NUL written (if there might
39*1031c584SApple OSS Distributions  * be further tokens), or is NULL (if there are definitely no more tokens).
40*1031c584SApple OSS Distributions  *
41*1031c584SApple OSS Distributions  * If *stringp is NULL, strsep returns NULL.
42*1031c584SApple OSS Distributions  */
43*1031c584SApple OSS Distributions __attribute__((visibility("hidden")))
44*1031c584SApple OSS Distributions char *
strsep(char ** stringp,const char * delim)45*1031c584SApple OSS Distributions strsep(char **stringp, const char *delim)
46*1031c584SApple OSS Distributions {
47*1031c584SApple OSS Distributions 	char *s;
48*1031c584SApple OSS Distributions 	const char *spanp;
49*1031c584SApple OSS Distributions 	int c, sc;
50*1031c584SApple OSS Distributions 	char *tok;
51*1031c584SApple OSS Distributions 
52*1031c584SApple OSS Distributions 	if ((s = *stringp) == NULL) {
53*1031c584SApple OSS Distributions 		return NULL;
54*1031c584SApple OSS Distributions 	}
55*1031c584SApple OSS Distributions 	for (tok = s;;) {
56*1031c584SApple OSS Distributions 		c = *s++;
57*1031c584SApple OSS Distributions 		spanp = delim;
58*1031c584SApple OSS Distributions 		do {
59*1031c584SApple OSS Distributions 			if ((sc = *spanp++) == c) {
60*1031c584SApple OSS Distributions 				if (c == 0) {
61*1031c584SApple OSS Distributions 					s = NULL;
62*1031c584SApple OSS Distributions 				} else {
63*1031c584SApple OSS Distributions 					s[-1] = 0;
64*1031c584SApple OSS Distributions 				}
65*1031c584SApple OSS Distributions 				*stringp = s;
66*1031c584SApple OSS Distributions 				return tok;
67*1031c584SApple OSS Distributions 			}
68*1031c584SApple OSS Distributions 		} while (sc != 0);
69*1031c584SApple OSS Distributions 	}
70*1031c584SApple OSS Distributions 	/* NOTREACHED */
71*1031c584SApple OSS Distributions }
72