xref: /illumos-gate/usr/src/lib/libc/port/gen/strtok_r.c (revision 1a2d662a91cee3bf82f41cd47c7ae6f3825d9db2)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1988 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 #include "lint.h"
31 #include <string.h>
32 #include <stddef.h>
33 #include <sys/types.h>
34 
35 /*
36  * uses strpbrk and strspn to break string into tokens on
37  * sequentially subsequent calls.  returns NULL when no
38  * non-separator characters remain.
39  * `subsequent' calls are calls with first argument NULL.
40  */
41 char *
42 strtok_r(char *string, const char *sepset, char **lasts)
43 {
44 	char	*q, *r;
45 
46 	/* first or subsequent call */
47 	if (string == NULL)
48 		string = *lasts;
49 
50 	if (string == NULL)		/* return if no tokens remaining */
51 		return (NULL);
52 
53 	q = string + strspn(string, sepset);	/* skip leading separators */
54 
55 	if (*q == '\0')		/* return if no tokens remaining */
56 		return (NULL);
57 
58 	if ((r = strpbrk(q, sepset)) == NULL)	/* move past token */
59 		*lasts = NULL;	/* indicate this is last token */
60 	else {
61 		*r = '\0';
62 		*lasts = r + 1;
63 	}
64 	return (q);
65 }
66