xref: /titanic_41/usr/src/lib/libbc/libc/gen/common/strtok.c (revision ae115bc77f6fcde83175c75b4206dc2e50747966)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*      Copyright (c) 1984 AT&T */
23 /*        All Rights Reserved   */
24 
25 #pragma ident	"%Z%%M%	%I%	%E% SMI"  /* from S5R2 1.2 */
26 
27 /*LINTLIBRARY*/
28 /*
29  * uses strpbrk and strspn to break string into tokens on
30  * sequentially subsequent calls.  returns NULL when no
31  * non-separator characters remain.
32  * `subsequent' calls are calls with first argument NULL.
33  */
34 
35 #define	NULL	(char*)0
36 
37 extern int strspn();
38 extern char *strpbrk();
39 
40 char *
41 strtok(string, sepset)
42 char	*string, *sepset;
43 {
44 	register char	*p, *q, *r;
45 	static char	*savept;
46 
47 	/*first or subsequent call*/
48 	p = (string == NULL)? savept: string;
49 
50 	if(p == 0)		/* return if no tokens remaining */
51 		return(NULL);
52 
53 	q = p + strspn(p, 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 		savept = 0;	/* indicate this is last token */
60 	else {
61 		*r = '\0';
62 		savept = ++r;
63 	}
64 	return(q);
65 }
66