xref: /illumos-gate/usr/src/cmd/sgs/tsort/common/errstrtok.c (revision 763f1f5f97e4c16840af2ced98915f0ed0f46616)
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 
23 /*
24  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
25  * Use is subject to license terms.
26  */
27 
28 /*	Copyright (c) 1988 AT&T	*/
29 /*	  All Rights Reserved  	*/
30 
31 /*
32  *	This is exactly strtok(3C).
33  *	It is here, with a different name, because using strtok() within
34  *	the scope of errverb() can cause the loss of a currently remembered
35  *	string(savept).
36  */
37 
38 /*
39  * uses strpbrk and strspn to break string into tokens on
40  * sequentially subsequent calls.  returns NULL when no
41  * non-separator characters remain.
42  * `subsequent' calls are calls with first argument NULL.
43  */
44 
45 #include <string.h>
46 
47 char *
48 errstrtok(char *string, char *sepset)
49 {
50 	char	*p, *q, *r;
51 	static char	*savept;
52 
53 	/* first or subsequent call */
54 	p = (string == NULL)? savept: string;
55 
56 	if (p == 0)		/* return if no tokens remaining */
57 		return (NULL);
58 
59 	q = p + strspn(p, sepset);	/* skip leading separators */
60 
61 	if (*q == '\0')		/* return if no tokens remaining */
62 		return (NULL);
63 
64 	if ((r = strpbrk(q, sepset)) == NULL)	/* move past token */
65 		savept = 0;	/* indicate this is last token */
66 	else {
67 		*r = '\0';
68 		savept = ++r;
69 	}
70 	return (q);
71 }
72