xref: /illumos-gate/usr/src/cmd/sgs/tsort/common/errstrtok.c (revision 71815ce76261aa773c97600750fdce92334d1990)
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 #pragma ident	"%Z%%M%	%I%	%E% SMI"
33 
34 /*
35  *	This is exactly strtok(3C).
36  *	It is here, with a different name, because using strtok() within
37  *	the scope of errverb() can cause the loss of a currently remembered
38  *	string(savept).
39  */
40 
41 /*
42  * uses strpbrk and strspn to break string into tokens on
43  * sequentially subsequent calls.  returns NULL when no
44  * non-separator characters remain.
45  * `subsequent' calls are calls with first argument NULL.
46  */
47 
48 #include <string.h>
49 
50 char *
51 errstrtok(char *string, char *sepset)
52 {
53 	char	*p, *q, *r;
54 	static char	*savept;
55 
56 	/* first or subsequent call */
57 	p = (string == NULL)? savept: string;
58 
59 	if (p == 0)		/* return if no tokens remaining */
60 		return (NULL);
61 
62 	q = p + strspn(p, sepset);	/* skip leading separators */
63 
64 	if (*q == '\0')		/* return if no tokens remaining */
65 		return (NULL);
66 
67 	if ((r = strpbrk(q, sepset)) == NULL)	/* move past token */
68 		savept = 0;	/* indicate this is last token */
69 	else {
70 		*r = '\0';
71 		savept = ++r;
72 	}
73 	return (q);
74 }
75