xref: /illumos-gate/usr/src/cmd/sgs/tsort/common/errstrtok.c (revision 2a8bcb4e)

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*	Copyright (c) 1988 AT&T	*/
/*	  All Rights Reserved  	*/

/*
 *	This is exactly strtok(3C).
 *	It is here, with a different name, because using strtok() within
 *	the scope of errverb() can cause the loss of a currently remembered
 *	string(savept).
 */

/*
 * uses strpbrk and strspn to break string into tokens on
 * sequentially subsequent calls.  returns NULL when no
 * non-separator characters remain.
 * `subsequent' calls are calls with first argument NULL.
 */

#include <string.h>

char *
errstrtok(char *string, char *sepset)
{
	char	*p, *q, *r;
	static char	*savept;

	/* first or subsequent call */
	p = (string == NULL)? savept: string;

	if (p == 0)		/* return if no tokens remaining */
		return (NULL);

	q = p + strspn(p, sepset);	/* skip leading separators */

	if (*q == '\0')		/* return if no tokens remaining */
		return (NULL);

	if ((r = strpbrk(q, sepset)) == NULL)	/* move past token */
		savept = 0;	/* indicate this is last token */
	else {
		*r = '\0';
		savept = ++r;
	}
	return (q);
}