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strtok_r.c revision 1.9 
      1 /*	$NetBSD: strtok_r.c,v 1.9 2003/08/07 16:43:53 agc Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1988 Regents of the University of California.
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 #if defined(LIBC_SCCS) && !defined(lint)
     34 #if 0
     35 static char *sccsid = "@(#)strtok.c	5.8 (Berkeley) 2/24/91";
     36 #else
     37 __RCSID("$NetBSD: strtok_r.c,v 1.9 2003/08/07 16:43:53 agc Exp $");
     38 #endif
     39 #endif /* LIBC_SCCS and not lint */
     40 
     41 #include "namespace.h"
     42 
     43 #include <assert.h>
     44 #include <string.h>
     45 
     46 #ifdef __weak_alias
     47 __weak_alias(strtok_r,_strtok_r)
     48 #endif
     49 
     50 char *
     51 strtok_r(s, delim, lasts)
     52 	char *s;
     53 	const char *delim;
     54 	char **lasts;
     55 {
     56 	const char *spanp;
     57 	int c, sc;
     58 	char *tok;
     59 
     60 	/* s may be NULL */
     61 	_DIAGASSERT(delim != NULL);
     62 	_DIAGASSERT(lasts != NULL);
     63 
     64 	if (s == NULL && (s = *lasts) == NULL)
     65 		return (NULL);
     66 
     67 	/*
     68 	 * Skip (span) leading delimiters (s += strspn(s, delim), sort of).
     69 	 */
     70 cont:
     71 	c = *s++;
     72 	for (spanp = delim; (sc = *spanp++) != 0;) {
     73 		if (c == sc)
     74 			goto cont;
     75 	}
     76 
     77 	if (c == 0) {		/* no non-delimiter characters */
     78 		*lasts = NULL;
     79 		return (NULL);
     80 	}
     81 	tok = s - 1;
     82 
     83 	/*
     84 	 * Scan token (scan for delimiters: s += strcspn(s, delim), sort of).
     85 	 * Note that delim must have one NUL; we stop if we see that, too.
     86 	 */
     87 	for (;;) {
     88 		c = *s++;
     89 		spanp = delim;
     90 		do {
     91 			if ((sc = *spanp++) == c) {
     92 				if (c == 0)
     93 					s = NULL;
     94 				else
     95 					s[-1] = 0;
     96 				*lasts = s;
     97 				return (tok);
     98 			}
     99 		} while (sc != 0);
    100 	}
    101 	/* NOTREACHED */
    102 }
    103