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strtok_r.c revision 1.6 
      1 /*	$NetBSD: strtok_r.c,v 1.6 1999/09/16 11:45:43 lukem 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. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #if defined(LIBC_SCCS) && !defined(lint)
     38 #if 0
     39 static char *sccsid = "@(#)strtok.c	5.8 (Berkeley) 2/24/91";
     40 #else
     41 __RCSID("$NetBSD: strtok_r.c,v 1.6 1999/09/16 11:45:43 lukem Exp $");
     42 #endif
     43 #endif /* LIBC_SCCS and not lint */
     44 
     45 #include "namespace.h"
     46 
     47 #include <assert.h>
     48 #include <string.h>
     49 
     50 #ifdef __weak_alias
     51 __weak_alias(strtok_r,_strtok_r);
     52 #endif
     53 
     54 char *
     55 strtok_r(s, delim, lasts)
     56 	char *s;
     57 	const char *delim;
     58 	char **lasts;
     59 {
     60 	const char *spanp;
     61 	int c, sc;
     62 	char *tok;
     63 
     64 	/* s may be NULL */
     65 	_DIAGASSERT(delim != NULL);
     66 	_DIAGASSERT(lasts != NULL);
     67 #ifdef _DIAGNOSTIC
     68 	if (delim == NULL || lasts == NULL)
     69 		return (NULL);
     70 #endif
     71 
     72 	if (s == NULL && (s = *lasts) == NULL)
     73 		return (NULL);
     74 
     75 	/*
     76 	 * Skip (span) leading delimiters (s += strspn(s, delim), sort of).
     77 	 */
     78 cont:
     79 	c = *s++;
     80 	for (spanp = delim; (sc = *spanp++) != 0;) {
     81 		if (c == sc)
     82 			goto cont;
     83 	}
     84 
     85 	if (c == 0) {		/* no non-delimiter characters */
     86 		*lasts = NULL;
     87 		return (NULL);
     88 	}
     89 	tok = s - 1;
     90 
     91 	/*
     92 	 * Scan token (scan for delimiters: s += strcspn(s, delim), sort of).
     93 	 * Note that delim must have one NUL; we stop if we see that, too.
     94 	 */
     95 	for (;;) {
     96 		c = *s++;
     97 		spanp = delim;
     98 		do {
     99 			if ((sc = *spanp++) == c) {
    100 				if (c == 0)
    101 					s = NULL;
    102 				else
    103 					s[-1] = 0;
    104 				*lasts = s;
    105 				return (tok);
    106 			}
    107 		} while (sc != 0);
    108 	}
    109 	/* NOTREACHED */
    110 }
    111