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strtok_r.c revision 1.1 
      1 /*
      2  * Copyright (c) 1988 Regents of the University of California.
      3  * All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  * 3. All advertising materials mentioning features or use of this software
     14  *    must display the following acknowledgement:
     15  *	This product includes software developed by the University of
     16  *	California, Berkeley and its contributors.
     17  * 4. Neither the name of the University nor the names of its contributors
     18  *    may be used to endorse or promote products derived from this software
     19  *    without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     31  * SUCH DAMAGE.
     32  */
     33 
     34 #if defined(LIBC_SCCS) && !defined(lint)
     35 /*static char *sccsid = "from: @(#)strtok.c	5.8 (Berkeley) 2/24/91";*/
     36 static char *rcsid = "$Id: strtok_r.c,v 1.1 1996/11/12 02:03:14 jtc Exp $";
     37 #endif /* LIBC_SCCS and not lint */
     38 
     39 #include <string.h>
     40 
     41 char *
     42 strtok_r(s, delim, lasts)
     43 	register char *s;
     44 	register const char *delim;
     45 	register char **lasts;
     46 {
     47 	register char *spanp;
     48 	register int c, sc;
     49 	char *tok;
     50 
     51 	if (s == NULL && (s = *lasts) == NULL)
     52 		return (NULL);
     53 
     54 	/*
     55 	 * Skip (span) leading delimiters (s += strspn(s, delim), sort of).
     56 	 */
     57 cont:
     58 	c = *s++;
     59 	for (spanp = (char *)delim; (sc = *spanp++) != 0;) {
     60 		if (c == sc)
     61 			goto cont;
     62 	}
     63 
     64 	if (c == 0) {		/* no non-delimiter characters */
     65 		*lasts = NULL;
     66 		return (NULL);
     67 	}
     68 	tok = s - 1;
     69 
     70 	/*
     71 	 * Scan token (scan for delimiters: s += strcspn(s, delim), sort of).
     72 	 * Note that delim must have one NUL; we stop if we see that, too.
     73 	 */
     74 	for (;;) {
     75 		c = *s++;
     76 		spanp = (char *)delim;
     77 		do {
     78 			if ((sc = *spanp++) == c) {
     79 				if (c == 0)
     80 					s = NULL;
     81 				else
     82 					s[-1] = 0;
     83 				*lasts = s;
     84 				return (tok);
     85 			}
     86 		} while (sc != 0);
     87 	}
     88 	/* NOTREACHED */
     89 }
     90