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      1 /*	$OpenBSD: strsep.c,v 1.6 2005/08/08 08:05:37 espie Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1990, 1993
      5  *	The Regents of the University of California.  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 <string.h>
     33 #include <stdio.h>
     34 
     35 /*
     36  * Get next token from string *stringp, where tokens are possibly-empty
     37  * strings separated by characters from delim.
     38  *
     39  * Writes NULs into the string at *stringp to end tokens.
     40  * delim need not remain constant from call to call.
     41  * On return, *stringp points past the last NUL written (if there might
     42  * be further tokens), or is NULL (if there are definitely no more tokens).
     43  *
     44  * If *stringp is NULL, strsep returns NULL.
     45  */
     46 char *
     47 strsep(char **stringp, const char *delim)
     48 {
     49 	char *s;
     50 	const char *spanp;
     51 	int c, sc;
     52 	char *tok;
     53 
     54 	if ((s = *stringp) == NULL)
     55 		return (NULL);
     56 	for (tok = s;;) {
     57 		c = *s++;
     58 		spanp = delim;
     59 		do {
     60 			if ((sc = *spanp++) == c) {
     61 				if (c == 0)
     62 					s = NULL;
     63 				else
     64 					s[-1] = 0;
     65 				*stringp = s;
     66 				return (tok);
     67 			}
     68 		} while (sc != 0);
     69 	}
     70 	/* NOTREACHED */
     71 }
     72