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wcstok.c revision 1.3 
      1 /* $NetBSD: wcstok.c,v 1.3 2003/07/10 08:50:48 tshiozak Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 1998 Softweyr LLC.  All rights reserved.
      5  *
      6  * strtok_r, from Berkeley strtok
      7  * Oct 13, 1998 by Wes Peters <wes (at) softweyr.com>
      8  *
      9  * Copyright (c) 1988, 1993
     10  *	The Regents of the University of California.  All rights reserved.
     11  *
     12  * Redistribution and use in source and binary forms, with or without
     13  * modification, are permitted provided that the following conditions
     14  * are met:
     15  * 1. Redistributions of source code must retain the above copyright
     16  *    notices, this list of conditions and the following disclaimer.
     17  * 2. Redistributions in binary form must reproduce the above copyright
     18  *    notices, this list of conditions and the following disclaimer in the
     19  *    documentation and/or other materials provided with the distribution.
     20  * 3. All advertising materials mentioning features or use of this software
     21  *    must display the following acknowledgement:
     22  *	This product includes software developed by Softweyr LLC, the
     23  *      University of California, Berkeley, and its contributors.
     24  * 4. Neither the name of the University nor the names of its contributors
     25  *    may be used to endorse or promote products derived from this software
     26  *    without specific prior written permission.
     27  *
     28  * THIS SOFTWARE IS PROVIDED BY SOFTWEYR LLC, THE REGENTS AND CONTRIBUTORS
     29  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     30  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
     31  * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL SOFTWEYR LLC, THE
     32  * REGENTS, OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     33  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
     34  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     35  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
     36  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
     37  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     38  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     39  *
     40  * Original version ID:
     41  * FreeBSD: src/lib/libc/string/wcstok.c,v 1.1 2002/09/07 08:16:57 tjr Exp
     42  */
     43 
     44 #include <sys/cdefs.h>
     45 #if defined(LIBC_SCCS) && !defined(lint)
     46 __RCSID("$NetBSD: wcstok.c,v 1.3 2003/07/10 08:50:48 tshiozak Exp $");
     47 #endif
     48 
     49 #include <assert.h>
     50 #include <wchar.h>
     51 
     52 wchar_t *
     53 wcstok(s, delim, last)
     54 	wchar_t * __restrict s;
     55 	const wchar_t * __restrict delim;
     56 	wchar_t ** __restrict last;
     57 {
     58 	const wchar_t *spanp;
     59 	wchar_t c, sc;
     60 	wchar_t *tok;
     61 
     62 	/* s may be NULL */
     63 	_DIAGASSERT(delim != NULL);
     64 	_DIAGASSERT(last != NULL);
     65 
     66 	if (s == NULL && (s = *last) == NULL)
     67 		return (NULL);
     68 
     69 	/*
     70 	 * Skip (span) leading delimiters (s += wcsspn(s, delim), sort of).
     71 	 */
     72 cont:
     73 	c = *s++;
     74 	for (spanp = delim; (sc = *spanp++) != L'\0';) {
     75 		if (c == sc)
     76 			goto cont;
     77 	}
     78 
     79 	if (c == L'\0') {	/* no non-delimiter characters */
     80 		*last = NULL;
     81 		return (NULL);
     82 	}
     83 	tok = s - 1;
     84 
     85 	/*
     86 	 * Scan token (scan for delimiters: s += wcscspn(s, delim), sort of).
     87 	 * Note that delim must have one NUL; we stop if we see that, too.
     88 	 */
     89 	for (;;) {
     90 		c = *s++;
     91 		spanp = delim;
     92 		do {
     93 			if ((sc = *spanp++) == c) {
     94 				if (c == L'\0')
     95 					s = NULL;
     96 				else
     97 					s[-1] = L'\0';
     98 				*last = s;
     99 				return (tok);
    100 			}
    101 		} while (sc != L'\0');
    102 	}
    103 	/* NOTREACHED */
    104 }
    105