lib/libc/string/wcstok.c

   1 /* $NetBSD: wcstok.c,v 1.4 2012/06/25 22:32:46 abs 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@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 1.4 2012/06/25 22:32:46 abs Exp $");
  47 #endif
  48
  49 #include <assert.h>
  50 #include <wchar.h>
  51
  52 wchar_t *
  53 wcstok(wchar_t * __restrict s, const wchar_t * __restrict delim,
  54     wchar_t ** __restrict last)
  55 {
  56         const wchar_t *spanp;
  57         wchar_t c, sc;
  58         wchar_t *tok;
  59
  60         /* s may be NULL */
  61         _DIAGASSERT(delim != NULL);
  62         _DIAGASSERT(last != NULL);
  63
  64         if (s == NULL && (s = *last) == NULL)
  65                 return (NULL);
  66
  67         /*
  68          * Skip (span) leading delimiters (s += wcsspn(s, delim), sort of).
  69          */
  70 cont:
  71         c = *s++;
  72         for (spanp = delim; (sc = *spanp++) != L'\0';) {
  73                 if (c == sc)
  74                         goto cont;
  75         }
  76
  77         if (c == L'\0') {       /* no non-delimiter characters */
  78                 *last = NULL;
  79                 return (NULL);
  80         }
  81         tok = s - 1;
  82
  83         /*
  84          * Scan token (scan for delimiters: s += wcscspn(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 == L'\0')
  93                                         s = NULL;
  94                                 else
  95                                         s[-1] = L'\0';
  96                                 *last = s;
  97                                 return (tok);
  98                         }
  99                 } while (sc != L'\0');
 100         }
 101         /* NOTREACHED */
 102 }