lib/mbspbrk.c

   1 /* Searching a string for a character among a given set of characters.
   2    Copyright (C) 1999, 2002, 2006-2021 Free Software Foundation, Inc.
   3    Written by Bruno Haible <bruno@clisp.org>, 2007.
   4
   5    This program is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 #include <config.h>
  19
  20 /* Specification.  */
  21 #include <string.h>
  22
  23 #include "mbuiter.h"
  24
  25 /* Find the first occurrence in the character string STRING of any character
  26    in the character string ACCEPT.  Return the pointer to it, or NULL if none
  27    exists.  */
  28 char *
  29 mbspbrk (const char *string, const char *accept)
  30 {
  31   /* Optimize two cases.  */
  32   if (accept[0] == '\0')
  33     return NULL;
  34   if (accept[1] == '\0')
  35     return mbschr (string, accept[0]);
  36   /* General case.  */
  37   if (MB_CUR_MAX > 1)
  38     {
  39       mbui_iterator_t iter;
  40
  41       for (mbui_init (iter, string); mbui_avail (iter); mbui_advance (iter))
  42         {
  43           if (mb_len (mbui_cur (iter)) == 1)
  44             {
  45               if (mbschr (accept, * mbui_cur_ptr (iter)))
  46                 return (char *) mbui_cur_ptr (iter);
  47             }
  48           else
  49             {
  50               mbui_iterator_t aiter;
  51
  52               for (mbui_init (aiter, accept);
  53                    mbui_avail (aiter);
  54                    mbui_advance (aiter))
  55                 if (mb_equal (mbui_cur (aiter), mbui_cur (iter)))
  56                   return (char *) mbui_cur_ptr (iter);
  57             }
  58         }
  59       return NULL;
  60     }
  61   else
  62     return strpbrk (string, accept);
  63 }