lib/mbspbrk.c

   1 /* Searching a string for a character among a given set of characters.
   2    Copyright (C) 1999, 2002, 2006-2024 Free Software Foundation, Inc.
   3    Written by Bruno Haible <bruno@clisp.org>, 2007.
   4
   5    This file is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU Lesser General Public License as
   7    published by the Free Software Foundation, either version 3 of the
   8    License, or (at your option) any later version.
   9
  10    This file 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 Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser 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 <stdlib.h>
  24
  25 #if GNULIB_MCEL_PREFER
  26 # include "mcel.h"
  27 #else
  28 # include "mbuiterf.h"
  29 #endif
  30
  31 /* Find the first occurrence in the character string STRING of any character
  32    in the character string ACCEPT.  Return the pointer to it, or NULL if none
  33    exists.  */
  34 char *
  35 mbspbrk (const char *string, const char *accept)
  36 {
  37   /* Optimize two cases.  */
  38   if (accept[0] == '\0')
  39     return NULL;
  40   if (accept[1] == '\0')
  41     return mbschr (string, accept[0]);
  42   /* General case.  */
  43   if (MB_CUR_MAX > 1)
  44     {
  45       char const *iter = string;
  46 #if GNULIB_MCEL_PREFER
  47       mcel_t a, g;
  48       for (; *iter; iter += g.len)
  49         {
  50           g = mcel_scanz (iter);
  51           if (g.len == 1)
  52             {
  53               if (mbschr (accept, *iter))
  54                 return (char *) iter;
  55             }
  56           else
  57             for (char const *aiter = accept; *aiter; aiter += a.len)
  58               {
  59                 a = mcel_scanz (aiter);
  60                 if (mcel_cmp (a, g) == 0)
  61                   return (char *) iter;
  62               }
  63         }
  64 #else
  65       mbuif_state_t state;
  66       for (mbuif_init (state); mbuif_avail (state, iter); )
  67         {
  68           mbchar_t cur = mbuif_next (state, iter);
  69           if (mb_len (cur) == 1)
  70             {
  71               if (mbschr (accept, *iter))
  72                 return (char *) iter;
  73             }
  74           else
  75             {
  76               mbuif_state_t astate;
  77               const char *aiter;
  78               for (mbuif_init (astate), aiter = accept;
  79                    mbuif_avail (astate, aiter); )
  80                 {
  81                   mbchar_t acur = mbuif_next (astate, aiter);
  82                   if (mb_equal (acur, cur))
  83                     return (char *) iter;
  84                   aiter += mb_len (acur);
  85                 }
  86             }
  87           iter += mb_len (cur);
  88         }
  89 #endif
  90       return NULL;
  91     }
  92   else
  93     return strpbrk (string, accept);
  94 }