lib/unistr/u-strtok.h

   1 /* Tokenize UTF-8/UTF-16/UTF-32 string.
   2    Copyright (C) 1999, 2002, 2006, 2009-2021 Free Software Foundation, Inc.
   3    Written by Bruno Haible <bruno@clisp.org>, 2002.
   4
   5    This program is free software: you can redistribute it and/or modify it
   6    under the terms of the GNU Lesser General Public License as published
   7    by 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 GNU
  13    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 UNIT *
  19 FUNC (UNIT *str, const UNIT *delim, UNIT **ptr)
  20 {
  21   if (str == NULL)
  22     {
  23       str = *ptr;
  24       if (str == NULL)
  25         return NULL; /* reminder that end of token sequence has been reached */
  26     }
  27
  28   /* Skip leading delimiters.  */
  29   str += U_STRSPN (str, delim);
  30
  31   /* Found a token?  */
  32   if (*str == 0)
  33     {
  34       *ptr = NULL;
  35       return NULL;
  36     }
  37
  38   /* Move past the token. */
  39   {
  40     UNIT *token_end = U_STRPBRK (str, delim);
  41     if (token_end)
  42       {
  43         *ptr = token_end + U_STRMBLEN (token_end);
  44         /* NUL-terminate the token.  */
  45         *token_end = 0;
  46       }
  47     else
  48       *ptr = NULL;
  49   }
  50
  51   return str;
  52 }