wcsmbs/wcstok.c

   1 /* Copyright (C) 1995-2023 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <wchar.h>
  19 #include <errno.h>
  20
  21
  22 /* Parse WCS into tokens separated by characters in DELIM.  If WCS is
  23    NULL, the last string wcstok() was called with is used.  */
  24 wchar_t *
  25 wcstok (wchar_t *wcs, const wchar_t *delim, wchar_t **save_ptr)
  26 {
  27   wchar_t *result;
  28
  29   if (wcs == NULL)
  30     {
  31       if (*save_ptr == NULL)
  32         {
  33           __set_errno (EINVAL);
  34           return NULL;
  35         }
  36       else
  37         wcs = *save_ptr;
  38     }
  39
  40   /* Scan leading delimiters.  */
  41   wcs += wcsspn (wcs, delim);
  42   if (*wcs == L'\0')
  43     {
  44       *save_ptr = NULL;
  45       return NULL;
  46     }
  47
  48   /* Find the end of the token.  */
  49   result = wcs;
  50   wcs = wcspbrk (result, delim);
  51   if (wcs == NULL)
  52     /* This token finishes the string.  */
  53     *save_ptr = NULL;
  54   else
  55     {
  56       /* Terminate the token and make *SAVE_PTR point past it.  */
  57       *wcs = L'\0';
  58       *save_ptr = wcs + 1;
  59     }
  60   return result;
  61 }