lib/wcscasecmp-impl.h

   1 /* Compare two wide strings ignoring case.
   2    Copyright (C) 1999, 2011-2021 Free Software Foundation, Inc.
   3    Written by Bruno Haible <bruno@clisp.org>, 2011.
   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 int
  19 wcscasecmp (const wchar_t *s1, const wchar_t *s2)
  20 {
  21   for (;;)
  22     {
  23       wchar_t wc1 = towlower (*s1++);
  24       wchar_t wc2 = towlower (*s2++);
  25       if (wc1 != (wchar_t)'\0' && wc1 == wc2)
  26         continue;
  27       /* Note that wc1 and wc2 each have at most 31 bits.  */
  28       return (int)wc1 - (int)wc2;
  29              /* > 0 if wc1 > wc2, < 0 if wc1 < wc2,
  30                 = 0 if wc1 and wc2 are both '\0'.  */
  31     }
  32 }