lib/wcsncasecmp-impl.h

   1 /* Compare two wide strings ignoring case.
   2    Copyright (C) 1999, 2011-2024 Free Software Foundation, Inc.
   3    Written by Bruno Haible <bruno@clisp.org>, 2011.
   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 int
  19 wcsncasecmp (const wchar_t *s1, const wchar_t *s2, size_t n)
  20 {
  21   for (; n > 0;)
  22     {
  23       wchar_t wc1 = towlower (*s1++);
  24       wchar_t wc2 = towlower (*s2++);
  25       if (wc1 != (wchar_t)'\0' && wc1 == wc2)
  26         {
  27           n--;
  28           continue;
  29         }
  30       /* Note that wc1 and wc2 each have at most 31 bits.  */
  31       return (int)wc1 - (int)wc2;
  32              /* > 0 if wc1 > wc2, < 0 if wc1 < wc2,
  33                 = 0 if wc1 and wc2 are both '\0'.  */
  34     }
  35   return 0;
  36 }