1  /* Compare at most N wide characters of two strings without taking care
       2     for the case.
       3     Copyright (C) 1992-2023 Free Software Foundation, Inc.
       4     This file is part of the GNU C Library.
       5  
       6     The GNU C Library is free software; you can redistribute it and/or
       7     modify it under the terms of the GNU Lesser General Public
       8     License as published by the Free Software Foundation; either
       9     version 2.1 of the License, or (at your option) any later version.
      10  
      11     The GNU C Library is distributed in the hope that it will be useful,
      12     but WITHOUT ANY WARRANTY; without even the implied warranty of
      13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      14     Lesser General Public License for more details.
      15  
      16     You should have received a copy of the GNU Lesser General Public
      17     License along with the GNU C Library; if not, see
      18     <https://www.gnu.org/licenses/>.  */
      19  
      20  #ifdef HAVE_CONFIG_H
      21  # include <config.h>
      22  #endif
      23  
      24  #include <wchar.h>
      25  #include <wctype.h>
      26  
      27  #ifndef weak_alias
      28  # define __wcsncasecmp wcsncasecmp
      29  # define TOLOWER(Ch) towlower (Ch)
      30  #else
      31  # ifdef USE_IN_EXTENDED_LOCALE_MODEL
      32  #  define __wcsncasecmp __wcsncasecmp_l
      33  #  define TOLOWER(Ch) __towlower_l ((Ch), loc)
      34  # else
      35  #  define TOLOWER(Ch) towlower (Ch)
      36  # endif
      37  #endif
      38  
      39  #ifdef USE_IN_EXTENDED_LOCALE_MODEL
      40  # define LOCALE_PARAM , locale_t loc
      41  #else
      42  # define LOCALE_PARAM
      43  #endif
      44  
      45  /* Compare no more than N wide characters of S1 and S2,
      46     ignoring case, returning less than, equal to or
      47     greater than zero if S1 is lexicographically less
      48     than, equal to or greater than S2.  */
      49  int
      50  __wcsncasecmp (const wchar_t *s1, const wchar_t *s2, size_t n LOCALE_PARAM)
      51  {
      52    wint_t c1, c2;
      53  
      54    if (s1 == s2 || n == 0)
      55      return 0;
      56  
      57    do
      58      {
      59        c1 = (wint_t) TOLOWER (*s1++);
      60        c2 = (wint_t) TOLOWER (*s2++);
      61        if (c1 == L'\0' || c1 != c2)
      62  	return c1 - c2;
      63      } while (--n > 0);
      64  
      65    return c1 - c2;
      66  }
      67  #ifndef __wcsncasecmp
      68  weak_alias (__wcsncasecmp, wcsncasecmp)
      69  #endif