wcsmbs/mbsncmp.c

   1 /* Copyright (C) 1995 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 Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 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 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <mbstr.h>
  20 #include <stdlib.h>
  21
  22 #define __need_wchar_t
  23 /* FIXME: should be defined in stddef.h.
  24 !!! #define __need_uwchar_t  */
  25 typedef unsigned int uwchar_t;
  26 #include <stddef.h>
  27
  28
  29 /* Compare N characters of MBS1 and MBS2.  */
  30 int
  31 mbsncmp (mbs1, mbs2, n)
  32     const char *mbs1;
  33     const char *mbs2;
  34     size_t n;
  35 {
  36   size_t len = 0;
  37   int clen1 = 0;
  38   int clen2 = 0;
  39   uwchar_t c1;
  40   uwchar_t c2;
  41
  42   if (n == 0)
  43     return 0;
  44
  45   /* Reset multibyte characters to their initial state.  */
  46   (void) mblen ((char *) NULL, 0);
  47
  48   do
  49     {
  50       clen1 = mbtowc ((wchar_t *) &c1, mbs1, MB_CUR_MAX);
  51       clen2 = mbtowc ((wchar_t *) &c2, mbs2, MB_CUR_MAX);
  52
  53       if (clen1 == 0)
  54         return clen2 == 0 ? 0 : -1;
  55       if (clen2 == 0)
  56         return 1;
  57       if (clen1 < 0 || clen2 < 0)
  58         /* FIXME: an illegal character appears.  What to do?  */
  59         return c1 - c2;
  60
  61       mbs1 += clen1;
  62       mbs2 += clen2;
  63     }
  64   while (c1 == c2 && ++len < n);
  65
  66   return len < n ? c1 - c2 : 0;
  67 }
  68