newlib/libc/posix/collcmp.c

   1 /*
   2  * Copyright (C) 1996 by Andrey A. Chernov, Moscow, Russia.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  */
  26
  27 #include <sys/cdefs.h>
  28
  29 #define ASCII_COMPATIBLE_COLLATE        /* see share/colldef */
  30
  31 #include <string.h>
  32 #include "collate.h"
  33 #ifndef ASCII_COMPATIBLE_COLLATE
  34 #include <ctype.h>
  35 #endif
  36
  37 /*
  38  * Compare two characters converting collate information
  39  * into ASCII-compatible range, it allows to handle
  40  * "[a-z]"-type ranges with national characters.
  41  */
  42
  43 int __collate_range_cmp (
  44         int c1,
  45         int c2
  46 )
  47 {
  48         static char s1[2], s2[2];
  49         int ret;
  50 #ifndef ASCII_COMPATIBLE_COLLATE
  51         int as1, as2, al1, al2;
  52 #endif
  53
  54         c1 &= UCHAR_MAX;
  55         c2 &= UCHAR_MAX;
  56         if (c1 == c2)
  57                 return (0);
  58
  59 #ifndef ASCII_COMPATIBLE_COLLATE
  60         as1 = isascii(c1);
  61         as2 = isascii(c2);
  62         al1 = isalpha(c1);
  63         al2 = isalpha(c2);
  64
  65         if (as1 || as2 || al1 || al2) {
  66                 if ((as1 && as2) || (!al1 && !al2))
  67                         return (c1 - c2);
  68                 if (al1 && !al2) {
  69                         if (isupper(c1))
  70                                 return ('A' - c2);
  71                         else
  72                                 return ('a' - c2);
  73                 } else if (al2 && !al1) {
  74                         if (isupper(c2))
  75                                 return (c1 - 'A');
  76                         else
  77                                 return (c1 - 'a');
  78                 }
  79         }
  80 #endif
  81         s1[0] = c1;
  82         s2[0] = c2;
  83         if ((ret = strcoll(s1, s2)) != 0)
  84                 return (ret);
  85         return (c1 - c2);
  86 }