Line data    Source code

       1             : /* Case-insensitive buffer comparator.
       2             :    Copyright (C) 1996, 1997, 2000, 2003, 2006 Free Software Foundation, Inc.
       3             : 
       4             :    This program is free software: you can redistribute it and/or modify
       5             :    it under the terms of the GNU General Public License as published by
       6             :    the Free Software Foundation; either version 3 of the License, or
       7             :    (at your option) any later version.
       8             : 
       9             :    This program 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
      12             :    GNU General Public License for more details.
      13             : 
      14             :    You should have received a copy of the GNU General Public License
      15             :    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
      16             : 
      17             : /* Written by Jim Meyering.  */
      18             : 
      19             : #include <config.h>
      20             : 
      21             : #include "memcasecmp.h"
      22             : 
      23             : #include <ctype.h>
      24             : #include <limits.h>
      25             : 
      26             : /* Like memcmp, but ignore differences in case.
      27             :    Convert to upper case (not lower) before comparing so that
      28             :    join -i works with sort -f.  */
      29             : 
      30             : int
      31          21 : memcasecmp (const void *vs1, const void *vs2, size_t n)
      32             : {
      33             :   size_t i;
      34          21 :   char const *s1 = vs1;
      35          21 :   char const *s2 = vs2;
      36          26 :   for (i = 0; i < n; i++)
      37             :     {
      38           7 :       unsigned char u1 = s1[i];
      39           7 :       unsigned char u2 = s2[i];
      40           7 :       int U1 = toupper (u1);
      41           7 :       int U2 = toupper (u2);
      42           7 :       int diff = (UCHAR_MAX <= INT_MAX ? U1 - U2
      43             :                   : U1 < U2 ? -1 : U2 < U1);
      44           7 :       if (diff)
      45           2 :         return diff;
      46             :     }
      47          19 :   return 0;
      48             : }