compiler/stdc/strcasecmp.c

   1 /*
   2     Copyright © 1995-2012, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     POSIX.1-2008 function strcasecmp().
   6 */
   7
   8 #include <ctype.h>
   9
  10 /*****************************************************************************
  11
  12     NAME */
  13 #include <string.h>
  14
  15         int strcasecmp (
  16
  17 /*  SYNOPSIS */
  18         const char * str1,
  19         const char * str2)
  20
  21 /*  FUNCTION
  22         Calculate str1 - str2 ignoring case.
  23
  24     INPUTS
  25         str1, str2 - Strings to compare
  26
  27     RESULT
  28         The difference of the strings. The difference is 0, if both are
  29         equal, < 0 if str1 < str2 and > 0 if str1 > str2. Note that
  30         it may be greater then 1 or less than -1.
  31
  32     NOTES
  33         This function is not part of a library and may thus be called
  34         any time.
  35
  36     EXAMPLE
  37
  38     BUGS
  39
  40     SEE ALSO
  41
  42     INTERNALS
  43
  44 ******************************************************************************/
  45 {
  46     int diff;
  47
  48     /* No need to check *str2 since: a) str1 is equal str2 (both are 0),
  49         then *str1 will terminate the loop b) str1 and str2 are not equal
  50         (eg. *str2 is 0), then the diff part will be FALSE. I calculate
  51         the diff first since a) it's more probable that the first chars
  52         will be different and b) I don't need to initialize diff then. */
  53     while (!(diff = tolower (*str1) - tolower (*str2)) && *str1)
  54     {
  55         /* advance both strings. I do that here, since doing it in the
  56             check above would mean to advance the strings once too often */
  57         str1 ++;
  58         str2 ++;
  59     }
  60
  61     /* Now return the difference. */
  62     return diff;
  63 } /* strcasecmp */