X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fmemcasecmp.c;h=a2e42e8ecfa60134713464cf0fa6f1781cf0b901;hb=6dca64d798f716c1ab15b35ab6afe17b3edec2b3;hp=7e4ab75875461434402b09e0d88fb58b8667b5fb;hpb=fee3da72c91404b6d627490411d13b58e29e33de;p=gnulib.git

diff --git a/lib/memcasecmp.c b/lib/memcasecmp.c
index 7e4ab7587..a2e42e8ec 100644
--- a/lib/memcasecmp.c
+++ b/lib/memcasecmp.c
@@ -1,3 +1,22 @@
+/* Case-insensitive buffer comparator.
+   Copyright (C) 1996, 1997 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+/* Jim Meyering (meyering@na-net.ornl.gov) */
+
 #ifdef HAVE_CONFIG_H
 # include <config.h>
 #endif
@@ -6,21 +25,23 @@
 #include <ctype.h>
 
 #if defined (STDC_HEADERS) || (!defined (isascii) && !defined (HAVE_ISASCII))
-#define ISASCII(c) 1
+# define IN_CTYPE_DOMAIN(c) 1
 #else
-#define ISASCII(c) isascii(c)
+# define IN_CTYPE_DOMAIN(c) isascii(c)
 #endif
-#define ISUPPER(c) (ISASCII (c) && isupper (c))
+#define ISLOWER(c) (IN_CTYPE_DOMAIN (c) && islower (c))
 
 #if _LIBC || STDC_HEADERS
-# define TOLOWER(c) tolower (c)
+# define TOUPPER(c) toupper (c)
 #else
-# define TOLOWER(c) (ISUPPER (c) ? tolower (c) : (c))
+# define TOUPPER(c) (ISLOWER (c) ? toupper (c) : (c))
 #endif
 
 #include "memcasecmp.h"
 
-/* Like memcmp, but ignore differences in case.  */
+/* Like memcmp, but ignore differences in case.
+   Convert to upper case (not lower) before comparing so that
+   join -i works with sort -f.  */
 
 int
 memcasecmp (vs1, vs2, n)
@@ -35,8 +56,8 @@ memcasecmp (vs1, vs2, n)
     {
       unsigned char u1 = *s1++;
       unsigned char u2 = *s2++;
-      if (TOLOWER (u1) != TOLOWER (u2))
-        return TOLOWER (u1) - TOLOWER (u2);
+      if (TOUPPER (u1) != TOUPPER (u2))
+        return TOUPPER (u1) - TOUPPER (u2);
     }
   return 0;
 }