.

[gnulib.git] / lib / memcasecmp.c

diff --git a/lib/memcasecmp.c b/lib/memcasecmp.c
index 28e397b..a2e42e8 100644 (file)
--- a/lib/memcasecmp.c
+++ b/lib/memcasecmp.c
@@ -1,5 +1,5 @@
 /* Case-insensitive buffer comparator.
-   Copyright (C) 1996 Free Software Foundation, Inc.
+   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
@@ -12,8 +12,8 @@
    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., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+   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) */
 
@@ -25,21 +25,23 @@
 #include <ctype.h>
 
 #if defined (STDC_HEADERS) || (!defined (isascii) && !defined (HAVE_ISASCII))
-#define IN_CTYPE_DOMAIN(c) 1
+# define IN_CTYPE_DOMAIN(c) 1
 #else
-#define IN_CTYPE_DOMAIN(c) isascii(c)
+# define IN_CTYPE_DOMAIN(c) isascii(c)
 #endif
-#define ISUPPER(c) (IN_CTYPE_DOMAIN (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)
@@ -54,8 +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;
 }