This is somewhat improved version of strnicmp() function in lib/string.c. I have implemented binary
comparison rather than linear one(which was in the older version). I am appending the patch bellow
--- 2.6.25-vanilla/lib/string.c 2008-04-17 08:19:44.000000000 +0530
+++ 2.6.25-hacked/lib/string.c 2008-05-07 23:31:57.000000000 +0530
@@ -1,24 +1,3 @@
-/*
- * linux/lib/string.c
- *
- * Copyright (C) 1991, 1992 Linus Torvalds
- */
-
-/*
- * stupid library routines.. The optimized versions should generally be found
- * as inline code in <asm-xx/string.h>
- *
- * These are buggy as well..
- *
- * * Fri Jun 25 1999, Ingo Oeser <ioe@informatik.tu-chemnitz.de>
- * - Added strsep() which will replace strtok() soon (because strsep() is
- * reentrant and should be faster). Use only strsep() in new code, please.
- *
- * * Sat Feb 09 2002, Jason Thomas <jason@topic.com.au>,
- * Matthew Hawkins <matt@mh.dropbear.id.au>
- * - Kissed strtok() goodbye
- */
-
#include <linux/types.h>
#include <linux/string.h>
#include <linux/ctype.h>
@@ -31,32 +10,43 @@
* @s2: The other string
* @len: the maximum number of characters to compare
*/
+/* This is somewhat faster
+ * method compared to the
+ * olderone (in case of a large string)
+ */
int strnicmp(const char *s1, const char *s2, size_t len)
{
- /* Yes, Virginia, it had better be unsigned */
- unsigned char c1, c2;
-
- c1 = c2 = 0;
- if (len) {
- do {
- c1 = *s1;
- c2 = *s2;
- s1++;
- s2++;
- if (!c1)
- break;
- if (!c2)
- break;
- if (c1 == c2)
- continue;
- c1 = tolower(c1);
- c2 = tolower(c2);
- if (c1 != c2)
+ /* Yes, i am keeping 'em unsigned too */
+ unsigned char c1, c2, c3, c4;
+ unsigned count = 0;
+ int flag = -1;
+
+ c1 = c2 = c3 = c4 = 0;
+
+ if(len > 0)
+ {
+ for(; count <= len/2; count++)
+ {
+ c1 = tolower(s1[count]); // well, we
+ c2 = tolower(s2[count]); // are ignoring
+ c3 = tolower(s1[len-count-1]); // cases
+ c4 = tolower(s2[len-count-1]); // thats why
+
+ if(c1 == c2)
+ {
+ if(c3 != c4)
+ {
+ flag = 1;
+ break;
+ }
+ }
+ else
break;
- } while (--len);
+ flag = 0;
+ }
}
- return (int)c1 - (int)c2;
-}
+ return flag; // return 0 for matching and
+} // nonzero for mismatch
EXPORT_SYMBOL(strnicmp);
#endif
Meet people who discuss and share your passions. Go to http://in.promos.yahoo.com/groups/bestofyahoo/
--
