From 900d64ec85ab35a33cc6e9ff0e74bfd12a76be82 Mon Sep 17 00:00:00 2001
From: Hung-Chi Su <atdog.cs96@gmail.com>
Date: Sat, 7 Nov 2015 20:33:28 +0800
Subject: [PATCH] add xor function

---
 lib/string_ext.rb | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/lib/string_ext.rb b/lib/string_ext.rb
index 4228c84..4aa821f 100644
--- a/lib/string_ext.rb
+++ b/lib/string_ext.rb
@@ -1,5 +1,13 @@
 class String
-    require 'pp'
+
+    def ^( key )
+        b1 = self.unpack("C*")
+        b2 = key.unpack("C*")
+        mul = (b1.length.to_f / b2.length.to_f).ceil
+        b2 = b2 * mul
+        b1.zip(b2).map{ |a,b| a^b }.pack("C*")
+    end
+
     def fmtstr(value, index, **options)
         # initialize
         bytes = 1