* lib/securerandom.rb: new method SecureRandom#uuid

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8@21869 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 10 insertions, 0 deletions

diff --git a/lib/securerandom.rb b/lib/securerandom.rb
index 3fd63e535f..ee9be9bde4 100644
--- a/lib/securerandom.rb
+++ b/lib/securerandom.rb
@@ -134,4 +134,14 @@ module SecureRandom
       Math.ldexp(i64 >> (64-Float::MANT_DIG), -Float::MANT_DIG)
     end
   end
+
+  # SecureRandom.uuid generates a v4 random UUID.
+  def self.uuid
+    str = self.random_bytes(16)
+    str[6] = (str[6] & 0x0f) | 0x40
+    str[8] = (str[8] & 0x3f) | 0x80
+
+    ary = str.unpack("NnnnnN")
+    "%08x-%04x-%04x-%04x-%04x%08x" % ary
+  end
 end