note 33948 added to function.sha1

Since SHA1 generates a whole lot of random-looking characters, I figured it can be used to generate "unique" ID's. This is the function I use in my home-rolled session management code: function generateUniqueId() { return sprintf( "%s%02d", substr( sha1( (string) time() ), mt_rand( 0, 32 ), 8 ), mt_rand( 0, 99 ) ); } As you can see, this takes a random substr of 8 characters from the SHA1 hash of the current time, and adds two random digits. This allows for a theoretical maximum of 3200 unique ID's per second (assuming the random number generator hits all possible combinations). This is only one way of generating a (hopefully) unique ID and probably not the best, but I'm hoping it may be of use to someone. ---- Manual Page -- http://www.php.net/manual/en/function.sha1.php Edit Note -- http://master.php.net/manage/user-notes.php?action=edit+33948 Delete Note -- http://master.php.net/manage/user-notes.php?action=delete+33948&report=yes Reject Note -- http://master.php.net/manage/user-notes.php?action=reject+33948&report=yes