note 96549 added to function.uniqid

As others below note, without prefix and without "added entropy", this function simply returns the UNIX timestamp with added microsecond counter as a hex number; it's more or less just microtime(), in hexit form. A longer and more diverse unique id in the same hexit scheme can be achieved by instead digesting uniqid() (or a series of mt_rand(), f.e.) through md5() or sha1(): <?php $unique = md5( uniqid() ); // 32 characters long $unique = sha1( uniqid() ); // 40 characters long ?> Also worth to note is that since microtime() only works on systems that have gettimeofday() present, which Windows natively DOES NOT, uniqid() might yield just the single-second-resolution UNIX timestamp in a Windows environment. ---- Server IP: 194.236.124.41 Probable Submitter: 83.227.160.33 ---- Manual Page -- http://www.php.net/manual/en/function.uniqid.php Edit -- https://master.php.net/note/edit/96549 Del: integrated -- https://master.php.net/note/delete/96549/integrated Del: useless -- https://master.php.net/note/delete/96549/useless Del: bad code -- https://master.php.net/note/delete/96549/bad+code Del: spam -- https://master.php.net/note/delete/96549/spam Del: non-english -- https://master.php.net/note/delete/96549/non-english Del: in docs -- https://master.php.net/note/delete/96549/in+docs Del: other reasons-- https://master.php.net/note/delete/96549 Reject -- https://master.php.net/note/reject/96549 Search -- https://master.php.net/manage/user-notes.php