note 68373 added to function.hash-update

A simple example on incremental file hashing: $fp = fopen($file, "r"); $ctx = hash_init('sha256'); while (!feof($fp)) { $buffer = fgets($fp, 65536); hash_update($ctx, $buffer); } $hash = hash_final($ctx, true); fclose($fp); While incremental hashing is quite slow, it's the easiest way to hash - parts of large files: I.e., a 700MB avi video uses first x bytes to store metadata, so in order to hash the avi's data only, you have to fseek to data start and use incremental hashing - streaming data if php just proxies the data - whenever it's inadequate or impossible to store the data being hashed into memory (i.e. because of their size) or on disc. ---- Server IP: 66.163.161.117 Probable Submitter: 89.102.31.40 ---- X-Spam-Status: No, hits=3.1 required=5.0 tests=DATE_MISSING,FROM_NO_LOWER autolearn=no version=2.64 ---- Manual Page -- http://www.php.net/manual/en/function.hash-update.php Edit -- http://master.php.net/note/edit/68373 Del: integrated -- http://master.php.net/note/delete/68373/integrated Del: useless -- http://master.php.net/note/delete/68373/useless Del: bad code -- http://master.php.net/note/delete/68373/bad+code Del: spam -- http://master.php.net/note/delete/68373/spam Del: non-english -- http://master.php.net/note/delete/68373/non-english Del: in docs -- http://master.php.net/note/delete/68373/in+docs Del: other reasons-- http://master.php.net/note/delete/68373 Reject -- http://master.php.net/note/reject/68373 Search -- http://master.php.net/manage/user-notes.php