wordpress db dump single php file

wp-dump.php

<?php

require_once 'wp-config.php';

$dbhost = DB_HOST;
$dbuser = DB_USER;
$dbpass = DB_PASSWORD;
$dbname = DB_NAME;

$h = mysql_connect(DB_HOST, DB_USER, DB_PASSWORD);
mysql_select_db(DB_NAME);

header('Content-type: text/sql');

$backup_file = $dbname . date("Y-m-d-H-i-s") . '.sql';

header('Content-Disposition: attachment; filename="' . $backup_file . '"');

$cmd = 	'mysqldump '
	. ' --host=' . escapeshellarg($dbhost)
	. ' --user=' . escapeshellarg($dbuser)
	. ' --password=' . escapeshellarg($dbpass)
	. ' ' . escapeshellarg($dbname)
	. ' > ' . $backup_file;

passthru($cmd, $return);

if ($return) {
	echo "Some error occured.";
	exit;
}

readfile($backup_file);

unlink($backup_file);

?>