<?php

$USER="user";
$PASSWD="password";
$DATABASE="user_db";

$FILENAME = "backup-" . date("d-m-Y") . ".sql.gz";
$MIME = "application/x-gzip";

header( "Content-Type: " . $MIME );
header( 'Content-Disposition: attachment; filename="' . $FILENAME . '"' );

$CMD = "mysqldump -u $USER --password=$PASSWD $DATABASE | gzip --best";

passthru( $CMD );

exit(0);
?>