Backup e restauração do banco de dados MySQL em PHP

<?php
define("BACKUP_PATH", "/home/abdul/");

$server_name   = "localhost";
$username      = "root";
$password      = "root";
$database_name = "world_copy";
$date_string   = date("Ymd");

$cmd = "mysqldump --routines -h {$server_name} -u {$username} -p{$password} {$database_name} > " . BACKUP_PATH . "{$date_string}_{$database_name}.sql";

exec($cmd);
?>

<?php

$restore_file  = "/home/abdul/20140306_world_copy.sql";
$server_name   = "localhost";
$username      = "root";
$password      = "root";
$database_name = "test_world_copy";

$cmd = "mysql -h {$server_name} -u {$username} -p{$password} {$database_name} < $restore_file";
exec($cmd);

?>