PHP Table backup script

backup-tables.php

#!/usr/bin/php
<?php
	$config = [
		'host' => 'localhost',
		'user' => 'root',
		'pass' => '',
		'db' => 'prestashop',

		'prefix' => 'ps_',
		'tables' => [
			'address',
			'customer(.+|$)',

			'cart(.+|$)',
			'message',

			'orders',
			'order(.+)',
			'paypal(.+)',

			'product',
			'product_lang',
			'specific_price'
		],

		'name' => 'backup_%y%m%d_%H%i%s_%T.sql',
		'path' => getcwd() .'/',
		'gzip' => TRUE
	];

	$db = new mysqli($config['host'], $config['user'], $config['pass'], $config['db']);

	if($db->connect_errno){
		error_log("ERROR connecting to DB: " .$db->connect_errno);
		exit(1);
	}

	$tables = $db->query("SHOW TABLES");
	if($tables->num_rows == 0){
		error_log("No tables found.");
		exit(1);
	}

	$backup_tables = array();
	$match = '/^' .$config['prefix'] .'(' .implode('|', $config['tables']) .')' .'$/';

	while($table = $tables->fetch_row()){
		$table = current($table);
		if(preg_match($match, $table)){
			$backup_tables[] = $table;
		}
	}

	if(count($backup_tables) == 0){	
		echo("No tables found in pattern, not doing backup.");
		exit(0);
	}

	echo "Preparing backup for " .count($backup_tables) ." tables...\n";
	$date_now = time();

	foreach($backup_tables as $table){
		$file = $config['name'];
		$date_matches = "dDjlNSwzWFmMntLoYyaABgGhHisuveIOPZcr";

		foreach(str_split($date_matches) as $m){
			$file = str_replace('%' .$m, date("$m", $date_now), $file);
		}

		$file = str_replace("%T", $table, $file);
		echo "> " .$file ."\n";

		$time = microtime(TRUE);

		$cmd = "mysqldump"
			." --host=" .$config['host'] 
			." --user=" .$config['user'] 
			." --password=" .$config['pass'] 
			." " .$config['db'] 
			." " .$table;

		exec($cmd ." > " .$config['path'] .$file);

		$time = floor((microtime(TRUE) - $time) * 1000);
		echo "Done in $time ms.";

		if($config['gzip']){
			echo " Compressing... ";
			$time = microtime(TRUE);

			exec("gzip " .$config['path'] .$file);
			$time = floor((microtime(TRUE) - $time) * 1000);
			echo "Done in $time ms.";
		}

		echo "\n";
	}
?>