php配置变量写入配置文件的方法

$configfile = @file_get_contents('./config.inc.php');
			$configfile = trim($configfile);
			$configfile = preg_replace("/[$]dbhost\s*\=\s*[\"'].*?[\"'];/is", "\$dbhost = '$dbhost';", $configfile);
			$configfile = preg_replace("/[$]dbuser\s*\=\s*[\"'].*?[\"'];/is", "\$dbuser = '$dbuser';", $configfile);
			$configfile = preg_replace("/[$]dbpw\s*\=\s*[\"'].*?[\"'];/is", "\$dbpw = '$dbpw';", $configfile);
			$configfile = preg_replace("/[$]dbname\s*\=\s*[\"'].*?[\"'];/is", "\$dbname = '$dbname';", $configfile);
			$configfile = preg_replace("/[$]adminemail\s*\=\s*[\"'].*?[\"'];/is", "\$adminemail = '$adminemail';", $configfile);
			$configfile = preg_replace("/[$]tablepre\s*\=\s*[\"'].*?[\"'];/is", "\$tablepre = '$tablepre';", $configfile);
			$configfile = preg_replace("/[$]cookiepre\s*\=\s*[\"'].*?[\"'];/is", "\$cookiepre = '".random(3)."_';", $configfile);
 
			@file_put_contents('./config.inc.php', $configfile);