EDIT

<?php

/**

 * Created by PhpStorm.

 * User: andreas

 * Date: 11.01.18

 * Time: 12:39

 *

 * Execute .e.g as

 *

 *   php db_debug.php.inc sites/cyprus/settings.php

 *

 */

$setting_file = $argv[1];

print ("Running db_debug.php with settings from " . $setting_file . "\n");

require($setting_file);

print("db configuration:\n");

print_r($databases);

print ("trying to connect to default db ...\n");

$db_test_settings = $databases["default"]["default"];

$mysqli = mysqli_connect($db_test_settings["host"], $db_test_settings["username"], $db_test_settings["password"], $db_test_settings["database"]);

if ($mysqli->connect_errno) {

  echo "Failed to connect to MySQL: (" . $mysqli->connect_errno . ") " . $mysqli->connect_error;

}

echo "Connection opened: " . $mysqli->host_info . "\n";

$res = $mysqli->query("SELECT * FROM " .$db_test_settings["prefix"]. "system");

echo "system table ...\n";

for ($row_no = $res->num_rows - 1; $row_no >= 0; $row_no--) {

  $res->data_seek($row_no);

  $row = $res->fetch_assoc();

  echo " filename = " . $row['filename'] . "\n";

}