I need a script to extract the database details from the wp-config.php file so I could keep the logon details in one location when I was coding something outside the WP framework.
I came up with a class that does this, connects to mysql and selects the database. There are three connection options: PDO, mySQLi or the procedural mysql_connect().
Here’s the class:
<?php
/**
* This class pulls the database logon information out of wp-config.
* It then evals the settings it finds into PHP and then makes the
* database connection.
*
* Acts as a Singleton.
*
* @package wpConfigConnection
* @author Mark Flint
* @link www.bluecubeinteractive.com
* @copyright Please just leave this PHPDoc header in place.
*/
Class wpConfigConnection {
/**
* @var object $_singleton This is either null in the case that this class has not been
* called yet, or an instance of the class object if the class has been called.
*
* @access public
*/
private static $_singleton;
/**
* @var resource $_con The connection.
* @access public
*/
public $_con;
/**
* The wp-config.php file var
* @var string $str The string that the file is brought into.
* @access private
*/
private $str;
/**
* @var $filePath Path to wp-config.php file
* @access private
*/
private $filePath;
/**
* @var array Array of constant names used by wp-config.php for the
* logon details
* @access private
*/
private $paramA=array('DB_NAME','DB_USER','DB_PASSWORD','DB_HOST');
/**
* @var bool $database Can check this var to see if your database was connected successfully
*/
public $_database;
/**
* Constructor. This function pulls everything together and makes it happen.
* This could be unraveled to make the whole thing more flexible later.
*
* @param string $filePath Path to wp-config.php file
* @access private
*/
private function __construct($type=1,$filePath='./wp-config.php'){
$this->filePath=$filePath;
$this->getFile();
$this->serverBasedCondition();
/**
* eval the WP contants into PHP
*/
foreach ($this->paramA as $p) {
$this->evalParam('define(\''.$p.'\'','\');');
}
switch ($type) {
default:
case 1:
$this->conMySQL_Connect();
break;
case 2:
$this->conPDO();
break;
case 3:
$this->conMySQLi();
break;
}
}
/**
* Make the connection using mysql_connect
*/
private function conMySQL_Connect(){
try {
if (($this->_con = @mysql_connect(DB_HOST, DB_USER, DB_PASSWORD)) == false){
throw new Exception ('Could not connect to mySQL. ' . mysql_error());
}
} catch (Exception $e){
exit ('Error on line ' . $e->getLine(). ' in ' . $e->getFile() . ': ' . $e->getMessage());
}
try {
if (($this->_database = mysql_select_db(DB_NAME, $this->_con)) == false){
throw new Exception ('Could not select database. ' . mysql_error());
}
} catch (Exception $e){
exit ('Error on line ' . $e->getLine(). ' in ' . $e->getFile() . ': ' . $e->getMessage());
}
}
/**
* Make the connection using mySQLi
*/
private function conMySQLi(){
$this->_con = @new mysqli(DB_HOST,DB_USER,DB_PASSWORD,DB_NAME);
if (mysqli_connect_errno()){
exit ('MySQLi connection failed: ' . mysqli_connect_error());
}
}
/**
* Make the connection using PDO
*/
private function conPDO(){
try {
$dsn = 'mysql:host=' . DB_HOST . ';dbname=' . DB_NAME;
$this->_con = @new PDO($dsn, DB_USER, DB_PASSWORD);
} catch (PDOException $e) {
exit ('Error on line ' . $e->getLine(). ' in ' . $e->getFile() . ': ' . $e->getMessage() );
}
}
/**
* Read the wp-config.php file into a string
*
* @access private
*/
private function getFile() {
try {
$this->str = @file_get_contents($this->filePath);
if ($this->str == false){
throw new Exception ('Failed to read file (' . $this->filePath . ') into string.');
}
} catch (Exception $e) {
exit ('Error on line ' . $e->getLine(). ' in ' . $e->getFile() . ': ' . $e->getMessage() );
}
}
/**
* Get the logon parameter and evaluate it into PHP.
* Eg, eval("define('DB_NAME', 'm4j3lub3_wordpress');");
*
* @param string $pre This defines what to look for at the start of a logon parameter
* definition. Eg, if you are looking for "define('DB_NAME', 'm4j3lub3_wordpress');"
* then the $pre bit would be "define('DB_NAME'".
*
* @param string $post Like $pre, this defines what to look for at the end of the logon
* parameter definition. In the case of WordPress it is always going to be "');"
*
* @access private
*/
private function evalParam($pre,$post){
$str=$this->str;
$str1=substr($str,strpos($str,$pre));
$str1=substr($str1,0,strpos($str1,$post) + strlen($post));
eval($str1);
}
/**
* Grab the right code block if there are more than one set of definitions
*
* Sets $this->str to be the right code block
*
* Used for when there are conditional settings based on local or remote configuration,
* using the condition: if ($_SERVER['HTTP_HOST']=='localhost') { ...
*
* @access private
*/
private function serverBasedCondition(){
if(strpos($this->str, '$_SERVER["HTTP_HOST"]') || strpos($this->str, '$_SERVER[\'HTTP_HOST\']')){
if(strpos($this->str, '$_SERVER["HTTP_HOST"]')){
// case of double quotes - get a substring
$this->str = substr($this->str, strpos($this->str,'$_SERVER["HTTP_HOST"]'));
} elseif(strpos($this->str, '$_SERVER[\'HTTP_HOST\']')){
// case of single quotes - get a substring
$this->str = substr($this->str, strpos($this->str,'$_SERVER[\'HTTP_HOST\']'));
}
// substring from 1st occurance of {
$this->str = substr($this->str, strpos($this->str,'{')+1);
if ($_SERVER['HTTP_HOST']=='local.dev') {
// local - substring from start to 1st occurance of } - this is now the block
$this->str = substr($this->str, 0, strpos($this->str, '}') - 1);
} else {
// remote - substring from the else condition
$this->str = substr($this->str, strpos($this->str, '{')+1);
$this->str = substr($this->str, 0, strpos($this->str, '}') - 1);
}
// replace all double quote with single to make it easier to find the param definitions
$this->str=str_replace('"','\'',$this->str);
}
}
/**
* Return an instance of the class based on type of connection passed
*
* $types are:
* 1 = Procedural connection using mysql_connect()
* 2 = OOP connection using PHP Data Objects (PDO)
* 3 = OOP connection using mySQLi
*
* @return resource Database connection
* @access private
*/
private static function returnInstance($type) {
if (is_null(self::$_singleton)){
self::$_singleton = new wpConfigConnection($type);
}
return self::$_singleton;
}
/**
* Action the return of the instance based on Procedural connection using mysql_connect()
*
* @access public
* @return resource Procedural connection using mysql_connect()
*/
public static function getInstance(){
return self::returnInstance(1);
}
/**
* Action the return of the instance based on OOP connection using PDO
*
* @access public
* @return resource OOP connection using PHP Data Objects (PDO)
*/
public static function getPDOInstance(){
return self::returnInstance(2);
}
/**
* Action the return of the instance based on OOP connection using mySQLi
*
* @access public
* @return resource OOP connection using mySQLi
*/
public static function getMySQLiInstance(){
return self::returnInstance(3);
}
}
// USAGE EXAMPLES
// mysql_connect example
$mfdb = wpConfigConnection::getInstance();
try {
$query = 'select * FROM wp_users';
$res=mysql_query($query);
if ($res==false) {
throw new Exception ('mySQL error: ' . mysql_error() . '. Query: ' .$query);
}
} catch(Exception $e) {
echo 'Error on line ' . $e->getLine(). ' in ' . $e->getFile() . ': ' . $e->getMessage();
exit;
}
while ($row=mysql_fetch_assoc($res)){
echo $row['user_login'].'<br>';
}
// PDO example, showing prepared statement with bound value
$mfdb = wpConfigConnection::getPDOInstance();
$mfdb->_con->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
$mfdb->_con->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$query = "SELECT * FROM wp_users WHERE 1=:cond";
$stmt = $mfdb->_con->prepare($query);
$stmt->bindValue(':cond',1);
$stmt->execute();
while ($row = $stmt->fetch()){
echo $row['user_login'].'<br>';
}
$mfdb->_con = null;
// mySQLi example
$mfdb = wpConfigConnection::getMySQLiInstance();
$sql = ' SELECT * FROM wp_users';
if (!$mfdb->_con->real_query($sql)){
echo 'Error in query: ' . $mfdb->_con->error;
exit;
}
if ($result = $mfdb->_con->store_result()){
while($row = $result->fetch_assoc()){
echo $row['user_login'] . '<br>';
}
}
$result->close();
?>