How to Create a Form Updatable Config File

config.php

<?php 
$dbhost = "svr.kit-b.com";
$dbuname = "kit-b_user";
$dbpass = "kit-b_pass";
$dbname = "kit-b_db";
$prefix = "dbpref_";
$user_prefix = "userpref_";
$dbtype = "10002";
?>

index.php

<?PHP       
require_once 'config.php';

IF (ISSET($_POST["Submit"])) {

	//if data has been posted update config file
	
		$fname = "config.php";//name/path of config file
		$fhandle = fopen($fname,"r");//Open for reading only; place the file pointer at the beginning of the file.
		$content = fread($fhandle,filesize($fname));//Read from file pointer onwards
		
		//Remove unwanted elements
		$find = array('<?php','?>',';',' ','"','\n');
		$replace = array("");
		$data = str_replace($find, $replace, $content);
		
		//Create array
		$array = preg_split("/[$=]/",$data);
		array_shift($array);//remove empty first array
		
		//use odd key value in array1 as key in array2
		foreach (array_chunk($array, 2) as $pair) { 
			list($key, $value) = $pair; 
			$assoc[$key] = $value; 
		}
		
		//change array values and recreate string
		$string = "<?php \n";
		foreach ($assoc as $key => $value):
		
		 	if ($assoc[$key] != $_POST[$key]){
				$string .= '$'.$key.' = "'.trim($_POST[$key]).'";'."\n";
			}
			else{
				$string .= '$'.$key.' = "'.trim($value).'";'."\n";
			}
			
		endforeach;
		$string .= "?>";
		
		//write to file
		$fhandle = fopen($fname,"w");
		fwrite($fhandle,$string);
		fclose($fhandle);
		
		header ("Location: ".$_SERVER['PHP_SELF']);//reload page to get new form values
}
 
//header
echo "/**** <b>Author:</b> <a href='https://twitter.com/mainakibui' target='_blank'> @mainakibui </a> <br>
       **** <b>Website:</b> <a href='http://kit-b.com/' target='_blank'> www.kit-b.com </a> <br>
       **** <b>Title:</b> How to Create a Form Updatable Config File <br>
       ****/";
//header

?>
 
<form action="" method="post" name="edit_config" id="edit_config">
  <p>
    <input name="dbhost" type="text" id="dbhost" value="<?php echo $dbhost;?>"> 
    DB Host
</p>
  <p>
    <input name="dbuname" type="text" id="dbuname" value="<?php echo $dbuname;?>"> 
    DB Username
</p>
  <p>
    <input name="dbpass" type="password" id="dbpass" value="<?php echo $dbpass;?>">
  DB Pass </p>
  <p>
    <input name="dbname" type="text" id="dbname" value="<?php echo $dbname;?>">
  DB Name </p>
  <p>
    <input name="prefix" type="text" id="prefix" value="<?php echo $prefix;?>">
  DB Prefix</p>
  <p>
    <input name="user_prefix" type="text" id="user_prefix" value="<?php echo $user_prefix;?>">
  Userprefix</p>
  <p>
    <input name="dbtype" type="text" id="dbtype" value="<?php echo $dbtype;?>">
  DB Type </p>
  <p>
    <input type="submit" name="Submit" value="Save">
  </p>
</form>