Help! - Custom Joomla Installer

I have written a custom joomla installer it all works fine except for setting up the configuration.php file with the database information below is my code:

if (!-r $cfile) { &run_as_domain_user($d, "cp ".quotemeta($cfileorig)." ". quotemeta($cfile)); local $lref = &read_file_lines_as_domain_user($d, $cfile); local $l; foreach $l (@$lref) { if ($l =~ /^define\('$db',/) { $l = "define('$db', '$dbname');"; } if ($l =~ /^define\('$user',/) { $l = "define('$user', '$dbuser');"; } if ($l =~ /^define\('$host',/) { $l = "define('$host', '$dbhost');"; } if ($l =~ /^define\('$password',/) { $l = "define('$password', '". &php_quotemeta($dbpass)."');"; } } &flush_file_lines_as_domain_user($d, $cfile); }

The joomla configuration.php looks like this:

/* Database Settings */
public $dbtype = ‘mysqli’; // Normally mysqli
public $host = ‘localhost’; // This is normally set to localhost
public $user = ‘’; // DB username
public $password = ‘’; // DB password
public $db = ‘’; // DB database name
public $dbprefix = ‘jos_’; // Do not change unless you need to!

Any help would be appreciated!