setup install like wordpress

I want to make settings to install my application like wordpress.
I tried to make a new file like wordpress.
but I have difficulty when making it.


first option :

PHP Code:

if ( ! file_exists(APPPATH.'config/my_database.php')) {

    $data = array(
    '$config["database_name"] = "my-name"',
    );
        //I'm having trouble creating a my_database file with values like this:
        //$config[username] = 'my-name';
        //$config[userpass] = 'my-pass';
        //etc.

        if ( ! write_file(APPPATH.'config/my_database.php', $data)) {
        echo 'Unable to write the file';
    } else {
        echo 'File written!';
    }
} 


second option  :

PHP Code:

if ( ! file_exists(APPPATH.'config/database.php')) {

    if (copy(APPPATH.'config/database_example.php', APPPATH.'config/database.php')) {
            // I'm having a problem here, before copying data $db['defult'] = array for database.php
            // changed according to the configuration form later.
            // I tried using the file_put_contents() function but failed.

        echo 'Copy Success';
    } else {
        echo 'Copy Failed!';
    }
} 


or if there is another way let me know

Please help and thank you