use the same wp-config.php across multiple dev setups

gistfile1.php

<?php

$domain = $_SERVER[HTTP_HOST];

if ($domain === '') : // If is live enviroment
    define('DB_NAME', 'our_live_db');
    define('DB_USER', 'our_live_user');
    define('DB_PASSWORD', 'our_live_password');
    define('DB_HOST', 'localhost');
elseif () : // If is staging enviroment
    define('DB_NAME', 'our_staging_db');
    define('DB_USER', 'our_staging_user');
    define('DB_PASSWORD', 'our_staging_password');
    define('DB_HOST', 'localhost');
else () : // If none, fallback to these
    define('DB_NAME', 'fallback_db');
    define('DB_USER', 'fallback_user'); // Usually 'root'
    define('DB_PASSWORD', 'fallback_password'); // Usually 'root' too
    define('DB_HOST', 'localhost');
endif;

?>