server name as global variable

gistfile1.txt

/*
Add this to your config.php file
*/

$default_global_vars = array(
    'global:domain_name' => $_SERVER['SERVER_NAME']
);

// Make this global, then add our default_global_vars to the config variables here
global $assign_to_config;
if(!isset($assign_to_config['global_vars'])) $assign_to_config['global_vars'] = array();
$assign_to_config['global_vars'] = array_merge($assign_to_config['global_vars'], $default_global_vars);

/*
Use in your template as {global:domain_name}
*/