__FILE__

PHP Magic Constants: __LINE__, __FILE__, __DIR__, __FUNCTION__, __CLASS__, __METHOD__, and __NAMESPACE__

I’ve been using __FILE__ for years, but I never thought to look for its siblings.

echo ' line:'. __LINE__ .' file:'. __FILE__ .' directory:'. __DIR__ .' function:'. __FUNCTION__ .' class:'. __CLASS__ .' method:'. __METHOD__ .' namespace:'. __NAMESPACE__;

I feel as though I should have noticed these earlier; they’re clearly referenced in the docs for debug_backtrace(), after all.