Get the __FILE__ constant for a function's caller in PHP

Question

I know the __FILE__ magic constant in PHP will turn into the full path and filename of the currently executing file. But is there a way I can get the same informati

Answer 1

debug_backtrace() is your friend

That's what we use to dump the full stack trace for the current line. To adjust it to your case, ignore the top of $trace array.

class Util_Debug_ContextReader {
    private static function the_trace_entry_to_return() {
        $trace = debug_backtrace();

        for ($i = 0; $i < count($trace); ++$i) {
            if ('debug' == $trace[$i]['function']) {
                if (isset($trace[$i + 1]['class'])) {
                    return array(
                        'class' => $trace[$i + 1]['class'],
                        'line' => $trace[$i]['line'],
                    );
                }

                return array(
                    'file' => $trace[$i]['file'],
                    'line' => $trace[$i]['line'],
                );
            }
        }

        return $trace[0];
    }

    /**
     * @return string
     */
    public function current_module() {
        $trace_entry = self::the_trace_entry_to_return();

        if (isset($trace_entry['class']))
            return 'class '. $trace_entry['class'];
        else
            return 'file '. $trace_entry['file'];

        return 'unknown';
    }

    public function current_line_number() {
        $trace_entry = self::the_trace_entry_to_return();
        if (isset($trace_entry['line'])) return $trace_entry['line'];
        return 'unknown';
    }
}