function name($param, $line = __LINE__, $file = __FILE__) {};

Question

Hi there,

Is it possible to have a function automatically contain the line number and the file that the function was CALLED in,

as if i call __LINE__ or __FILE__ in the function it will use the line and file the function definition is in.

but i dont want to have to pass __LINE__ and __FILE__ into the function every time.

so if i set them as the default params, do they come from the function definition, or where it is being called from?

Answer 1

Doing what you suggest doesn't seem to work.

You can do it like this, but I'm not sure why you want to do it and that there isn't a better approach to what you are trying to achieve - see Wrikken's answer.

<?php

function test() {
    $backtrace = debug_backtrace();
    $last = $backtrace[0];
    echo "{$last['function']}() called from {$last['file']} line {$last['line']}\r\n"; 
}



test();

Answer 2

The only way would be using debug_backtrace(), but as the name says: it is for debugging. Your code should not attach any meaning or functionality in production based on where/when it's called.

Answer 3

if you want to use this information in some kind of error message, there is a function trigger_error() which will raise PHP native error, so, therefore, it will be shown in usual PHP manner - with filename, line number and supplied text.

Most neat feature of this function is behaving according to current error handling settings:

ini_set('display_errors',1);
trigger_error("Horrible bug found!");

will print out directly to screen an error message like this:

Notice: Horrible bug found! in /path/file.php on line 2

very handy for developing
while this code

ini_set('display_errors',0);
ini_set('log_errors',1);
trigger_error("Horrible bug found!");

will be put into error log for the future reference
obligatory for the production