PHP equivalent of Python's __name__ == "__main__"?

Question

As per the title, is there PHP equivalent of __name__ == "__main__"?

Is there something that would work for both scripts executed through the command line and through a web request, or would a custom function be needed?

For those unfamiliar with Python, __name__ == "__main__" allows you to define a module file, and also have some things that allow you to run it if it is the entry point. The equivalent structure in PHP would resemble this:

// SomeClass.php
<?php
class SomeClass
{
    function doStuff() {
        echo "wahey!\n";
    }
}

// python, I know.
if (__name__ == "__main__") {
    $sc = new SomeClass;
    $sc->doStuff();
}
?>

// OtherClass.php
<?php
require_once("SomeClass.php");
class OtherClass
{
    public $yep;
}
?>

// command line:
php SomeClass.php     // outputs "wahey!"
php OtherClass.php    // outputs nothing

---

Note: zerkms' answer is the best, but is not quite right - it should read:

if (!debug_backtrace()) {
    // do useful stuff
}

This is significantly faster than !count(debug_backtrace()), which itself is about twice as fast as my solution involving realpath().

Answer 1

if (!count(debug_backtrace())
{
    // some usefull stuff
}

Answer 2

You probably want one of the "Magic Constants". Depending on what you are trying to do, __FILE__, __FUNCTION__ or __CLASS__ may give you the information you are after.

They are pretty self explanatory:

• __FILE__gives you the current file name
• __FUNCTION__ gives you the name of the current function
• __CLASS__ gives you the name of the current class.

Check the manual for more details

Answer 3

I think I've got it:

if (realpath($_SERVER['SCRIPT_FILENAME']) == __FILE__) {
    // do stuff
}

This caters for the following situations:

1. Web request
2. CLI where PWD is the same as the file's (php file.php)
3. CLI where PWD is explicitly declared (php /path/to/file.php or php ~/path/to/file.php)
4. CLI where PWD is relative to PWD (php ../file.php)

Other things I tried were $_SERVER['SCRIPT_FILENAME'] == __FILE__, which only works for cases 1 and 2; $argv[0] == __FILE__ which only works for case 3; and basename($argv[0])==basename(__FILE__), which is fundamentally flawed as it is entirely possible to have two files called "controller.php" in any given program.

Is there a better way to do this that doesn't use the realpath call and still satisfies all four criteria?