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

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

look at https://www.php.net/manual/en/function.debug-backtrace.php for more details on debug_backtrace function

if ($argv && $argv[0] && realpath($argv[0]) === __FILE__) {
    // ...
}

works like a charm.

when you run php in command line, the name of php file will pass to program as $argv[0] and __FILE__ magic variable mean current file. So we check the running program is current file logically equals Python's __name__ == "__main__".