PHP file doesn't write to current directory?

Question

I have a PHP file on a web-host that is as follows:

But the file

Answer 1

yes the PHP Doc Says

If filename does not exist, the file is created. Otherwise, the existing file is overwritten, unless the FILE_APPEND flag is set.

That is only if you write have permission on that folder .... try

error_reporting(E_ALL);
ini_set("display_errors", "on");

if (! is_writable(__DIR__)) {
    trigger_error("I don't have permission");
}

file_put_contents('test.txt', 'TEST');