is_dir in php code example

Example 1: php check if folder exists

<?php
$filename = '/path/to/foo.txt';

if (file_exists($filename)) {
    echo "The file $filename exists";
} else {
    echo "The file $filename does not exist";
}
?>

Example 2: __dir__ in php

<?php
include __DIR__ . "/worker_2.php";