Frequently-appearing phrases which relate to paths.

paths.php

<?php
// Frequently-appearing phrases which relate to paths.
$paths = array(
  array('__FILE__', __FILE__),
  array('realpath(__FILE__)', realpath(__FILE__)),
  array('dirname(__FILE__)', dirname(__FILE__)),
  array('basename(__FILE__)', basename(__FILE__)),
  array('pathinfo(__FILE__)', pathinfo(__FILE__)),
  array('__DIR__', __DIR__),
);

foreach ($paths as $row) {
    echo "{$row[0]}:\t";

    if (is_array($row[1])) {
        print_r($row[1]);
    } else {
        echo "{$row[1]}\n";
    }
}

If you put this script in C:\work\htdocs\sandbox\paths.php, for example, the result is following:

$ cd c:\work\htdocs\sandbox
$ php paths.php
__FILE__:       C:\work\htdocs\sandbox\paths.php
realpath(__FILE__):     C:\work\htdocs\sandbox\paths.php
dirname(__FILE__):      C:\work\htdocs\sandbox
basename(__FILE__):     paths.php
pathinfo(__FILE__):     Array
(
    [dirname] => C:\work\htdocs\sandbox
    [basename] => paths.php
    [extension] => php
    [filename] => paths
)
__DIR__:        C:\work\htdocs\sandbox