server variable document root is not playing nice with file_exists when virtual folder is involved

Question

I've got a virtual folder on IIS. When I do a server document root, I'm not getting file_exists find the files. But interestingly, if I use include (or require directives for that matter) same files being found.

example

$full_path = $_server['DOCUMENT_ROOT'] . "/file.txt";
include($full_path); // works fine. 
if file_exists($full_path) : // returns false!

Again, this is only when I have a virtual folder involved.

I guess I have to use a different server variable which is not effected by whether there is a virtual folder or not.

eventually, I'd like the following to work

/wwwroot/file.txt should be found with this

file_exists($_server['?'] . "/file.txt")

Answer 1

Use a config file and define baseroot and publicroot.

<?php
// myconfig.php -- stored in the public root
$direx = explode("/", getcwd());
DEFINE ('BASEROOT', '/'.$direx[1].'/'.$direx[2].'/'); // host/mysite/
DEFINE ('PUBLICROOT', '/'.$direx[1].'/'.$direx[2].'/'.$direx[3].'/'); // host/mysite/public_html/
?>

<?php
require_once('myconfig.php'); // called on every page

IF (File_Exists(PUBLICROOT.'some_folder/file.txt')) { /* do something */ }

include_once(PUBLICROOT.'some_folder/file.txt');
?>

Answer 2

I don't know how IIS virtual folders behave, but you get the current scripts full file path from a global constant __FILE__, see at http://php.net/manual/en/language.constants.predefined.php.

If you know the relative path from your script, use something like this:

$filepath = dirname(__FILE__) . "/../../file.txt";

Not sure if this solves your problem though.