How can I find an application's base url?

Question

I'd like to find the base url of my application, so I can automatically reference other files in my application tree...

So given a file config.php in the base of my application, if a file in a subdirectory includes it, knows what to prefix a url with.

application/config.php
application/admin/something.php
application/css/style.css

So given that http://www.example.com/application/admin/something.php is accessed, I want it to be able to know that the css file is in $approot/css/style.css. In this case, $approot is "/application" but I'd like it to know if the application is installed elsewhere.

I'm not sure if it's possible, many applications (phpMyAdmin, Squirrelmail I think) have to set a config variable to begin with. It would be more user friendly if it just knew.

Answer 1

Unless you track this yourself, I don't believe this would have a definition. Or rather, you're asking PHP to track something that you're somewhat arbitrarily defining.

The long and short of it is, if I'm understanding your question correctly, I don't believe what you're asking for exists, at least not as "core" PHP; a given framework may provide a "root" URL relative to a directory structure that it understands.

Does that make sense?

Answer 2

The REQUEST_URI combined with dirname() can tell you your current directory, relevant to the URL path:

<?php
  echo  dirname($_SERVER["REQUEST_URI"]);
?>

So http://example.com/test/test.php prints "/test" or http://example.com/ prints "/" which you can use for generating links to refer to other pages relative to the current path.

EDIT: just realized on re-reading that you might be asking about the on-disk path as opposed to the URL path. In that case, you want PHP's getcwd() function instead:

<?php
  echo  getcwd();
?>

Answer 3

Put this in your config.php (which is in your app's root dir):

$approot = substr(dirname(__FILE__),strlen($_SERVER['DOCUMENT_ROOT']));

I think that'll do it.

Answer 4

One solution would be to use relative paths for everything, that way it does not matter where the app is installed. For example, to get to your style sheet, use this:

../css/style.css

Answer 5

If you want the path on the filesystem you can use $_SERVER['DOCUMENT_ROOT']
If you just want the path of the file that appears in the URL after the domain use $_SERVER['REQUEST_URI']

Answer 6

I've never found a way to make it so.

I always end up setting a config variable with the server path to one level above web root. Then it's:

• $configVar . 'public/whatever/' for stuff inside root,
• but you can also include from outside with $configVar . 'phpInc/db.inc.php/' etc.

Answer 7

This works like a charm for me, anywhere I deploy, with or without rewrite rules:

$baseDir = 'http://'.$_SERVER['HTTP_HOST'].(dirname($_SERVER['SCRIPT_NAME']) != '/' ? dirname($_SERVER["SCRIPT_NAME"]).'/' : '/');

Answer 8

I use the following in a homebrew framework... Put this in a file in the root folder of your application and simply include it.

define('ABSPATH', str_replace('\\', '/', dirname(__FILE__)) . '/');

$tempPath1 = explode('/', str_replace('\\', '/', dirname($_SERVER['SCRIPT_FILENAME'])));
$tempPath2 = explode('/', substr(ABSPATH, 0, -1));
$tempPath3 = explode('/', str_replace('\\', '/', dirname($_SERVER['PHP_SELF'])));

for ($i = count($tempPath2); $i < count($tempPath1); $i++)
    array_pop ($tempPath3);

$urladdr = $_SERVER['HTTP_HOST'] . implode('/', $tempPath3);

if ($urladdr{strlen($urladdr) - 1}== '/')
    define('URLADDR', 'http://' . $urladdr);
else
    define('URLADDR', 'http://' . $urladdr . '/');

unset($tempPath1, $tempPath2, $tempPath3, $urladdr);

The above code defines two constants. ABSPATH contains the absolute path to the root of the application (local file system) while URLADDR contains the fully qualified URL of the application. It does work in mod_rewrite situations.