[wp-hackers] Bad assumption on creation of ABSPATH

Chris gaarai at gaarai.com
Thu Nov 13 17:32:33 GMT 2008

If you look at any of the high-level files of WordPress that handle 
setting up the environment for WP, you'll find the following:

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

Does it bother anyone else that all the ABSPATH defines presume to 
always add a '/' as the directory delimiter?

It took me a while to realize that this simple thing was the source of 
so many of my woes. For example, consider the following code:

$this->_pluginPath = dirname( __FILE__ );
$this->_pluginRelativePath = str_replace( ABSPATH, '', $this->_pluginPath );
$this->_pluginURL = get_option( 'home' ) . '/' . $this->_pluginRelativePath;

This code should be a simple and straight-forward way for me to always 
have access to the paths and URL bases that I need when developing 
plugins, but it will fail horribly when run on Windows. The source? This 

str_replace( ABSPATH, '', $this->_pluginPath );

Imagine this running on Windows:

str_replace( "C:\xampp\htdocs\wordpress/", '', "C:\xampp\htdocs\wordpress\wp-content\plugins\my-plugin" );

Now I have a URL base of 
which is not at all what I was wanting.

The fix that I've been employing is as follows:

$this->_pluginRelativePath = ltrim( str_replace( rtrim( ABSPATH, '\\\/' ), '', $this->_pluginPath ), '\\\/' );
$this->_pluginURL = get_option( 'home' ) . '/' . $this->_pluginRelativePath;

Quite frankly, I find this to be unacceptable. Not only does it leave me 
with a sloppy relative path by having a forward slash in the middle of a 
backslash delimited path, but it also requires way too much work to 
derive. I think most people would agree that my original code is much 
more understandable and solid.

Basically, I find a number of issues created by simply placing a forward 
slash at the end of the ABSPATH:

    * Makes being compatible with Windows hosts that much harder.
    * Puts unnecessary burden on plugin and theme developers. I'm sure
      that we can all agree that making things easier for theme and
      plugin developers is good for everyone.

People may argue that I can simply use the numerous defines to construct 
my needed paths and url bases, but that would have its own problems:

    * If I rely on the defines, then my code suddenly has dependency
      issues and can break depending on what version of WP it is running on.
    * The beauty of my original code is that it is highly adaptable. No
      matter what type of folder structure, file migration, or
      file/directory renaming they do, the code will always know where
      it is and what URL will point to it. If I use defines and my
      plugin's name for generating a path and the user renames my plugin
      or puts it in a different folder, my code breaks. Sure, I can
      insulate against that by doing a lot of logic code, but that is a
      lot of work to do just to make sure that I have the right path.

Sorry for my verbosity, I just wanted to make it clear that a seemingly 
simple thing can create a large array of issues.

I really should have brought this up before as a fix may have been put 
in place for 2.7. Oh well... Here's hoping for a fix in the next release.

- Chris Jean

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