A module, Take_Control is now available for Drupal 6.x which you can use to change permissions of your files/folders on the server.

Warning: You cannot undo the file permissions that are changed by the script below. Proceed with extreme caution.

Symptom:

• "Permission Denied" When trying to work with your site over FTP.
• You cannot modify directories inside the /files folder that were created by Drupal.

Solution:

• Tell Apache to give you back control of your files.

One side effect of having files created by Drupal (eg the image module), is that your user account might not have ownership of them any more. And you might not be able to delete the or move them around.

There is a workaround though. You can create a small PHP script containing the commands you want to carry out and upload it to the server. Once uploaded, you can run it from your web browser by entering the URL for it. The script will run as the user account the webserver runs as. Be sure to remove the script after you have used it though.

simple case:

Use a drupal PHP-format page (eg just a php code snippet) to run

`chmod -R a+w sites/default/files`;

and you (and the rest of the neighborhood!) should have write access so you can write/delete anything in your files and images directory via shell/FTP again. Modify the command as needed.

If that doesn't work, and particularly if you are trying to uninstall Drupal and want to be able to erase all files, save the following snippet as a php file (e.g. fix.php). It will try to make all directories and files writable in a recursive fashion. If you put this in the root folder of your Drupal installation and run it by going to http://www.example.com/fix.php it should operate on all possible files within your Drupal site. If you put it in your files directory, it will operate there, e.g: http://www.example.com/sites/default/files/fix.php

Important: this code should only be used if you remember to delete it immediately after use. As above, its use may put your site into an insecure state.

file_fix_directory(dirname(__FILE__));

function file_fix_directory($dir, $nomask = array('.', '..')) {
  if (is_dir($dir)) {
     // Try to make each directory world writable.
     if (@chmod($dir, 0777)) {
       echo "<p>Made writable: " . $dir . "</p>";
     }
  }
  if (is_dir($dir) && $handle = opendir($dir)) {
    while (false !== ($file = readdir($handle))) {
      if (!in_array($file, $nomask) && $file[0] != '.') {
        if (is_dir("$dir/$file")) {
          // Recurse into subdirectories
          file_fix_directory("$dir/$file", $nomask);
        }
        else {
          $filename = "$dir/$file";
            // Try to make each file world writable.
            if (@chmod($filename, 0666)) {
              echo "<p>Made writable: " . $filename . "</p>";
            }
        }
      }
    }

    closedir($handle);
  }

}

Documentation for PHP filesystem functions:
http://php.net/manual/ref.filesystem.php

And documentation for the PHP system() function:
http://php.net/manual/function.system.php

With these techniques you should be able to get the webserver to do anything the Unix shell can do. Some hosts however limit your ability to use shell-level commands like this, in which case you must approach them to ask for the appropriate fix.

Take care doing this though. These are the kind of tasks where it pays to practice them on your test instance first - you do have a test instance right?