Lack of permissions on sites/default/files I currently manage a Drupal install on a shared university computer (i.e. I don't have root access to the box), but the sites/default/files directory was created with all permissions and ownership set to a unknown user (as is shown below), therefore I have absolutely no way to delete or change anything in this folder without using the Drupal interface or contacting the sysadmin.

I believe the owner of these files is the webserver's user (which is on another box). Is there any way to change the uploaded files permissions/owner within Drupal (or at least delete/chown this folder)?

myself@sparta:~/public_html/drupal/sites/default/files$ ls -la
total 252
drwxrwxr-x 4     48        48   4096 Set  3 11:43 .
dr-xr-xr-x 3 myself  students   4096 Set  2 12:07 ..
-rw-r--r-- 1     48        48 227057 Set  3 11:43 Estatuto.pdf
-rw-rw-r-- 1     48        48     93 Set  2 12:30 .htaccess
drwxr-xr-x 2     48        48   4096 Set  3 11:25 imagefield_thumbs
drwxrwxr-x 2     48        48   4096 Set  3 10:47 languages
-rw-rw-r-- 1     48        48   2666 Set  3 11:25 posse.jpg


Thanks!
You can install the devel module and visit /devel/php on your site. This will give you a place to run ad-hoc PHP from where you could run chown() or something similar on the files in question.

I'm sure it doesn't need to be said but be careful, the last thing you want to do is make a mistake with permissions!