Module development and code questions

I'm developing a new node type which needs to have a file attachment. I would just require upload.module and be done with it, except that the RSS feed's enclosure tag needs to have some extra data-- things like an MD5 hash of the file, with a custom attribute name-- for use by a custom feed reader.

Since the RSS feed will probably get lots of traffic, the MD5 hash and other info really needs to be calculated when the node is created. However I don't know how I can get a reference to the file to do this, or how to inject the data into upload.module's enclosure tag.

I'm having problems setting a cookie in a custom module: the cookie just doesn't get created.

I am using setcookie($name, $value, 0) in a function which is called by hook_nodeapi.

Is there something I am missing?
Thanks
FnL

I created a new content type with the CCK module and manage the access permissions through roles and users. So far it looks OK. An anonymous user can only view the content, an administrator and member can view and edit the content.
In our case an administrator is allowed to update and delete the node, but a member should only be granted to view and update a node.

Is there an easy way to remove or disable the delete button?

Many Thanks,
Chris

Here's a simple question:

I downloaded the pathauto module (pathauto-5.x-1.2) and placed it into /modules, ran the upgrade script ... and it's not appearing as a module in Administer modules.

I'm running Drupal 5.1.

Is there any way to find out if Pathauto conflicts with other modules?

-Jay

Because the concept of "Friend of a Friend" (FOAF) is so important in Social Networking, I'm trying to achieve a special kind of dinamic display for each end-user, and I was wondering if any of you seen a module that can help me achieve this. This is what I want to achieve:

Each end-user will be able to see his "Friends'" (i.e. users with whom he has a two-way connection in Buddylist), avatars framed in green border, and names displayed in green (or maybe some other distinct way).

I'm pretty new to drupal and am developing a news site with categories, subcategories, and articles contained within the subcategories. I'm using pathauto for automatic permalink generation when I post into a subcategory.