Module development and code questions

Helo,

I am trying to port my module to Drupal 5.x.
The problem is, I need this file:

http://api.drupal.org/api/HEAD/file/developer/examples/node_example.module

However this link:

http://api.drupal.org/api/HEAD/file/developer/examples/node_example.modu...

Does anybody know if there is a module which checks if user has previously logged in? I want to make some action when user logs in to the system for the first time (i.e. show welcome message or send an e-mail to admin indicating that user logged in). I know I have to check users table but how to catch login action performed by user?

How would I go about creating a new filter.
I am new to drupal module develpment, but not new to PHP.

Drupal File Comparison Utility Version 1.0
© 2007 Developed by Sam Raheb
Released: January 9, 2007
Designed for all version of Drupal

Download: http://xlecom.com/downloads/Drupal_File_Comparison_Version_1_0.zip

System Requirements
Microsoft Excel 2000, 2002, 2003, or 2007 with Visual Basic for Applications (VBA) support

Instructions

This program provides a means for you visually to keep track of changes you made to any of the original core Drupal files. If a new file is released in the future, you can always compare the changes you made in your modified file and apply the changes to the new core file if needed.

For illustration purposes, this program comes loaded with 3 core modules and 1 CSS file from Drupal version 4.7.5. The changes you see in the Modified File (column D) were changes I made for my particular Drupal website. Column B contains the original code and column D contains the modified code.

To initially get your code or text into the spreadsheet, perform the following steps:

(1) Switch to any of the current spreadsheets and press the "Create a New Sheet" button to create a new sheet.

(2) Switch from Excel to your ASCII text editor and open the original unmodified file you want to transfer to Excel.

(3) Select all the text / code in the file and copy into memory, the clipboard.

I've been looking around quite a bit for a gallery module that would create a folder for each gallery you create plus upload photos into the folder that is related to that gallery. Is there something out there that could help or does anybody have any ideas what I can do to pull that off?
hope that all makes sense...

thanks in advance for any time spent on this.

Shane :)

Is there a way to make a creating an og simpler? I'd like to keep it very brief - just the group name and description, and have the rest of the choices be predetermined. For example, the admin would be picked up from $user->name, and so on. I can write some mid-level PHP, but so far I can't figure out if this is in the module level, a theme issue, or what. I can see how to write to the og db tables with a custom page, but can't see how to get the proper nid to self-generate for the og home page.

Please advise.

Thanks.