How to screw up then fix Gnome in Ubuntu!

Yesterday I read about a supposedly nice-looking patched version of Nautilus and decided to try it out. I installed it, used it for a few hours before bed, and realized that I really hadn't gained anything special by installing it.

When I uninstalled it this morning, I really screwed up my installation of gnome. So much so that I simply couldn't log into ubuntu using the Gnome Display Manager (the meat and bones of the Ubuntu Grahpical User Interface). Thankfully, I still had access to the Virtual Console by pressing Control+Alt+F2 at the login screen.

One thing I learned is that I still don't know how to initialize an ethernet connection to my router/DSL modem to give me an internet connection from the command line. I know that you can set your ethernet interface's IP address by typing in sudo ifconfig eth0 address and you can substitute address with netmask address to change the netmask (I think it's usually 255.255.255.0 on most consumer routers). That didn't work for me however. I also tried toying with the route command, but I really didn't understand how to work with that.

What ended up saving me was a suggestion that I read on ubuntuforums.org, in response to someone in a similar situation, that they should download an alternative ubuntu installation iso, burn it to CD and use it as a source for package updates. I didn't end up burning it to CD. Rather, I did the following:

1. downloaded it to my USB stick
2. mounted the ISO in a newly made separate directory directory (using the command sudo mount -o loop ubuntu-9.10-alternate-i386.iso /media/testing)
3. navigated to that directory (cd /media/testing)
4. switched bash into root mode (sudo bash -i)
5. Finally I initialized an upgrade from the mounted Alternative Install ISO (./cdromupgrade)

The alternative install ISO fixed my broken GNOME/Nautilus packages, restarted my computer and .... VOILA! Everything was back to normal! Nothing was lost and I'm now a happy camper.

I'm definitely going to keep an alternative install ISO on me and probably also a regular install ISO too. After-all, they are free tools that don't even need to be burned to CD.