Understanding the Unix file system and ruby installs without Sudo

I'm trying to comprehend the Unix file system on m开发者_C百科y OSX. I'm following wikipedia Filesystem Hierarchy Standard.

I understand when I install ruby gems I must use the command sudo gem install but if I omit sudo, problems may occur.

1. Where are gems installed within the file system when I omit sudo?
2. How can I delete these gems?
3. A Fun side question: When I enter cd ~/.gem my terminal is directed to .gem user$, When I enter cd ~/ and list folders using the ls command I can't find a .gem folder. Where is the .gem folder? How does this fit into the Filesystem?

Ok, looking over the Ruby Gems documentation http://docs.rubygems.org/read/chapter/3

the default install directory is: /usr/local/lib/ruby

Ruby gems uses the environment variable GEM_HOME for the install path. You can change this via the export command like so:

$ export GEM_HOME=/home/mygemrepository $ ruby setup.rb —prefix=/home/mystuff

You can uninstall gems with the gem uninstall command: gem uninstall gemtouninstall

Finally, as I already mentioned files/folders starting with . (such as .bashrc) are hidden from ls by default, so use the ls -a option to see them. You can read more here: http://unixhelp.ed.ac.uk/CGI/man-cgi?ls

Also, sudo is basically saying, "Do this action as if I was the root user," where the root user is essentially like the highest level administrator. It's a common thing to do when installing software via the command line.