rubygems.rb:8:in `require': no such file to load -- rbconfig (LoadError)

[hasft]

I'm new with ruby. so i uninstall all of the default gems using:

rm -r /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/gems/1.8

and now im stuck to installing rvm, brew, etc..
i get this error when i type gem

/Library/Ruby/Site/1.8/rubygems.rb:8:in `require': no such file to load -- rbconfig (LoadError)
    from /Library/Ruby/Site/1.8/rubygems.rb:8
    from /usr/bin/gem:8:in `require'
    from /usr/bin/gem:8

can someone tell me what i have to do ?

[drbrain]

rbconfig.rb is part of ruby (not rubygems), and you seem to have deleted it.

You need to restore /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/universal-darwin12.0/rbconfig.rb from your backups to use the OS X system ruby again.

Unfortunately this is not a RubyGems bug, so I will close it.