Wrote /home/j2112/Ruby/j21OO_intro.rb (No changes need to be saved) command-execute: Buffer is read-only: #<buffer j21OO_intro.rb<2>> [3 times] g is undefined [3 times] Quit Beginning of buffer scroll-signal-boundary-error: Beginning of buffer Wrote /home/j2112/Ruby/*Messages* Saving file /home/j2112/Ruby/*Messages*...