ahadshafiq

echo $PATH
PATH tells Bash where to look to find the executables like "ls" - 
usually , they'll be somwehre like /usr/bin
You need to add those directories to your PATH to make them work. 
path needs to list all the locations where binary files are found 
eg: bin;usr/bin;/usr/local/bin. If you want to change your shell 
then instead of PATH=/usr/bin/ksh you need
Code:
SHELL=/usr/bin/ksh

ahadshafiq

If bundle install gets stuck at  
$ bundle install
Fetching gem metadata from http://rubygems.org/........
Fetching gem metadata from http://rubygems.org/..

then delete the contents of Gemfile.lock
Btw, in vim thats:
If you're in the first line of the file, use dG
If you're anywhere in the file, use :1,$d