Rails commands only work on one terminal

问题

I installed Ruby and then RVM, and then configured Rails.

It all works when I call it from the original terminal. But when I try to call various commands from new terminals, the system just gives an error message such as this one:

$rails server
The program 'rails' is currently not installed.  You can install it by typing:
sudo apt-get install rails

Why does that happen? Is there some global variable which needs to be set? I am using Ubuntu by the way.

回答1:

Example of how/where gems are installed:

rvm use 1.8.7
ruby -v           # 1.8.7 returned
rvm gemdir        # some directory returned 
gem install rails # (installed to the directory returned by `rvm gemdir` in 1.8.7)
rails -v          # some version returned 

rvm use 1.9.2
ruby -v           # 1.9.2 returned
rvm gemdir        # some directory returned 
rails -v          # Error if not installed, else version is shown
gem install rails # (installed to the directory returned by `rvm gemdir` in 1.9.2)
rails -v          # some version returned

Now, the Rails gem is now installed in 2 directories (1 for each of the Ruby versions)

Now in order to set a default version of Ruby (instead of typing rvm use every time you open a terminal), you can run:

rvm use 1.9.2 --default

See the documentation for more information about default.

Some other commands:

Default ruby rvm list default
All Rubies: rvm list

Also note do not use sudo with RVM!

Hope that clears things up!

回答2:

It's also important to note that gnome terminal needs to have access to the login shell. This can be configured on Ubuntu 12.04 by right-clicking on your terminal pane, clicking Profiles > Profile Preferences selecting the Title and Command pane and toggling the option Run command as login shell.

Source: RVM + Gnome Terminal