Screen is a window manager for text terminals. It's very useful for managing your virtual environment, particularly when you are teaching with other instructors.
Ansible installed a .screenrc configuration file onto your server and we'll assume that you are using the NSRC's custom screen configuration for these exercises.
You'll start a screen session from the command line. It's good practice to check what sessions are currently running on your server before starting a new one.
Ssh to your server:
$ ssh nsrc@s1.ws.nsrc.orgList any existing screen sessions:
$ screen -lsThere shouldn't be any screen sessions.
Now that you've confirmed that there are no sessions, create a new screen session named workshopX (e.g. workshop1, workshop2, workshop3). Agree with your partners what you will name your sessions. Each person should pick a unique session name in your group.
$ screen -S workshopX You should see the status bar at the bottom of your screen with 3 windows named shell1, shell2, and shell3. You can also list your session and those of your partners with:
$ screen -lsYou have 3 windows in your session. Let's create a new window. Type C-x C-c to create the new window. It will be named bash.
Let's give it a more useful name. Type C-x A (this is case-sensitive) and you'll see the following prompt at the bottom of your screen:
Set window's title to:
Delete bash and name your new window compile. The status bar at the bottom of your screen will be updated when you hit return.
Now navigate to a new window with C-x n. You can return to the previous window with C-x p.
Next navigate to the window labeled "shell2" and kill it with C-x k. Then type y to confirm that you want to kill the current window.
Let's start a program that will update continously:
$ watch --interval 1 dateFinally detach from your session with C-x d.
Now you will connect to one of your partner's screen sessions. You should be at the command line and not in a screen session. If your partner created a session named workshop2, you would use
$ screen -r -d workshop2Navigate through the windows until you find the one running the watch --interval 1 date command. Kill the process by typing C-c and then detach from your partner's session with C-x d.
C == Control
Screen's default command sequence is C-a. We've redefined this as C-x because C-a is used by other programs, most importantly bash command line editing.
C-x C-c new window
C-x A name window
C-x k kill window
C-x d detach from session
C-x n,p next or previous window
C-x 1,2,3 move to specific window
C-x ESC enter scrollback mode