Use screen to prevent "Broken Pipe" messages and terminal session timeouts

Why?

When connecting to our systems (head, headnode7, lmm, etc.) via PuTTY, or terminal in mac when there is a disruption in the ssh connection, you will see a "Broken Pipe" error and loose access to any programs that were running, without being able to recover them. Screen and tmux allow you to "detatch" a session (i.e. keep it running in the background), and move on to another task in the same terminal window, or disconnect from the machine. 

Basic Linux Screen Usage

1. After connecting to a machine from PuTTY, terminal, etc., type

   Code Block
   language bash
   screen

2. Run the desired program
3. Use the key sequence Ctrl-a + Ctrl-d to detach from the screen session, this will keep it running in the background

4. To see a list of active screen sessions, type

   Code Block
   language bash
   screen -ls

5. Reattach to the screen session by typing

   Code Block
   language bash
   screen -r [your session id here]

There are many useful tutorials for using screen to preserve terminal sessions, here is one: https://linuxize.com/post/how-to-use-linux-screen/#starting-linux-screen

Basic tmux usage

1. After connecting to a machine from PuTTY, terminal, etc., type 

   Code Block
   language bash
   tmux

2. Run the desired program
3. Use the key sequence Ctrl+b d to detatch the session

4. To see a list of active tmux sessions

   Code Block
   tmux -ls

5. To reattach a tmux  session type

   Code Block
   language bash
   tmux attach-session -t [your session id here]

...