screen cheat sheet

screen_cheat_sheet.txt

# screen is useful command as it is included by default on some distributons / operating systemss (eg MacOS). 
# even if you really like tmux, screen is useful in some situations. Both screen and tmux have a good use cases.

# list all screen sessions
screen -list

# start a command in screen 
screen -S my_commands_awesome_name -md bash -lc /usr/bin/path_to_my_awesome_command

# start a command via ssh in screen 
ssh -i .ssh/my_identity_file -p 22 [email protected] "screen -S name_of_session -md bash -lc \"/usr/bin/my_super_command\" && exit"

# execute a set of bash commands (with pipes) in a detached screen
screen -S log_memory_now -dm bash -c '~/bin/my_memory_usage.bash | tee -a /tmp/memory_usage.log'

# create an alias (use funcsave / store in .alias / .bashrc for quick reference
# https://github.com/henri/handy-alias/edit/master/linux_alias.bash
alias log_memory_now_bg "screen -S log_memory_now -dm bash -c '~/bin/my_memory_usage.bash | tee -a /tmp/memory_usage.log'"

# execute multiple commands in a detached screen called "do_it_later"
screen -S do_it_later -dm bash -c "sleep 50; echo do_it_later > /tmp/do_it_later.txt"

# leave screen running after the command compeltes.
screen -dm bash -c 'sleep 50; exec fish'

# name a screen when starting it up
screen -S myasomesession_name 

# start a session in the background with a name
screen -S sleepyhead -dm sleep 60

# start a fish alias in detached screen session and close the session when the process completes.
screen -S my_amazing_session_name -dm fish -c my_super_fish_alias

# kill the sleepyhead session 
screen -S sleepyhead -X quit

# change the name of a screen session 
screen -S origional-name -X sessionname mynew-session-name

# kill detached screen sessions
screen -ls | grep Detached | cut -d. -f1 | awk '{print $1}' | xargs kill

# send a control-c to the myasomesession_name screen session (window 0)
screen -S myasomesession_name -p 0 -X stuff '^C'

# deal with hung processes (first kill the PID, then wipe the screen session) 
# these sometimes show as (Dead ???) if the process has already terminated) in which case you can skip the kill command.
screen -ls # PID at the start of the session name
kill -9 <PID>
screen -wipe <PID>

# clear dead screen sockets - as per the instructions on screen - the following will clear detached screens
screen -wipe

# if you run kill but without -9 then it will typically screen (the parent process) will be notified that child process has 
# been terminated and screen will automatically remove it from the list of sessions (eg - it will tidy up).
kill <PID>

screen_cheat_shortcuts.txt

# this document assumes standard bind key of control-a
# full list : https://manpages.ubuntu.com/manpages/lunar/en/man1/screen.1.html#default%20key%20bindings

# detach from screen
control-a control-d

Some very basic usage of screen.