Spiekbriefje voor schermopdrachten

GNU Screen is a terminal multiplexer: it runs several shell sessions inside one terminal, keeps them alive after you disconnect, and lets you reattach later from anywhere.

ℹ️ Every shortcut starts with the prefix, Ctrl+a by default: press the prefix, release it, then press the key. In the tables below Ctrl+a c means “prefix, then c”.

🚀 Sessions from the Shell

# start a session
screen

# start a named session
screen -S <name>

# list running sessions
screen -ls

# reattach to a session
screen -r <name>

# reattach, detaching whoever else is attached
screen -d -r <name>

# reattach if possible, otherwise create the session
screen -R <name>

# attach in parallel with another client (shared screen)
screen -x <name>

# start a detached session running a command
screen -dmS <name> <command>

# run a command inside an existing session
screen -S <name> -X stuff "make test\n"

# quit a session from outside
screen -X -S <name> quit

# clean up dead sessions
screen -wipe

⌨️ Windows

Keys	Action
`Ctrl+a c`	Create a window
`Ctrl+a A`	Rename the current window
`Ctrl+a n`	Next window
`Ctrl+a p`	Previous window
`Ctrl+a Ctrl+a`	Toggle between the last two windows
`Ctrl+a 0…9`	Jump to a window by number
`Ctrl+a "`	Choose a window from a list
`Ctrl+a w`	Show the window bar
`Ctrl+a k`	Kill the current window

🪟 Split Regions

Keys	Action
`Ctrl+a S`	Split into top / bottom regions
`Ctrl+a \|`	Split into left / right regions
`Ctrl+a Tab`	Move the focus to the next region
`Ctrl+a X`	Close the focused region
`Ctrl+a Q`	Close every region except the focused one

💡 A new region starts empty — press Ctrl+a c to open a shell in it, or Ctrl+a " to move an existing window there.

🔌 Session Control

Keys	Action
`Ctrl+a d`	Detach and leave everything running
`Ctrl+a D D`	Detach and log out
`Ctrl+a x`	Lock the terminal (password required)
`Ctrl+a :`	Command prompt (`:quit`, `:sessionname`)
`Ctrl+a ?`	List every key binding
`Ctrl+a \`	Kill every window and quit screen
`Ctrl+a a`	Send a literal `Ctrl+a` (nested screens)

📋 Copy Mode & Scrollback

Keys	Action
`Ctrl+a [`	Enter copy/scrollback mode
`space`	Start the selection, then `space` again to copy
`Ctrl+a ]`	Paste the buffer
`/` and `?`	Search forward / backward
`Ctrl+a >`	Write the buffer to a file
`Esc`	Leave copy mode

📝 Logging & Monitoring

Keys	Action
`Ctrl+a H`	Toggle logging of the window to `screenlog.n`
`Ctrl+a M`	Notify me when this window shows activity
`Ctrl+a _`	Notify me when this window goes quiet
`Ctrl+a C`	Clear the window

# start a session with logging enabled
screen -L -S <name>

# keep 5000 lines of scrollback
screen -h 5000

⚙️ Configuration

Settings live in ~/.screenrc:

# no splash screen, plenty of scrollback
startup_message off
defscrollback 10000

# a status line with the window list and the hostname
hardstatus alwayslastline
hardstatus string '%{= kG}[%H] %{= kw}%?%-Lw%?%{= kR}%n*%f %t%?(%u)%?%{= kw}%?%+Lw%?'

# use Ctrl+z as the prefix instead of Ctrl+a
# escape ^z^z

# turn on mouse-wheel scrolling in the scrollback
termcapinfo xterm* ti@:te@

🧠 Tips

Name your sessions (screen -S deploy) — screen -ls is unreadable once you have three sessions called 12345.pts-0.host.
Over SSH, start work inside screen: the job survives a dropped connection, and screen -d -r picks it back up.
Nested screens (local + remote): press Ctrl+a a to send the prefix through to the inner session.
screen -x attaches several clients to the same session — handy for pair debugging.

📚 Resources

GNU Screen manual
Manual page
Built-in help: Ctrl+a ?