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Screen Cheatsheet ​

Overview ​

GNU Screen is a terminal multiplexer that allows you to run multiple terminal sessions within a single terminal window. It enables session persistence, detachment, and reattachment, making it ideal for remote work and long-running processes.

Installation ​

Package Managers ​

bash
# Ubuntu/Debian
sudo apt install screen

# macOS
brew install screen

# CentOS/RHEL
sudo yum install screen

# Arch Linux
sudo pacman -S screen

# From source
wget https://ftp.gnu.org/gnu/screen/screen-4.9.0.tar.gz
tar -xzf screen-4.9.0.tar.gz
cd screen-4.9.0 && ./configure && make && sudo make install

Basic Usage ​

Starting Screen ​

bash
# Start new screen session
screen

# Start named session
screen -S sessionname

# Start session with command
screen -S mysession htop

# Start detached session
screen -d -m -S mysession

# Start session with specific shell
screen -S mysession bash

Session Management ​

bash
# List sessions
screen -ls
screen -list

# Attach to session
screen -r sessionname
screen -r 12345  # Using session ID

# Attach to session (force if attached elsewhere)
screen -d -r sessionname

# Detach from session
# Inside screen: Ctrl+a d

# Kill session
screen -S sessionname -X quit

# Kill all sessions
pkill screen

Key Bindings (Default Prefix: Ctrl+a) ​

Session Commands ​

Ctrl+a d    # Detach from session
Ctrl+a D D  # Detach and logout
Ctrl+a \    # Kill all windows and terminate
Ctrl+a :    # Enter command mode

Window Commands ​

Ctrl+a c    # Create new window
Ctrl+a n    # Next window
Ctrl+a p    # Previous window
Ctrl+a 0-9  # Switch to window by number
Ctrl+a "    # List windows
Ctrl+a w    # Show window list
Ctrl+a k    # Kill current window
Ctrl+a A    # Rename current window
Ctrl+a '    # Prompt for window number to switch to

Window Navigation ​

Ctrl+a Ctrl+a  # Switch to last window
Ctrl+a l       # Refresh screen
Ctrl+a L       # Toggle login state
Ctrl+a M       # Monitor window for activity
Ctrl+a _       # Monitor window for silence

Split Screen (Regions) ​

Ctrl+a S    # Split horizontally
Ctrl+a |    # Split vertically (if supported)
Ctrl+a Tab  # Switch between regions
Ctrl+a Q    # Close all regions except current
Ctrl+a X    # Close current region

Copy Mode ​

Ctrl+a [    # Enter copy mode
Ctrl+a ]    # Paste buffer
Ctrl+a >    # Write buffer to file
Ctrl+a <    # Read buffer from file

Copy Mode Navigation ​

Enter Copy Mode ​

Ctrl+a [    # Enter copy mode
Ctrl+a Esc  # Enter copy mode (alternative)

Movement in Copy Mode ​

h, j, k, l  # Move cursor (vi-style)
Arrow keys  # Move cursor
w           # Next word
b           # Previous word
0           # Beginning of line
$           # End of line
g           # Go to beginning of buffer
G           # Go to end of buffer
Ctrl+f      # Page down
Ctrl+b      # Page up
/           # Search forward
?           # Search backward
n           # Next search result
N           # Previous search result

Selection and Copy ​

Space       # Start/end selection
Enter       # Copy selection and exit copy mode
Esc         # Exit copy mode

Configuration ​

Configuration File (~/.screenrc) ​

bash
# Basic settings
startup_message off
defscrollback 10000
hardstatus alwayslastline
hardstatus string '%{= kG}[ %{G}%H %{g}][%= %{=kw}%?%-Lw%?%{r}(%{W}%n*%f%t%?(%u)%?%{r})%{w}%?%+Lw%?%?%= %{g}][%{B}%Y-%m-%d %{W}%c %{g}]'

# Set default shell
shell -$SHELL

# Enable 256 colors
term screen-256color

# Mouse support (if available)
mousetrack on

# Automatically detach on hangup
autodetach on

# Change escape key
escape ^Aa  # Default is Ctrl+a

# Window numbering
bind c screen 1
bind ^c screen 1
bind 0 select 10
screen 1

# Split screen bindings
bind | split -v
bind - split
bind + resize +5
bind = resize =
bind _ resize -5

# Window navigation
bind j focus down
bind k focus up
bind h focus left
bind l focus right

# Reload config
bind r source ~/.screenrc

# Logging
bind L log

# Monitor activity
bind m monitor
bind M monitor

Advanced Configuration ​

bash
# Status line customization
hardstatus on
hardstatus alwayslastline
hardstatus string "%{.bW}%-w%{.rW}%n %t%{-}%+w %=%{..G} %H %{..Y} %m/%d %C%a "

# Window titles
shelltitle "$ |bash"

# Startup windows
screen -t "editor" 1 vim
screen -t "server" 2
screen -t "logs" 3 tail -f /var/log/messages

# Key bindings for common tasks
bind ^k kill
bind k kill
bind ^\ quit
bind \\ quit
bind ^h hardcopy
bind h hardcopy

# Scrollback buffer
defscrollback 10000

# Visual bell
vbell on
vbell_msg "   Wuff  ----  Wuff!!  "

# Activity monitoring
activity "Activity in %t(%n)"

# Silence monitoring
silence on
silencewait 15

# Automatic window naming
shelltitle '$ |bash'

# Password protection
password ODSJQf.4IJN7E    # Encrypted password

# Multiuser mode
multiuser on
acladd user1,user2

Advanced Features ​

Multiple Users ​

bash
# Enable multiuser mode
screen -S shared
# In screen: Ctrl+a :multiuser on
# In screen: Ctrl+a :acladd username

# Other user connects
screen -x username/shared

Session Sharing ​

bash
# Start shared session
screen -S shared

# Allow others to attach
# In screen: Ctrl+a :multiuser on
# In screen: Ctrl+a :acladd otheruser

# Other user attaches
screen -x shared

Logging ​

bash
# Enable logging for window
# In screen: Ctrl+a H

# Log to specific file
# In .screenrc:
logfile /tmp/screen-%t.log

# Automatic logging
deflog on

Monitoring ​

bash
# Monitor window for activity
Ctrl+a M

# Monitor for silence
Ctrl+a _

# Set silence timeout (seconds)
# In .screenrc:
silencewait 30

Command Line Options ​

Session Management ​

bash
# Create detached session
screen -d -m -S mysession

# Create session and run command
screen -d -m -S mysession bash -c 'cd /var/log && tail -f messages'

# Send command to session
screen -S mysession -X stuff 'ls -la\n'

# Send command to specific window
screen -S mysession -p 0 -X stuff 'htop\n'

# Capture window content
screen -S mysession -p 0 -X hardcopy /tmp/screen.dump

Window Management ​

bash
# Create window with title
screen -S mysession -X screen -t "editor" vim

# Kill specific window
screen -S mysession -p 1 -X kill

# List windows
screen -S mysession -Q windows

Scripting ​

Automation Scripts ​

bash
#!/bin/bash
# dev-setup.sh

SESSION="development"

# Check if session exists
if ! screen -list | grep -q "$SESSION"; then
    # Create new session
    screen -d -m -S "$SESSION"
    
    # Setup windows
    screen -S "$SESSION" -X screen -t "editor" 1 vim
    screen -S "$SESSION" -X screen -t "server" 2
    screen -S "$SESSION" -X screen -t "logs" 3 tail -f /var/log/messages
    
    # Send commands to windows
    screen -S "$SESSION" -p 2 -X stuff 'cd ~/project && npm start\n'
    
    # Select first window
    screen -S "$SESSION" -X select 1
fi

# Attach to session
screen -r "$SESSION"

Batch Operations ​

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

# Send command to all windows
for i in {0..9}; do
    screen -S mysession -p $i -X stuff 'echo "Hello from window $i"\n'
done

# Create multiple sessions
for name in web api db; do
    screen -d -m -S "$name"
done

Integration ​

With SSH ​

bash
# Auto-start screen on SSH login
# Add to ~/.bashrc on remote server
if [ -z "$STY" ] && [ -n "$SSH_CONNECTION" ]; then
    screen -RR ssh_session
fi

# Or use a function
ssh_screen() {
    ssh -t "$1" 'screen -RR'
}

With System Services ​

bash
# Run service in screen
screen -d -m -S myservice /path/to/service

# Systemd service file
[Unit]
Description=My Service in Screen
After=network.target

[Service]
Type=forking
User=myuser
ExecStart=/usr/bin/screen -d -m -S myservice /path/to/service
ExecStop=/usr/bin/screen -S myservice -X quit

[Install]
WantedBy=multi-user.target

Comparison with tmux ​

Screen vs tmux ​

Screen:
+ Older, more stable
+ Simpler configuration
+ Better for basic use cases
+ Lower resource usage
- Less active development
- Fewer features
- Limited pane support

tmux:
+ More active development
+ Better pane management
+ More features
+ Better scripting support
- Steeper learning curve
- More complex configuration

Tips and Tricks ​

Productivity Tips ​

bash
# Quick session switching
alias s='screen -ls'
alias sr='screen -r'
alias sn='screen -S'

# Function to create or attach
sc() {
    if [ $# -eq 0 ]; then
        screen -ls
    else
        screen -r "$1" || screen -S "$1"
    fi
}

# Nested screen sessions
# Change escape key for inner session
# In .screenrc: escape ^Bb

Useful Aliases ​

bash
# Add to ~/.bashrc
alias sl='screen -ls'
alias sr='screen -r'
alias ss='screen -S'
alias sk='screen -X -S'

# Function for easy session management
screen_session() {
    case "$1" in
        ls|list)
            screen -ls
            ;;
        new)
            screen -S "$2"
            ;;
        attach)
            screen -r "$2"
            ;;
        kill)
            screen -S "$2" -X quit
            ;;
        *)
            echo "Usage: screen_session {ls|new|attach|kill} [session_name]"
            ;;
    esac
}

Troubleshooting ​

Common Issues ​

bash
# Fix "Cannot open your terminal '/dev/pts/0'" error
script /dev/null

# Or use:
screen -x

# Dead session cleanup
screen -wipe

# Permission issues
chmod 755 /var/run/screen

# Check screen version
screen -v

# Debug mode
screen -d -m -L -S debug command

Recovery ​

bash
# Recover dead sessions
screen -D -R

# Force detach and reattach
screen -d sessionname
screen -r sessionname

# Clean up dead sessions
screen -wipe

Security ​

Access Control ​

bash
# Set password protection
# In .screenrc:
password your_encrypted_password

# Generate encrypted password
screen -X password

# Multiuser access control
multiuser on
acladd username
aclchg username +rwx "#"

Best Practices ​

bash
# Use named sessions
screen -S descriptive_name

# Regular cleanup
screen -wipe

# Monitor session activity
# In .screenrc:
activity "Activity in %t(%n)"

# Limit scrollback buffer
defscrollback 1000

Resources ​

  • Official Documentation: gnu.org/software/screen
  • Manual: man screen
  • Info: info screen
  • Examples: /usr/share/doc/screen/examples/