Screen

Getting Started

Start using screen and learn basic concepts

Installation and Basics

Install screen and understand what it does

Install Screen on Linux

Installs GNU Screen terminal multiplexer and verifies the installation.

Code

# On Debian/Ubuntu
sudo apt-get install screen

# On RedHat/CentOS/Fedora
sudo yum install screen

# On macOS with Homebrew
brew install screen

# Verify installation
screen --version

Execution

screen --version

Output

Screen version 4.09.00 (GNU) 23-Oct-22

Most Linux distributions include screen by default
Screen is lightweight and available on almost all Unix-like systems
No special permissions required to run screen

Start Screen without a session name

Launches Screen and shows running sessions.

Code

# Start a basic screen session
screen

# Start screen with UTF-8 support
screen -U

# Start and list existing sessions
screen -ls

Execution

screen -ls

Output

There is a screen on:
  12345.pts-0.myhost  (Attached)

Creates a numbered session (starts from 0)
-U flag enables UTF-8 character support
Attached status indicates active session

Understanding Screen Concepts

Learn the hierarchical structure of screen

Understanding screen session and window hierarchy

Screen organizes your work into sessions containing multiple numbered windows.

Code

1
Session (development)
2
├── Window 0 (shell)
3
├── Window 1 (editor)
4
├── Window 2 (build)
5
└── Window 3 (testing)

Execution

screen -ls development

Output

There are screens on:
  12345.development  (Attached)

One session can contain many windows (like terminal tabs)
Unlike tmux, screen does not have panes (but can split horizontally)
Each window maintains its own shell environment and history

Check current screen setup

View information about your current screen session and windows.

Code

# Inside screen session - show info
Ctrl+A i

# List all windows in current session
Ctrl+A w

# Show current window number
Ctrl+A N

Execution

screen -version && echo 'Screen ready'

Output

Screen version 4.09.00 && Screen ready

Ctrl+A is the default command prefix in screen
Window list shows all open windows with their numbers and names
Most operations inside screen use Ctrl+A prefix

Creating Your First Session

Create and manage your first screen session

Create a named screen session

Creates a named screen session (with -S) that's easier to remember and reattach to.

Code

# Create a new named session
screen -S mywork

# Create session and execute command
screen -S development -d -m "bash -c 'echo Starting development'"

# Create session in detached mode
screen -S build -d

Execution

screen -S test -d

Output

[screen created]

-S flag specifies the session name
-d flag starts session detached (in background)
-m flag allows starting with a command
Named sessions are much better than numbered ones

Attach to a session

List all sessions and attach to the one you want to work with.

Code

# List all available sessions
screen -ls

# Attach to a specific session
screen -r mywork

# Attach if already attached, multi-display
screen -x mywork

# Force reattach if needed
screen -r -d mywork

Execution

screen -ls

Output

There are screens on:
  12345.mywork    (Detached)
  12346.development  (Attached)

-r attaches to a detached session
-x allows multiple users to view same session
-d flag forces detach of other connections

Session Management

Work with multiple screen sessions

Create and Attach Sessions

Create new sessions and attach to existing ones

Create multiple independent sessions

Create multiple independent screen sessions for different projects or tasks.

Code

# Create session for development
screen -S dev -d

# Create session for servers
screen -S servers -d

# Create session for testing
screen -S test -d

# List all created sessions
screen -ls

Execution

screen -S workspace -d && screen -ls

Output

There is a screen on:
  99999.workspace  (Detached)

Each session is completely independent
Sessions continue running even if you disconnect
Great for long-running processes and server management

Attach and detach from sessions

Attach to your most recent session and navigate between windows.

Code

# Attach to an existing session
screen -r dev

# Inside screen, detach with:
# Ctrl+A d (press Ctrl+A, release, then press D)

# Switch between windows in a session
# Ctrl+A [0-9] to jump to window number
# Ctrl+A n for next window
# Ctrl+A p for previous window

Execution

screen -r

Output

[attached to session]

Detaching preserves your session - everything keeps running
Ctrl+A is the command prefix for all screen operations
You can reattach to any detached session later

List and Monitor Sessions

View and manage all running sessions

List all screen sessions with details

View all running screen sessions and their attachment status.

Code

# List all active sessions
screen -ls

# Get more detailed session info
screen -ls | grep -E '^\s+[0-9]'

# Check a specific session
screen -ls mywork

# List with additional stats
ps aux | grep SCREEN

Execution

screen -ls

Output

There are screens on:
  12345.dev    (Attached)
  12346.servers    (Detached)
  12347.testing    (Detached)
3 Sockets in /run/screen/S-user.

Attached means session is currently being viewed in a terminal
Detached sessions continue running in the background
Shows number of sockets (connection points) to session

Monitor and manage session processes

Monitor active processes and send commands to sessions remotely.

Code

# Inside screen - show window list info
Ctrl+A w

# Show last 30 lines activity
Ctrl+A g

# Display current screen size
echo $LINES x $COLUMNS

# Kill a session from outside
screen -S mywork -X quit

# Send command to detached session
screen -S mywork -X send-keys "ls -la" Enter

Execution

screen -S worker -X send-keys "echo hello" Enter

Output

hello

-X allows sending commands to sessions without attaching
send-keys can execute commands in detached sessions
Very useful for automation and monitoring

Kill and Destroy Sessions

Terminate sessions and clean up resources

Properly terminate screen sessions

Terminate screen sessions cleanly or forcefully when needed.

Code

# Kill session from outside
screen -S mywork -X quit

# Inside screen, exit shell to kill session
exit

# Inside screen, use Ctrl+A k to kill current window
Ctrl+A k

# Force kill a stuck session
kill -9 $(pgrep -f 'SCREEN.*mywork')

# Clean up all dead sessions
screen -wipe

Execution

screen -S temp -d && screen -S temp -X quit && screen -ls

Output

No Sockets found.

exit command closes shell and kills session gracefully
Ctrl+A k kills only current window, not entire session
-X quit is cleanest remote termination method
kill -9 should be last resort for stuck sessions

Handle zombie and dead sessions

Clean up dead or orphaned screen sessions.

Code

# List sessions including dead ones
screen -ls

# Remove dead sessions
screen -wipe

# Clear out orphaned screen processes
killall -v screen

# Verify cleanup
screen -ls

Execution

screen -wipe

Output

[dead sessions removed]

Dead sessions occur when session crashes or terminal closes abruptly
screen -wipe removes dead sessions automatically
Only use killall screen if absolutely necessary

Window Management

Create and navigate multiple windows within a session

Create and Switch Windows

Create new windows and navigate between them

Create new windows in a session

Create multiple windows within a screen session for different tasks.

Code

# Inside screen - create new window
Ctrl+A c

# Create window with a specific shell command
Ctrl+A :screen -t "editor" vim

# Create window and name it
Ctrl+A :title editor

# Create numbered window sequence
for i in {1..5}; do
  screen -S dev -X new-window -t dev:$i
done

Execution

echo "Use Ctrl+A c inside screen to create windows"

Output

Use Ctrl+A c inside screen to create windows

Each window is independent with its own shell
Window numbering starts at 0 by default
Windows can have friendly names for easy identification
-t flag specifies window title during creation

Switch between windows efficiently

Navigate quickly between windows using keyboard shortcuts.

Code

# Jump to window by number (0-9)
Ctrl+A 0  # Jump to window 0
Ctrl+A 1  # Jump to window 1
Ctrl+A 2  # Jump to window 2

# Move to next/previous window
Ctrl+A n  # Next window
Ctrl+A p  # Previous window

# Switch to last active window
Ctrl+A Ctrl+A

# List all windows
Ctrl+A w

Execution

echo "Inside screen session use Ctrl+A w to see all windows"

Output

Inside screen session use Ctrl+A w to see all windows

Ctrl+A w shows visual list of all windows
Ctrl+A Ctrl+A toggles between last two windows
Direct number access (Ctrl+A 0-9) is fastest for frequent windows

Manage and Close Windows

Rename, close, and organize windows

Rename and manage windows

Rename windows to organize and identify them clearly.

Code

# Rename current window (inside screen)
Ctrl+A A

# Change window title in command mode
Ctrl+A :title newname

# Rename from shell (outside screen)
screen -S mywork -p number -X title newname

# Move window to different position
Ctrl+A :number position

Execution

echo "Press Ctrl+A A inside screen to rename current window"

Output

Press Ctrl+A A inside screen to rename current window

Ctrl+A A opens rename prompt in current window
window names help identify purpose at a glance
Can set window titles programmatically

Close windows and manage cleanup

Close and remove windows when no longer needed.

Code

# Kill current window (inside screen)
Ctrl+A k

# Close window with confirmation
Ctrl+A K

# Exit shell in window (closes window)
exit

# Remove specific window from shell
screen -S mywork -p 2 -X kill

# List and close all windows except current
Ctrl+A :killall

Execution

echo "Use Ctrl+A k to kill current window"

Output

Use Ctrl+A k to kill current window

Ctrl+A k kills window immediately
Ctrl+A K asks for confirmation before killing
exit command also closes the window gracefully

Window Navigation Tips

Advanced techniques for efficient window navigation

Speed up window switching

Master quick navigation between windows.

Code

# Quick jump to numbered windows
Ctrl+A 0  # Fastest for frequently used windows
Ctrl+A 1
Ctrl+A 9

# Cycle through windows
Ctrl+A n      # Next
Ctrl+A p      # Previous
Ctrl+A Ctrl+A # Last active

# List windows with full details
Ctrl+A w

Execution

echo "For windows 0-9, use Ctrl+A + number"

Output

For windows 0-9, use Ctrl+A + number

Direct number access is fastest for frequent switches
Keep important windows at positions 0-3
Ctrl+A Ctrl+A is useful for two-window workflows

Configure custom window switching

Customize keybindings for faster window navigation in your workflow.

Code

# In ~/.screenrc - create custom bindings
# Example - use Alt+number for windows
bind 'M-1' select 1
bind 'M-2' select 2
bind 'M-3' select 3

# Or use simpler keybindings
bind 'h' select -1
bind 'l' select +1

Execution

echo "Configure .screenrc for custom keybindings"

Output

Configure .screenrc for custom keybindings

Custom keybindings require ~/.screenrc configuration
M- prefix refers to Meta/Alt key
Changes take effect after screen restart

Splitting Screens

Split windows horizontally and vertically

Horizontal and Vertical Splits

Split windows in different directions

Create screen splits

Create horizontal and vertical splits in screen windows.

Code

# Split horizontally (top/bottom)
Ctrl+A S

# Split vertically (left/right)
Ctrl+A |

# Create complex layouts
Ctrl+A S      # First split - creates top region
Ctrl+A Tab    # Move to new region
Ctrl+A c      # Create window in top region
Ctrl+A S      # Split again

# Remove current split
Ctrl+A X

Execution

echo "Use Ctrl+A S for horizontal, Ctrl+A | for vertical"

Output

Use Ctrl+A S for horizontal, Ctrl+A | for vertical

Horizontal split creates top/bottom regions
Vertical split creates left/right regions (in newer screens)
Each split region can display different windows
Vertical split may not work in older screen versions

Manage complex split layouts

Create and manage multiple grouped split regions.

Code

# Split the window in half
Ctrl+A S

# Switch to bottom region
Ctrl+A Tab

# Create another window in bottom
Ctrl+A c

# Split bottom region vertically
Ctrl+A |

# Navigate to each region
Ctrl+A Tab  # Cycle through regions

# Remove current region
Ctrl+A X

Execution

echo "Layouts: press Tab to cycle through split regions"

Output

Layouts: press Tab to cycle through split regions

Each split region is independent
Tab cycles through different regions
Better than tmux for simple side-by-side use cases

Navigate and Resize Splits

Move between and resize split regions

Navigate between split regions

Navigate effectively between split regions.

Code

# Move to next region
Ctrl+A Tab

# Move to top region
Ctrl+A Ctrl+I

# Display current region number
Ctrl+A Shift+I

# Switch to specific window in region
Ctrl+A 0-9  (in focused region)

# Rotate windows among regions
Ctrl+A C-T

Execution

echo "Tab to navigate regions, then 0-9 to switch windows"

Output

Tab to navigate regions, then 0-9 to switch windows

Tab is the primary method to move between regions
Once in a region, number keys switch windows within it
Visual feedback shows active region highlighting

Resize split regions

Adjust split region sizes for optimal viewing.

Code

# Resize current region (make larger)
Ctrl+A +  (expand downward)
Ctrl+A -  (shrink)

# Auto-fit region to content
Ctrl+A F

# Equalize all region sizes
Ctrl+A E

# Fine-tune sizing
Ctrl+A :resize height

Execution

echo "Use +/- keys to resize regions"

Output

Use +/- keys to resize regions

Plus/minus adjust region boundaries dynamically
Resize affects the current focused region
Works better in newer screen versions

Remove and Reset Splits

Clear splits and reset layouts

Remove and reset split regions

Clean up and remove screen splits when needed.

Code

# Remove current region
Ctrl+A X

# Remove all splits (show single region)
Ctrl+A Q

# Close all regions except current
Ctrl+A :only

# Reset layout to default
Ctrl+A :layout reset

Execution

echo "Ctrl+A X to remove current region, Q to remove all"

Output

Ctrl+A X to remove current region, Q to remove all

Ctrl+A X removes only current region
Ctrl+A Q removes all splits in window
Windows are preserved even when splits removed

Save and restore layouts

Save and restore frequently used split configurations.

Code

# Save current layout (named layout)
Ctrl+A :layout save workname

# List saved layouts
Ctrl+A :layout list

# Restore saved layout
Ctrl+A :layout load workname

# Switch between layouts
Ctrl+A :layout select workname

Execution

echo "Layout save/restore requires configuration"

Output

Layout save/restore requires configuration

Layout save feature available in screen 4.01+
Great for repeating complex split setups
Saves time in daily workflows

Copy/Paste and Scrolling

Copy text and navigate scrollback buffer

Copy Mode and Paste

Copy text from screen and paste it back

Enter copy mode and select text

Enter copy mode to select and copy text from screen history.

Code

# Enter copy/scroll mode
Ctrl+A [

# Move cursor in copy mode
- Use arrow keys to navigate
- Space to start selection
- Enter to copy selection
- Or use G to go to bottom

# Exit copy mode without copying
Escape

# Navigate in copy mode
h j k l  (vim style - if configured)
b      (back word)
f      (forward word)

Execution

echo "Press Ctrl+A [ to enter copy mode"

Output

Press Ctrl+A [ to enter copy mode

Copy mode shows scrollback buffer
Can mark and copy multiple times without exiting
Text stays in screen clipboard for pasting

Paste text and manage buffers

Paste previously copied text and manage multiple buffers.

Code

# Paste last copied text
Ctrl+A ]

# Show available paste buffers
Ctrl+A =

# Paste from specific buffer
Ctrl+A :paste buffer_name

# Copy directly from command
echo "text" | Ctrl+A [

Execution

echo "Use Ctrl+A ] to paste copied text"

Output

Use Ctrl+A ] to paste copied text

Ctrl+A ] pastes last copied selection
Multiple buffers allow you to save different text snippets
Clipboard is separate from system clipboard

Scrollback and Buffer Management

Navigate history and manage scrollback buffers

Navigate scrollback buffer

Navigate and search through terminal history.

Code

# Enter scrollback (scroll up in history)
Ctrl+A [

# Scroll up in history
Page Up  or  B

# Scroll down in history
Page Down  or  F

# Go to top of buffer
g      (go to top)
G      (go to bottom)

# Search in scrollback
/pattern   (forward search)
?pattern   (backward search)
n          (next match)

Execution

echo "Ctrl+A [ enters scrollback mode"

Output

Ctrl+A [ enters scrollback mode

Scrollback allows viewing past output
Search helps find specific text in history
Default scrollback is usually 100-1000 lines

Adjust scrollback buffer size

Configure and manage scrollback buffer size.

Code

# In ~/.screenrc - increase history
defscrollback 10000

# View current buffer size
Ctrl+A i

# Clear scrollback buffer
Ctrl+A C  (clears screen but not buffer)

# Set buffer per-session
screen -S work -X scrollback 5000

Execution

echo "Edit ~/.screenrc to set defscrollback"

Output

Edit ~/.screenrc to set defscrollback

Larger buffers use more memory
10000 lines is good default for most work
Per-window scrollback available in newer screen

Advanced Commands

Advanced screen configuration and automation

Configuration and Keybindings

Configure screen with ~/.screenrc

Create essential ~/.screenrc configuration

Configure screen with common settings in ~/.screenrc.

Code

# ~/.screenrc example
# Increase scrollback buffer
defscrollback 10000

# Set terminal type
term screen-256color

# Enable 256 colors
termcapeinfo xterm-256color 'Co#256:AB=\E[48;5;%dm:AF=\E[38;5;%dm'

# Disable startup message
startup_message off

# Set default window title
shelltitle '$ |bash'

# Automatically detach on hangup
autodetach on

# Enable visual bell
vbell on

# Set the command character
escape ^Aa

Execution

cat ~/.screenrc | head -15

Output

defscrollback 10000
term screen-256color
startup_message off

~/.screenrc is sourced when screen starts
Settings apply to all new screen sessions
Changes require restarting screen to take effect
Some settings can be overridden per-session

Custom keybindings configuration

Create custom keybindings matching your preferred workflow.

Code

# ~/.screenrc - custom keybindings
# Create new window (override default)
bind c new-window

# Vim-style navigation
bind h select -1
bind l select +1
bind j prev
bind k next

# Alt+number for windows
bind '^[1' select 1
bind '^[2' select 2
bind '^[3' select 3

# Custom split bindings
bind | split -v
bind - split

# Reload config
bind r source ~/.screenrc 'Reload complete'

Execution

echo "Add bindings to ~/.screenrc"

Output

Add bindings to ~/.screenrc

Control characters use format ^X (Ctrl+X)
Meta (Alt) characters use format ^[
Test new bindings before making permanent

Automation and Scripting

Automate screen with shell commands and scripts

Automate session creation with scripts

Automate screen session setup with shell scripts.

Code

#!/bin/bash
# Create automated development environment
SESSION="dev"

# Create session with first window
screen -S "$SESSION" -d -m

# Create and name windows
screen -S "$SESSION" -X new-window -t "editor"
screen -S "$SESSION" -X new-window -t "build"
screen -S "$SESSION" -X new-window -t "monitor"

# Send initial commands
screen -S "$SESSION" -p "editor" -X send-keys "vim" Enter
screen -S "$SESSION" -p "build" -X send-keys "cd ~/project" Enter

# Attach to session
screen -r "$SESSION"

Execution

echo "Script automates session setup"

Output

Script automates session setup

-p option specifies target window
send-keys sends keystrokes to session
Can chain multiple commands in script
Useful for standardizing team workflows

Send commands to running session

Send commands to active or background sessions remotely.

Code

# Send commands to unnamed session
screen -S mysession -X send-keys "ls -la" Enter

# Send to specific window
screen -S mysession -p 2 -X send-keys "npm test" Enter

# Send without Enter (for typing)
screen -S dev -X send-keys "git status"

# Run monitoring command
#!/bin/bash
while true; do
  screen -S monitor -X send-keys "clear" Enter
  date | screen -S monitor -X send-keys -
  sleep 10
done

Execution

echo "Use -X send-keys for automation"

Output

Use -X send-keys for automation

Useful for deployment and monitoring automation
Can integrate with cron for scheduled tasks
Combine with pipes for complex workflows

Tips and Tricks

Best practices and productivity tips

Best Practices and Workflows

Recommended patterns for effective screen usage

Organize projects into sessions

Organize work into sessions by project with task-specific windows.

Code

# Create sessions for different projects
screen -S frontend -d
screen -S backend -d
screen -S devops -d

# Each session contains logical windows
# frontend session
screen -S frontend -X new-window -t "editor"
screen -S frontend -X new-window -t "dev-server"
screen -S frontend -X new-window -t "tests"

# backend session
screen -S backend -X new-window -t "api"
screen -S backend -X new-window -t "database"
screen -S backend -X new-window -t "logs"

# List all project sessions
screen -ls | grep -E '(frontend|backend|devops)'

Execution

echo "Use sessions for projects, windows for tasks"

Output

Use sessions for projects, windows for tasks

Sessions isolate different projects
Windows organize tasks within a project
Easy to switch context without losing state
Works well for polyglot development

Monitor multiple servers from one session

Monitor multiple systems from one session with separate windows.

Code

# Create monitoring session
screen -S servers -d

# Create windows for each server
for server in web db cache load; do
  screen -S servers -X new-window -t "$server"
  screen -S servers -p "$server" -X send-keys \
    "ssh user@${server}.example.com" Enter
done

# Create summary window
screen -S servers -X new-window -t "summary"

# Monitor all with watch command
screen -S servers -p summary -X send-keys \
  "watch -n 5 'for s in web db cache load; do echo $s; ssh user@${s} uptime; done'" Enter

Execution

echo "Use same session for related monitoring"

Output

Use same session for related monitoring

One session per environment reduces context switching
Windows allow monitoring different aspects
Good for sysadmin and DevOps workflows

Common Workflows

Ready-to-use patterns for typical tasks

Web development workflow

Create a standardized web development environment.

Code

#!/bin/bash
# Web development setup
SESSION="web"
screen -S "$SESSION" -d -m

# Window 0: Code editor
screen -S "$SESSION" -X new-window -t "editor"
screen -S "$SESSION" -p "editor" -X send-keys "cd ~/projects/myapp && vim" Enter

# Window 1: Dev server
screen -S "$SESSION" -X new-window -t "server"
screen -S "$SESSION" -p "server" -X send-keys "cd ~/projects/myapp && npm start" Enter

# Window 2: Tests
screen -S "$SESSION" -X new-window -t "test"
screen -S "$SESSION" -p "test" -X send-keys "cd ~/projects/myapp && npm test" Enter

# Window 3: Git/shell
screen -S "$SESSION" -X new-window -t "shell"
screen -S "$SESSION" -p "shell" -X send-keys "cd ~/projects/myapp && bash" Enter

# Attach to session
screen -r "$SESSION"

Execution

echo "Save as startup script for web projects"

Output

Save as startup script for web projects

Saves time on setup for new projects
Ensures consistent window organization
Easy to extend with more tools

System administration quick reference

Organize server management tasks efficiently with splits.

Code

# Quick reference for sysadmins
# Session per environment:
screen -S prod   # Production monitoring
screen -S staging  # Staging environment
screen -S dev    # Development/testing

# In each session, split regions for:
# - Top: Monitoring (top, htop, watch)
# - Bottom-left: Logs (tail -f logfile)
# - Bottom-right: Services (systemctl commands)

# Workflow in session:
Ctrl+A S           # Split horizontally
Ctrl+A c           # Create window in top
Ctrl+A Tab         # Move to bottom
Ctrl+A |           # Split vertically
Ctrl+A c           # Create window bottom-left
Ctrl+A Tab         # Move bottom-right
Ctrl+A c           # Create window bottom-right

# Load baseline services in background
screen -d -m "systemctl status"

Execution

echo "Sysadmin can leverage splits for complex monitoring"

Output

Sysadmin can leverage splits for complex monitoring

Splits allow monitoring multiple aspects simultaneously
Useful for complex troubleshooting
Saves window switching time during incidents

Screen

Getting Started

Installation and Basics

Accessibility

Best Practices

Common Errors

Keywords

Install Screen on Linux

Start Screen without a session name

Understanding Screen Concepts

Accessibility

Best Practices

Common Errors

Keywords

Understanding screen session and window hierarchy

Check current screen setup

Creating Your First Session

Accessibility

Best Practices

Common Errors

Keywords

Create a named screen session

Attach to a session

Session Management

Create and Attach Sessions

Accessibility

Best Practices

Common Errors

Keywords

Create multiple independent sessions

Attach and detach from sessions

List and Monitor Sessions

Accessibility

Best Practices

Common Errors

Keywords

List all screen sessions with details

Monitor and manage session processes

Kill and Destroy Sessions

Accessibility

Best Practices

Common Errors

Keywords

Properly terminate screen sessions

Handle zombie and dead sessions

Window Management

Create and Switch Windows

Accessibility

Best Practices

Common Errors

Keywords

Create new windows in a session

Switch between windows efficiently

Manage and Close Windows

Accessibility

Best Practices

Common Errors

Keywords

Rename and manage windows

Close windows and manage cleanup

Window Navigation Tips

Accessibility

Best Practices

Common Errors

Keywords

Speed up window switching

Configure custom window switching

Splitting Screens

Horizontal and Vertical Splits

Accessibility

Best Practices

Common Errors

Keywords

Create screen splits

Manage complex split layouts

Navigate and Resize Splits

Accessibility

Best Practices

Common Errors

Keywords