Linux multi window terminal Screen and Tmux

Screen allows for multi window connection using a single ssh session. It also allows to detach from the session screen while still running a remote session.

Install

sudo apt-get install screen

Key terms

• window -it's a separate window that you can switch between
• region -your terminal screen can be divided in regions where each can hold multiple windows

Useful key bindings

C^a c -create new prompt
C^a tab -move to a next window
C^a | -split vertically
C^a S -split horizontly
C^a \ -kill all windows, terminate any ssh sessions and exit GNU Screen program

Key	Action	Notes
Ctrl+a c	new window
Ctrl+a n	next window	I bind F12 to this
Ctrl+a p	previous window	I bind F11 to this
Ctrl+a "	select window from list	I have window list in the status line
Ctrl+a Ctrl+a	previous window viewed
Ctrl+a S	split terminal horizontally into regions	Ctrl+a c to create new window there
	split terminal vertically into regions	Requires screen >= 4.1
Ctrl+a :resize	resize region
Ctrl+a :fit	fit screen size to new terminal size	Ctrl+a F is the same. Do after resizing xterm
Ctrl+a :remove	remove region	Ctrl+a X is the same
Ctrl+a tab	Move to next region
Ctrl+a d	detach screen from terminal	Start screen with -r option to reattach
Ctrl+a A	set window title
Ctrl+a x	lock session	Enter user password to unlock
Ctrl+a [	enter scrollback/copy mode	Enter to start and end copy region. Ctrl+a ] to leave this mode
Ctrl+a ]	paste buffer	Supports pasting between windows
Ctrl+a >	write paste buffer to file	useful for copying between screens
Ctrl+a <	read paste buffer from file	useful for pasting between screens
Ctrl+a ?	show key bindings/command names	Note unbound commands only in man page
Ctrl+a :	goto screen command prompt	up shows last command entered

Scroll back - a copy mode

In GNU Screen press Ctrl + a + [ or C^a C^ESC to enter Copy Mode, then scroll up/down using keys j or k. Below are some other navigation keys:

h -    Move the cursor left by one character
j -    Move the cursor down by one line
k -    Move the cursor up by one line
l -    Move the cursor right by one character
0 -    Move to the beginning of the current line
$ -    Move to the end of the current line.
G -    Moves to the specified line
       (defaults to the end of the buffer).
C-u -  Scrolls a half page up.
C-b -  Scrolls a full page up.
C-d -  Scrolls a half page down.
C-f -  Scrolls the full page down.

Define scrollback buffer size start screen with the following key (5000 lines in this example):

screen -h 5000

Update: You can use activate copy mode of GNU Screen also by Ctrl + Esc that might be more useful than Ctrl + a + [ shortcut (thanks to Yu-Jie Lin for this tip).

Custom configuration

By default the config is kept in ~/.screenrc file but using -c option we can pass a custom config

~$ screen -c screen-4regions

Example of a config file:

~$ cat screen-pm 
# Region 0
screen -t mail1-queue     #creates new terminal/prompt
select 0                  #select window0
stuff "echo Window0^M"    #echo a string between quotes, ^M translates to EOL
stuff "sshpass -p 'password' ssh -o PubkeyAuthentication=no root@example.com^M"  #ssh interactively
 
split      #split horizontally
split -v   #split vertically

# Region 1 
select 1
focus                   #get focus on a selected region
screen -t mail2-queue   #create a new terminal/prompt in the focus window
stuff "echo Window1^M"

# Region 2
select 2
focus
screen -t mail1
stuff "echo Window2^M"

split -v

# Region 3
select 3
focus
screen -t mail2
stuff "echo Window3^M"

altscreen on                                                                                       
term screen-256color                                                                               
bind ',' prev                                                                                      
bind '.' next                                                                                      
#                                                                                                  
#change the hardstatus settings to give an window list at the bottom of the                        
#screen, with the time and date and with the current window highlighted                            
hardstatus alwayslastline                                                                          
#hardstatus string '%{= kG}%-Lw%{= kW}%50> %n%f* %t%{= kG}%+Lw%< %{= kG}%-=%c:%s%{-}'              
hardstatus string '%{= kG}[ %{G}%H %{g}][%= %{= kw}%?%-Lw%?%{r}(%{W}%n*%f%t%?(%u)%?%{r})%{w}%?%+Lw%?%?%= %{g}][%{B} %m-%d %{W}%c %{g}]'

References

• User Guide HTML one page