Tmux is a terminal multiplexer popular in Linux world. Tmux provides multiple windows in a single session. Tmux also has the ability to detach and run after disconnect and attach after connection. This is very useful for system administrators.
What Is Tmux?
Tmux is described as terminal multiplexer. This terms means a single terminal can be used like multiple terminal. Tmux is based command line interface where there is no need to run a graphical interface. Tmux can provide multiple windows like different pages and each window may have single or multiple panes which divides current window visually.
Tmux Advantages and Usecases
Tmux is a popular tool between system administrators and geeks with its lifesaver features. Tmux provides the following advantages and uses cases that make it superior to other terminals.
- Tmux can run multiple sessions at the same time.
- Even SHH or remote connection drops Tmux can continue reconnecting existing sessions.
- Tmux can be used run commands continuously even the connection lost.
- Tmux can be managed completely with key shortcuts.
- Tmux requires very very low system resources.
Install Tmux
Installation of the tmux is very easy on Linux distributions like Ubuntu, Debian, Mint, Kali, Fedora, CentOS, RHEL etc.
Ubuntu, Debian, Mint, Kali:
$ sudo apt install tmux
Fedora, CentOS, RHEL:
$ sudo dnf install tmuxTmux Man Page
The manpage of tmux provides a lot of detailed features. To get more information man page of tmux can be used like below.
$ man tmux
Start Tmux
Tmux is a terminal emulator that acts as a shell. Tmux can be started as a shell too. Just run tmux command we will get tmux screen by clearing the existing shell screen.
$ tmux
Bind Key
Tmux uses CTRL+b for operation key which means to use shortcuts of tmux CTRL+b should be prefixed with the related keyboard shortcut.
CTRL+b
List Current Key Bindings
Tmux mainly used with keys with bind keys. These key bindings can be listed with the following command. As we can see from the following screenshot there are a lot of key bindings provided by tmux.
CTRL+b :list-keys
Start New Window
One of the most useful functionalities of the tmux is operating multiple windows. Existing windows are listed in the green bar below. Creating a new window will create a new shell like a new tab in terminal emulators.
CTRL+b c
Move Next Window
While working with multiple windows navigation between windows can be done in different ways. One of the most common usages is switching the next window with the following key short cut.
CTRL+b n
After switching the asterisk which shows the current desktop will put a new window afterward.
Move the Previous Window
This is similar to moving the next window. Just type following keyboard shortcut.
CTRL+b p
Move To The Specified Window Number
Another useful navigation feature is using window number to navigate. Window numbers can be seen below of the terminal before the window name.
CTRL+b <number of window>
Rename Window
Normally tmux sets current running application name as window name. If we are using a lot of windows for multiple operations and we want to rename the window name.
CTRL+b ,
What Is Pane?
The pane is used to multiplexing a single window. Using multiple commands in a single-window is very useful and popular usage. Below we can see two horizontal pane. We will look at how to create panes below.
Create New Vertical Pane
The current window can be divided into two vertical panes with the CTRL+b %.
CTRL+b %
After creating a pane current working pane will change to the new pane and active pane can be seen in the line between panes. The lower part of the line is yellow which means left pane is active.
New Horizontal Pane
Horizontal pane can be created with CTRL+b ".
CTRL+b "
Move and Navigate Between Panes
To move between panes direction keys can be used like below.
Move Left Pane
CTRL+b <left arrow>
Move Right Pane
CTRL+b <right arrow>
Move Below Pane
CTRL+b <down arrow>
Move Upper Pane
CTRL+b <up arrow>
Show Pane Numbers
While working multiple pane it can be useful to show pane numbers. Pane numbers can be shown according to their location with the command below. While showing pane number in the upper left corner of the pane the size is also shown.
CTRL+b q
Close Pane
If we have finished our job with a pane we generally close it to make things clean. We can close the current pane with the following shortcut.
CTRL+d
OR
:exit
Copy Text
One of the most important features is copying and pasting text from the terminal. Tmux provides a bit different method to copy-paste. Normally console provided copy paste can be used but if the source is multiline text it can be impossible to copy properly. Below are the steps to copy the text.
Start Copy Mode
CTRL+b [
Set Start Point
We can move the cursor to the start of the copy range in the copy mode and after that to set the starting point following command is used.
CTRL+<space>
Set End Point
Move the cursor and we see can see the current selection is in orange color. To set endpoint and copy the contents to the buffer use following command.
ALT+w
Paste
Copied text will be put into the buffer. We can use this text wherever we want. We can also access this text in tmux from different windows.
CTRL+b ]
Create Session
Creating a tmux session is just starting tmux. But we can also provide some parameters like the name.
$ tmux new -s mysession
List Sessions
There may be more than one tmux sessions. These sessions can be listed with the following command.
CTRL+b s
Detach Tmux
The existing session can be detached like below. This will not end the session thus this will only detach session from the current shell and it will continue running in the background.
CTRL+b d
Reattach
Attaching session means reconnecting currently running session which is detached before.
$ tmux a
Configuration File
There is to path where the configuration file resides. /etc/tmux.conf and ~/.tmux.conf.