How to use the tmux command prompt

One-off tmux commands are easy to aim at the wrong session when they are typed from another shell. The interactive command prompt runs commands from the attached client, so the current session, window, and pane are already the default target unless the command names a different one.

The default key sequence is Ctrl-b then :. Ctrl-b is the prefix key, and : opens the command-prompt binding in the status-line area where tmux accepts the command name and arguments without the leading tmux shell command.

Prompt commands use the same parser as ~/.tmux.conf and other tmux command strings. Use one read-only command first in shared or long-running sessions, because command sequences separated with semicolons run immediately and state-changing commands such as rename-window, source-file, and kill-pane affect the live server.

Steps to use the tmux command prompt:

Attach to the tmux session that should receive the prompt command.
```
$ tmux attach -t work
```
Replace work with the target session name. Skip this step when the correct tmux client is already attached.

Related: How to attach to a tmux session
Confirm the default colon binding from a shell when the prompt key does not open.
```
$ tmux list-keys -T prefix :
bind-key -T prefix : command-prompt
```
The output means the prefix table maps : to command-prompt. If the prefix key changed, press the configured prefix before :.

Related: How to change tmux prefix key to Ctrl-a
Related: How to customize a tmux key binding
Open the prompt inside the attached client.
```
C-b :
```
With the default prefix, press Ctrl-b, release it, then press :. The prompt appears in the status-line area; press Escape to cancel an empty prompt without running a command.
Run a read-only command from the prompt.
```
: display-message -p '#{session_name}'
work
```
display-message -p expands the tmux format and prints the selected session name. Press Enter to run the command; Tab can complete command names and arguments in the prompt.
Open the prompt again before entering a separate command.
```
C-b :
```
The prompt closes after each command runs. Use C-b ~ to show recent tmux messages again when status-line output disappears too quickly.
Rename the current window from the prompt.
```
: rename-window admin
```
rename-window changes the tmux title for the active window only.

Related: How to rename a window in tmux
Verify the new window name from the prompt.
```
: display-message -p '#{window_name}'
admin
```
The printed name confirms that tmux accepted the command typed at the prompt and applied it to the active window.

Author: Mohd Shakir Zakaria
Mohd Shakir Zakaria is a cloud architect with deep roots in software development and open-source advocacy. Certified in AWS, Red Hat, VMware, ITIL, and Linux, he specializes in designing and managing robust cloud and on-premises infrastructures.