Execute command in one terminal and get the output in another terminal it it possible ? how?

Question

Execute command in one terminal and get the output in another terminal

Answer 1

Possible with something known as named pipe.

Here's a basic demo:

1. Open terminal window 1.
2. Type mkfifo /tmp/myPipe and hit enter
3. Type echo "Hello Named Pipe" > /tmp/myPipe & and hit enter
4. Open terminal 2
5. Run cat /tmp/myPipe to see the output

Another possible solution is to have a screen session running, and attach/detach to it.

Answer 2

On the receiving terminal, execute the command w. This will print a list of currently running sessions, e.g. when I run the command, it prints:

 13:39:22 up 11 min,  3 users,  load average: 0.32, 0.50, 0.33
USER     TTY      FROM             LOGIN@   IDLE   JCPU   PCPU WHAT
sebastia tty8     :0               13:27   11:52  21.10s  0.31s cinnamon-session --session cinnamon
sebastia pts/1    :0               13:36   10.00s 23.90s  0.29s sudo apt-get update
sebastia pts/3    :0               13:37    1.00s  0.11s  0.01s w

The one you're in is of course the one with the command w (Listed in the column WHAT).

In this list, you'll also find a section called TTY. There you will see the name of the terminal buffer file, e.g. pts/3 for the one I executed w in.

Now let's assume I want to execute the command running in pts1 to print its output to pts3. This can be done like this (using the command from above):

sudo apt-get update > /dev/pts/3

This will forward all output to pts3. However, it will not take any input from there. Unfortunately, I didn't manage to find a solution for this. (Additions welcome)

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Depending on what you are trying to achieve, a terminal multiplexer, such as Tmux or GNU Screen may be better suited for this task. e.g. with Tmux, proceed as follows:

Start Tmux with the command tmux. You'll be dropped to a new shell. Execute your command there.

In the receiving terminal, run tmux a to attach to the existing Tmux session. You can now interact with this terminal.

If you wish to do so, you can detach from Tmux anytime with Ctrl+B, followed by D. You can reattach from anywhere with tmux a.