How to create a new terminal session and execute multiple commands

Question

I'm looking for a way to automate the start-up of my development environment. I have three virtual machines that have to be started, then have to ssh to each of them and open VPN on them.

So far I've gotten them to start and managed to ssh to them:

#!/bin/sh 
virsh start virtual_1
virsh start virtual_2
virsh start virtual_3
sleep 2m

gnome-terminal --title "virtual_3: server" -x ssh [email protected] &
gnome-terminal --title "virtual_2: 11.100" -x ssh [email protected] &
gnome-terminal --title "virtual_1: 12.100" -x ssh [email protected] &

How do I execute an additional command in each of the terminals which starts openvpn?

For simplicity I'm trying to echo 1 in each terminal instead of starting VPN.

I've found that multiple commands on terminal start can be run like:

gnome-terminal -x bash -c "cmd1; cmd2"

So for one terminal to keep it simple I changed:

gnome-terminal --title "virtual_3: server" -x ssh [email protected] &

to:

gnome-terminal --title "virtual_3: server" -x bash -c "ssh [email protected] ; echo 1" &

But 1 wasn't printed in the terminal of virtual_3. Then I thought, maybe the command is being executed too quickly, before the terminal is ready, so I tried adding &&:

gnome-terminal --title "virtual_3: server" -x bash -c "ssh [email protected] &&; echo 1" &

But that gave no result either.

Community · Accepted Answer · 2020-06-20 09:12:55Z

11

First of all, if you run

gnome-terminal -x bash -c "cmd1; cmd2"

you get bash to execute cmd1 and cmd2. It doesn't first execute cmd1 and then give cmd2 to its result. ssh is a program run in the terminal and your cmd2 won't be executed until that is finished.

So you need to run ssh and tell that to execute your command.

You can do so by:

ssh user@address "command_to_execute"

However, ssh exits after the command is finished. As you can see in "With ssh, how can you run a command on the remote machine without exiting?", you can execute ssh with the -t option so it doesn't quit:

ssh -t user@address "command_to_execute"

So your command in the end becomes:

gnome-terminal --title "virtual_3: server" -x bash -c "ssh -t [email protected] 'echo 1'"

You are right, giving -t alone is not enough (although necessary). -t allocates buffer for the tty but doesn't execute bash for you. From the manual of ssh:

-t Force pseudo-tty allocation. This can be used to execute arbitrary screen-based programs on a remote machine, which can be very useful, e.g. when implementing menu services. Multiple -t options force tty allocation, even if ssh has no local tty.

If command is specified, it is executed on the remote host instead of a login shell.

So what you need is, to execute bash your self. Therefore:

ssh -t user@address "command_to_execute; bash"

edited Jun 20, 2020 at 9:12

CommunityBot

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answered Jul 16, 2012 at 8:43

Shahbaz

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1 Comment

TheMeaningfulEngineer Over a year ago

Tnx for the reply, however it didn't work it just opens and closes immediately . Here is what I tried directly from the console to see whats it outputting (since it closes to fast). input: ssh [email protected] 'echo 1' output: 1 input: ssh -t [email protected] 'echo 1' output: 1 Connection to 192.168.1.132 closed.

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