Executing commands on a remote machine

JDska55 · 06-29-2009, 11:52 AM

Hey all-
I'm wondering if there's a way to issue commands toa remote machine without having the terminal actaully log in to the remote machine. Basically, I want to tell the remote box to run a script that I scp'd into it earlier in the script. Here's what I'm thinking:

Code:

do
  addarray[$count]="$address"
  ((count++))
  rsync -e "ssh -i `echo ~`/.ec2/gsg-keypair" -avz /home/admin/data root@${address}:/root
  scp -i ~/.ec2/gsg-keypair ~/Kai-script root@${address}:/root
  ssh -i ~/.ec2/gsg-keypair root@${address}
done

I've been using the ssh and then executing the script on the remote machine, but that means I have to wait till it's done running before I can exit and get back into the script on my home machine. Since that takes about 2 hours, it's not exactly convenient

. Any thoughts?

Cheers,
Jarrod

Dinithion · 06-29-2009, 12:29 PM

Check out nohup, i.e. By using nohup commands can finnish after you logout. By adding a & to the command, it will be runned in the background. I thing you should be able to fix it that way

farslayer · 06-29-2009, 01:18 PM

screen is your friend.

http://www.linuxdynasty.org/screen-howto-part-1.html

http://jmcpherson.org/screen.html

http://www.rackaid.com/resources/lin.../using-screen/

JDska55 · 06-30-2009, 01:18 PM

Hm... I don't think screen is what I'm looking for. I only need one terminal up locally, I just need to be able to exit from remote machines and have them keep running their script. i tried doing nohup bash myscript &, but it hung up for some reason, never returning me to the prompt...

xxloaf · 06-30-2009, 01:26 PM

Quote:

Originally Posted by JDska55

Hm... I don't think screen is what I'm looking for. I only need one terminal up locally, I just need to be able to exit from remote machines and have them keep running their script. i tried doing nohup bash myscript &, but it hung up for some reason, never returning me to the prompt...

This is still doable with screen.

Once you login to the remote machine execute "shell".

Once you are inside of the shell you can then execute your command, once you have done so you can detach the shell while the command still runs.

Code:

ctrl-a-d

This will detach the shell, even if you log out of the remote machine the command will still be running.

Once you return to the machine you just run 'screen -r' to bring the shell back.

JDska55 · 06-30-2009, 01:45 PM

Thanks for the tips! It appears that screen will work for this. The concept is still a bit hazy to me, but as long as it works, I'm okay with it. Thanks!

farslayer · 06-30-2009, 03:04 PM

The ability to re-attach to a screen session is one of the cool features, that I really like..

I used to host some game servers on Linux and would run them in screen sessions so I could remote into the system attach to the screen to manage the server, detach then log off the remote box.

I had a consultant remote into a system once and he ran a screen session which we then attached to locally so we could watch everything he did on the server.. Was rather slick.