2

I frequently execute programs that take a long time on several remote servers:

for NUM in {1..100}; do ssh host-{NUM}.mydomain.com /usr/bin/takesalongtime; done

Most of the time I let this run in background (i.e. in a terminal emulator while doing something else) and wait for it to finish. However, sometimes I need to break the loop and continue or re-run it later.

Is there a way to stop such a loop running in an interactive bash after the current iteration without killing the current ssh or takesalongtime program in the process?

I.e. I want to do something, so that the loop behaves like I inserted a break; between the ssh command and done, so that it breaks the loop after completing takesalongtime on the current remote host.

2

Find the pid of the shell and send it a sigint. This will not stop the ssh, but when it finishes the shell will handle the signal and end the loop.

$ for i in {1..100}; do ssh -n localhost 'sleep 9;date'; done

in other terminal

$ ps fax
10636 ?        S      0:00          |   \_ xterm
10638 pts/2    Ss     0:00          |       \_ bash
12164 pts/2    S+     0:00          |           \_ ssh -n localhost sleep 9;date
$ kill -int 10638

If you have backgrounded the command by adding & to the end you can use kill -hup on the backgrounded shell.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.