How can I keep my Linux program running after I exit ssh of my non-root user?

Question

I've searched, googled, sat in IRC for a week and even talked to a friend who is devoutly aligned with linux but I haven't yet received a solid answer.

I have written a shell script that runs as soon as I log into my non-root user and runs basically just does "./myprogram &" without quotation. When I exit shh my program times out and I am unable to connect to it until I log back in. How can I keep my program running after I exit SSH of my non-root user?

I am curious if this has to be done on the program level or what? My apologizes if this does not belong here, I am not sure where it goes to be perfectly honest.

Answer 1

You might also want to use the batch (or at) command, in addition to the other answers (nohup, screen, ...). And ssh has a -f option which might interest you.

Answer 2

Beside using nohup, you can run your program in terminal multiplexer like screen or tmux. With them, you can reattach to sessions, which is for example quite helpful if you need to run terminal-based interactive programs or long time running scripts over a unstable ssh connections.

boybu is a nice enhancement of screen.

Answer 3

There's two signals that can cause your program to die after your ssh session ends: SIGHUP and SIGPIPE.

SIGHUP will be sent to your program because the parent process (ssh) has died. You can get around this either by using the program nohup (i.e. nohup ./myprogram &) or by using the shell builtin disown (./myprogram& disown)

SIGPIPE will be sent to your program if it tries to write to stdout or stderr after the ssh session has been disconnected. To get around this, redirect them to a file or /dev/null, i.e. nohup ./myprogram >/dev/null 2>/dev/null &

Answer 4

Try nohup: http://linux.die.net/man/1/nohup

Likely your program receives a SIGHUP signal when you exit your ssh session.