Process getting SIGHUP

[Deepak Extross]

Hi,

I have this script, say start_procs.sh, that starts up some executables in the background with
' su - -c "nohup &" '
When I invoke this script from the command-prompt, all is well - the processes start, and continue to run in the background till they are explicitly 'kill'ed.

Funny thing is, when I invoke start_procs.sh from the startup file /etc/rc, the processes get a SIGHUP as soon as start_procs.sh exits.

Where am I goofing up?

[Roger Baptiste]

Deepak,

If you want to start the scripts as a part
of bootup process, it should be a run-level
startup script under /sbin/init.d directory
with a link to /sbin/rc3.d/Snnn<script> .

There should be a template file in the
/sbin/init.d directory. Make a copy of
it and modify the contents under "start"
case option to include the command
"su xx -c "...." .

/etc/rc is not the correct location
to start off user-defined scripts, since
the system is not completed its booting
process.

-R

[Deepak Extross]

R,
Tried that too. But the problem remains - the processes start up, but get signal 1 when my script exits.

-deepak.

[Eugen Cocalea]

Hi,
Try with:

su - -c "nohup 1>/dev/null &"

E.

[harry d brown jr · Accepted solution]

during boot, rc will kill all child pocesses on exit.

Instead of:

su - -c "nohup &"

Try "nohup'ing" your "su"

nohup su - -c " " &


live free or die

harry

[Eugen Cocalea]

Hi again,

Oops, I should have seen that :) given the fact that I tried several times to get the SIGHUP and didn't succeed (worked as you wanted).

E.

[Frank Slootweg]

nohup(1) takes some time to startup and do its work. Because of the "&", the nohup command is started in the background and the calling script continues. If the calling script terminates quickly, it will terminate before nohup has had the chance doing its work and hence the nohup-ed command will still get a SIGHUP signal.

A hack workaround for this is to put a small (few second) sleep command after the "... nohup ...&" to allow nohup to do its work.

A better method is to check (with ps(1)) in a loop if the nohup-ed command has actually started. If not, loop. If so, exit from the loop.

[Deepak Extross]

Thanks to all who chipped in.
Harry gets full marks for cracking this one!