Shell Programming and Scripting

Hi ALL,

Is there any way to pause a running process under nohup ?
I have fired a build commands with required flags under nohup as below. now how can
I pause the started build process.

nohup make DEVICE=ap DEBUG=1 &

I understand we can use ctrl + z to pause a foreground process but no idea about background.


Thanks.......................

You might find that sending signal SIGSTOP to the process might suffice.

On my server, it is signal number 17, so:-

Code:

kill -17 process-id

For me signal SIGCONT to continue is 19.

Have a look at man signal top confirm the signals and their number for your installation, just to be sure. Do lots of testing too.



I hope that this helps,
Robin
Liverpool/Blackburn
UK

Thanks Robin for the reply.
can we map this signal generation to a hot key some how ? i need a convenient way of doing this .
where there are multiple parallel processes running under make ,i need to send signal all those processes and is not
convenient to me. i need a way similar to cntrl+z which should collect all the pids info under nohup and
send SIGSTOP in one go.

When you put something into the background (with or without nohup) you effectively disconnect it from the terminal. You could bring it back under terminal control by bringing it back into the foreground again.

When you start a process in the background from the command line, you will see the following sort of thing on the screen:-

Code:

sleep 500 &
[1]     10665

The number in square brackets is the job id and the number after is the process id. You can bring it back to the foreground with the command:-

Code:

fg %1

... or ...

Code:

fg 10665

So, use a percentage % marker to show it is the job id, or just use the process id. You will then be able to suspend it with a CNTL-Z as usual.

To restart it in the foreground, it is just as before. You can restart it in the background as either

Code:

bg %1

... or ...

Code:

bg 10665

I'm not sure about programming a keystroke to fire of a mass suspend. You might be able to do that with trap on signal 18, but then you disable CNTL-Z from your running shell.


I'm not sure if this is going to be easy to acheive. Could you not code up a function for the above suggestion, something like:-

Code:

$ cat newfunc
#!/bin/ksh

suspall()
{
jobs | tr -d "[]" | while read jobid rest
do
   kill -17 %$jobid
done
}

If you either include this in your .profile or have in in a script you can source in like this . newfunc, then from the command line, you would be able to do the following:-

Code:

$ . newfunc
$ sleep 500 &
[1]     266546
$ sleep 500 &
[2]     221692
$ sleep 500 &
[3]     123282
$ sleep 500 &
[4]     221416
$ sleep 500 &
[5]     174586
$ suspall
[1] + Stopped (SIGSTOP)        sleep 500 &
[2] - Stopped (SIGSTOP)        sleep 500 &
[3]   Stopped (SIGSTOP)        sleep 500 &
[4]   Stopped (SIGSTOP)        sleep 500 &
[5]   Stopped (SIGSTOP)        sleep 500 &
$

Does this help?


Robin