[Qucs-devel] killing qucsdigi

[Raimund 'R. J. <ra...@lk...>]

hey folks!

Stefan told me that there is a problem with the qucsdigi script not
being possible to be killed using the 'cancel' button of the simulation
window.

i spent some time playing around with the problem and found out this:
Currently there is a QProcess::kill() that terminates the qucsdigi
script. according the docs it might be better to use tryTerminate() first:

http://doc.trolltech.com/qtopia1.7/html/qprocess.html#kill

but there still is the problem that only the qucsdigi script itself is
killed, not its children. this can be solved by not killing the process
itself but the entire process group. this is easily done with kill(2)
but i see no QT API for it.

it would be possible to do that from the qucsdigi script itself. adding
this at the beginning of qucsdigi:

trap 'kill 0; exit 0' SIGINT SIGTERM

would make it kill all children when it receives the INT or TERM signal
(which is what QProcess::kill/tryTerminate should do).

for this to work each invocation in the script would have to be changed:

echo -n "Doing something ..."
$something
echo "done"

to

echo -n "Doing something ..."
$something &
wait $!
echo "done"

i still not fully understand why this is neccessary, but that might work.

Want me to create a patch for this?

	Raimund

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