How to detect a QProcess is started

**^NyAw^** · 20th June 2008, 09:20

Hi,

Take a look at QProcess::finished signal

**cooler123** · 20th June 2008, 10:53

Oops, my mistake.
I actually need to know when the process A actually started and not finished running.

**mazurekwrc** · 20th June 2008, 11:13

maybe stateChanged ( QProcess::ProcessState newState ) signal will help you ?

**cooler123** · 20th June 2008, 11:24

I use startDetached to start the process that will not affect my main application.
I have try all the signal, started, finished, stateChanged... all also not working. No signal is returned.

**jacek** · 22nd June 2008, 23:34

Originally Posted by cooler123

I use startDetached to start the process that will not affect my main application.
I have try all the signal, started, finished, stateChanged... all also not working. No signal is returned.

QProcess::startDetached() is a static method, so there is no QProcess object you can connect to to receive the signal from. Use QProcess::start() instead.

**cooler123** · 23rd June 2008, 03:35

After i use start() to start the process, can I detached it after that?

**jacek** · 24th June 2008, 23:07

Originally Posted by cooler123

After i use start() to start the process, can I detached it after that?

No, you can't. QProcess will kill its child processes. Maybe you could someway determine the state of child process if you had its PID?

**The Storm** · 25th June 2008, 18:43

Why you need to detach the child process? If you don't call the waitForFinished() function the child process will not block your application and you will be able to monitor it well.