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KProcess doesn't launch child process while debugging.

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SmartyHias

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  • "SmartyHias" started this thread

Posts: 2

Location: Munich - Germany

Occupation: Computer freak

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1

Friday, December 17th 2004, 12:47pm

KProcess doesn't launch child process while debugging.

Hi there !

I need to launch an application from within my application. Since I also need to be informed, when the child process exits (ie crashes etc.) I want to use the KProcess class.
It works perfectly as long as I am not starting it in debugging mode from within KDevelop. When I want to debug my application, then it just won't start the child process. I have found some statements on the internet, saying, that this is a known Problem, but I haven't found a solution to it yet.
You can try it very simply in your own application. Just add the following lines somewhere in your code (plus #include <kprocess.h> of course). When you start your application from commandline it launches kwrite. In debugging mode it won't.

Quoted


KProcess procTest;
procTest << "kwrite";
procTest.start(KProcess::DontCare);


I would appreciate some tips how to avoid this problem, since I really need to debug my code :-)

SmartyHias

anda_skoa

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Location: Graz, Austria

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Friday, December 17th 2004, 5:16pm

Just to make sure: your process instance is created on the heap somewhere or a member of another class and stays around, does it?
Your code snippet looks like a local variable which will be deleted when the method returns.

Cheers,
_
Qt/KDE Developer
Debian User

SmartyHias

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  • "SmartyHias" started this thread

Posts: 2

Location: Munich - Germany

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3

Friday, December 17th 2004, 5:59pm

Well, I also checked this. It doesn't matter if I instantiate the object by "new" or just as a local instance. Especially if I am starting the process with "KProcess::DontCare".
Besides it works perfectly fine when staring the application from shell. It just seizes to work when starting it with gdb. KDE-gdb or ddd-gdb doesn't make a difference.
You can try it yourself real quick, if you want. Just make a new project using a simple KDE-Application (Hello world or so). insert the 3 lines in the c-tor of your KMainWindow derived class. (it also doesn't matter if you put it into the c-tor or eg. a slot :-) ). build it and run it from a shell first and then using gdb.
Funny, but nasty little bug :-)

Have a nice evening

SmartyHias