QProcess crashes

[beowulf]

I'm trying to verify if the process is already running, if it's running closes and creates a new process.

@QProcess *MyProcess;@

@ if(MyProcess!= NULL)
{

    MyProcess->kill();

}

MyProcess = new QProcess(this);@

My application crashes!

[MuldeR]

Just because the pointer "MyProcess" is not NULL, doesn't mean it's a valid pointer!

It might be a dangling pointer, i.e. a pointer to an object that has already been deleted/destroyed.

Any attempt to dereference a dangling pointer will result in undefined behavior (crash).

[Chris Kawa]

Besides the fact that you don't actually initialize MyProcess variable to NULL (maybe in your code you do) it's not the way to check if process is running. there is a method state() that returns current state of the process - not running, running or starting.

[beowulf]

Even if the checking process status he continues crashing

@ if(MyProcess->state() == QProcess::Running)
{

    MyProcess->kill();

}@

[MuldeR]

You still are dereferencing the "MyProcess" pointer. But is that pointer valid at all ???

I mean: Do you assign the address of a QProcess object to that pointer before you try to dereference?

Also, as said before, you also have problem if the object has already been deleted/destroyed...

(If you get a crash on pointer access, it's almost always either a NULL pointer or a dangling pointer!)