Handling a signal with a class member function

[Zipi]

Hello,
i am using the sigaction function to handle the SIGCHLD signal.Is it possible to use a class member function as the handler function (the sa_handler member of the sigaction structure)?
The function's signature is:

void (*sa_handler)(int);

I could use a static member function with such a signature,but i wouldn't be able to pass an "handle" to the actual object instance.
Is a global variable the only solution to this? Or is there some trick i could use?

Thanks in advance!

[gerard4143]

Just curious...why does it have to be a class member?

[Zipi]

Just cause i would like to avoid global stuff

But if that's the only way....oh well,i tried

[gerard4143]

Are you saying you avoid all functions....even class member functions

[Zipi]

Ok,so now i'm using a global variable to keep track of the pid of interest and a static member function to handle the SIG_CHLD signal.

The member function is:

void MyClass::CallWaitChildProcess(int signo) 
{          
    int status, child_val;

	if (waitpid(g_ChildProcessPid, &status, WNOHANG) < 0) 
    {
        
        return;
    }

   
    if (WIFEXITED(status))               
    {
        child_val = WEXITSTATUS(status); 
        printf("process pid:%d --> exited normally with status %d\n", g_ChildProcessPid,child_val);
    }
}

I have a further question.
I only want to handle the SIG_CHLD generated from the external program i run,maintaining the default behaviour for the SIG_CHLD signals generated from other child processes.So far,the application doesn't fork any other child process,but i can't exclude that in the future someone will add them,so i want these eventual future child processes to be handled in the default way (i.e. being ignored).
Should i change the CallWaitChildProcess function or waitpid will do the job,"excluding" unrecognized pids?