Description:
Like the previous exercise, your program creates a process tree from the argv[1] and argv[2]. The purpose of argv[] is just like exercise 2. Each process when created will print a line to show its label, pid, and ppid. However the order is not specified. In another shell or window, you can send signal to the leaves. When a leaf terminated by a signal, its parent, waiting for children, will know the terminated signal and will print a line. When all children are waited, the internal node process will exit with a value equal to number of nodes in the subtree rooted with that process.
Deadline: 2010 Apr 8 00:05am
Put your file(s) under ~/usp-982/exer3

Examples :

                  shell
                    | 
                    a
                   / \
                  b   e
                 / \   \
                c   d   f
$ ./a.out ddduduudduuu abcdef
I'm c, my pid=9693, and my ppid=9692
I'm d, my pid=9695, and my ppid=9692
I'm f, my pid=9696, and my ppid=9694
I'm e, my pid=9694, and my ppid=9691
I'm b, my pid=9692, and my ppid=9691
I'm a, my pid=9691, and my ppid=9572
child 9693 signaled with signal 1            $ kill -1 9693  # node c
child 9696 signaled with signal 2            $ kill -2 9696  # node f
child 9694 exited with value 2                               # node e exited
child 9695 signaled with signal 3            $ kill -3 9695  # node d
child 9692 exited with value 3                               # node b exited
$ echo $?                                                    # node a exited
6                                                            
$