Description:
Like exercise 3, a process tree is created according to argv[]. Each process when created will print a line to show its label, pid, and ppid. However the order is not specified. A pipe should be created between parent and its child. The parent writes and the child reads. The root process reads from stdin a char and `broadcast' to its children via the pipes. And the char is flowed down to every node. The process with its label equal to the input char will show a message, including its label, the number of times the char received.
Deadline: 2010 Apr 22 00:05am
Put your file(s) under ~/usp-982/exer5

Examples :

                  shell
                    | 
                    a
                   / \
                  b   e
                 / \   \
                c   d   f
$ ./a.out ddduduudduuu abcdef
I'm c, my pid=2760, and my ppid=2759
I'm f, my pid=2762, and my ppid=2761
I'm d, my pid=2763, and my ppid=2759
I'm e, my pid=2761, and my ppid=2758
I'm a, my pid=2758, and my ppid=2460
I'm b, my pid=2759, and my ppid=2758
a                                                <---- from stdin 
hello, i'm a, my pid is 2758, counted 1 times    <---- root answers
a                                                <---- again
hello, i'm a, my pid is 2758, counted 2 times
b                                                <---- from stdin
hello, i'm b, my pid is 2759, counted 1 times    <---- sending via pipe to b
b
hello, i'm b, my pid is 2759, counted 2 times
c
hello, i'm c, my pid is 2760, counted 1 times
e
hello, i'm e, my pid is 2761, counted 1 times
e
hello, i'm e, my pid is 2761, counted 2 times
q                                                <---- exit peacefully
$