Create a directory named ``pup2'' under your home directory.
This directory must contain
- Makefile
- other files ...
When type ``make'' in your exercise directory, an executable named ``proctree'' must be generated.
Due day, 3/19 00:01am
Your program should accept an argument from commmand line which denotes the level of your fully binary tree. With input 1, only a process is created. (no fork() needed in this case). With input 2, 3 processes is created. With input 3, 7 processes is created. Each process will print its pid and its ppid. And the messages of processes are printed in PRE-order. Example:
```
$ ./proctree 1
pid=25972, ppid=25870
$ ./proctree 2
pid=25975, ppid=25870
pid=25976, ppid=25975
pid=25979, ppid=25975
$ ./proctree 3        (The pid of the shell is 25870.)
pid=25982, ppid=25870
pid=25983, ppid=25982
pid=25984, ppid=25983
pid=25987, ppid=25983
pid=25990, ppid=25982
pid=25991, ppid=25990
pid=25994, ppid=25990
$ 
     
```