Unix-like operating systems famously use the fork system call for creating a new process. The way this system call works in the user code can be quite bewildering when you first learn about it. It creates a child process which is a copy of the parent (with few internal differences), when the system call returns back into user space, you may either be inside the child process or the parent, and you need to check the return value of fork to determine that. A typical example of using fork is shown ...