0x16. C - Simple Shell Who designed and implemented the original Unix operating system Who wrote the first version of the UNIX shell Who invented the B programming language (the direct predecessor to the C programming language) Who is Ken Thompson How does a shell work What is a pid and a ppid How to manipulate the environment of the current process What is the difference between a function and a system call How to create processes What are the three prototypes of main How does the shell use the PATH to find the programs How to execute another program with the execve system call How to suspend the execution of a process until one of its children terminates What is EOF / “end-of-file”?