7. [2] When we call a system call such as fork in C, we do so with what looks like a C function call. Are we really making a function call? 8. [2] What does parse_args() do? Specifically, what is its input, and 9. [1] Why does interaction with 3000shell often gets "messed up" when 10. [2] What system calls are used to list all the files in a directory? What Explain. what is its output and side effects? running programs in the background with &? are the library calls that are normally used to make those system calls? 11. [1] What happens when you delete line 293 (the call to wait())? Why? 12. [2] What happens to an in-progress system call when a process receives a signal? (An example is a program waiting for input from a terminal with a blocking read call.) What does "restarting" a system call have to do with this? 13. [2] Describe how you could add input redirection for external programs to 3000shell