Exercise 1.1 - Modify the echo program to also print os.Args[0], the name of the command that invoked it.

Exercise 1.12: Modify the Lissajous server to read parameter values from the URL.

Exercise 1.2 - Modify the echo program to print the index and value of each of its arguments, one per line.

Exercise 1.4 - Modify dup2 to print the names of all files in which each duplicated line occurs.