2. The program expects a filename to be passed as an argument. This file is what it will use to store

the data just before the program is shutdown. The program itself would be invoked the following manner.

All commands / input data are then typed into the standard input of the program. The program loops,

reading these commands and inputs one after the other until it finds an END command. (similar in concept to

mini4).

If the program is not passed the exact number of arguments it needs to work with, then it should display a

message to the standard error and terminate with code 1. For example,