. actual text on the screen. In addition, there seem to be somany commands.*These days, the term Unix includes both commercial systems derived from the original Unix code base,and Unix work-alikes. file] The tildes (~) down the lefthand column of the screen indicate that there is no text in the file, not even blank lines. The prompt line (also called the status line) at the bottomof the. the same kind of actions (clear the screen, move the cursor, etc.), but the commands needed to make them do these actions wereA Brief Historical Perspective | 5different. In addition, the Unix...