OT What does RET (Enter) do and how does it do it ??

[Alan Cox]

> For 1) How does the context (i.e. that I am in a text program) get
> established?  Is there a context line at the start of the application?
> Is it through main(argc, argv) or some such, depending on the
> programming language of the application?  How does it know to move one
> line down on the screen i.e. is there a system call, a special
> function ?

man termios will teach you more than you ever want to know.