Reading characters from stdin

[Rena <hyperhacker@...>]

(Yep, this question again. :p)

I'm coding in a rather limited Linux-like environment: I have a text editor, a terminal emulator, a Lua 5.1 interpreter, and not much else. I don't have a C compiler.

My problem is I want to read keys from stdin as soon as they're pressed, without having to press enter. The only ways I know to do this involve C function calls. Is there perhaps an ANSI escape code or some other crazy trick I can use? Can I call some program with os.execute to change terminal settings?