terminal program - how to update onscreen data?

this is kind of weird question but i don't know how it's called.

Basically there is a console-based (Linux) program which outputs some data (lines) to stdout and then it only changes the values of the data which are already on screen. I only kno开发者_如何学Gow how to output a line of text, but it can never be changed after flushing. How can be this done? How to for example make ASCII table (table made of ASCII characters) and only change values in this table? thanks

You should check into the curses/ncurses libraries.

Here's some reading: http://www.faqs.org/docs/Linux-HOWTO/NCURSES-Programming-HOWTO.html