Question

I see console apps print colors and seen apps such as ffmpeg print text over itself instead of a new line. How do I print over an existing line? I want to display fps in my console app either at the very top or very bottom and have regular printfs go there and scroll normally.

I need this for windows, but this is meant to be cross platform, so I will eventually have a linux and mac implementation.

Answer 1

There is two simple possibilities which work on linux as well as windows, but only for one line:

• printf('\b'); will return for one character, so you might count how many character you want to backspace and fire this in a loop, or you know that you only write n numbers and do it like
  printf('\b\b\b\b\b\b\b\b\b\b');
• printf('text to be overwritten by next printf\r'); this will return the cursor to the beginning of the line, so any next printf will overwrite it. Make sure to write a string of same length or longer so you overwrite it entirely.

If you want to rewrite several lines, there is nothing so portable as ncurses, there is libs for it on practically every operating system, and you don’t have to take care of the ANSI-differences.

edit: added link to ncurses wikipedia page, gives great overview and introduction, as well as link list and maybe a translation to your preferred language