How do I avoid this while printing to screen?

Question

When I do a printk with "bad" characters, sometimes I scrambles my screen,

Is this unavoidable when printing them?

Answer 1

Type reset and Enter on your command line to get it fixed again. If you don't see it anymore, you might have to type it blindly, but it works often. Depending on how you set up your environment, there are characters that can't be printed without messing up your command line.

You can try to print hex values %x. Like this it is usually much easier to find a logic behind the data.