Set and clear bits in a bash script

[Ralf Mardorf <ralf.mardorf@alice-dsl.net>]

Hi,

is there a way to set and clear bits of a byte in a bash script, by
using "or" and "and" or has this to be done by an annoying workaround?

I don't find an answer, when I search the Internet.

Regards,
Ralf