[Help-bash] Finding terminal which currently has focus?

[adrelanos]

Hi,

I know I can use `tty` to find out the the processes own terminal. But
what about the current focus?

One can spawn many login shells tty1, tty2 etc. Can a bash script in
tty1 know, that tty1 is currently not being looked at? Or in other
words, can the bash script in tty1 know that currently lets say tty7 is
visible?

Cheers,
adrelanos