Hi all.. I've got a USB barcode scanner, and I'ld like to have a script
running in the background the listens to input received from it.

That seems simple enough, except that as soon as I plug it in, it gets
recognised as a USB keyboard device (which it is, so no surprise there),
and gets added to the devices that send their input to the console.

In other words, if I scan a barcode with it, the digits get entered on
the console just as if I had typed them on the connected PS/2 keyboard.

I suspect this is by design, so that connecting another keyboard or
mouse just 'works', but what I want to do is have that device talking
exclusively to a script that handles the input.

I was hoping it would be as easy as opening say /dev/ttyUSB0, but that
doesn't appear to be the case.