Does the cups backend support printers in bidirectional mode?

[Yu Guo]

> Yu Guo wrote:
> > Does the cups backend support printers which could working in bidirectional mode?
>
> Yes.
>
> > How can I get data sending by the printer if I use the cups serial or usb backends, in order to pass the working state of the printer back to the filter or the user application?
>
> Use the cupsBackChannelRead() function in the CUPS API, or read from
> file descriptor 3.
>
> --

That helps! Thank you very much!