Does the cups backend support printers in bidirectional mode?

[Michael Sweet]

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.

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______________________________________________________________________
Michael Sweet, Easy Software Products           mike at easysw dot com
Internet Printing and Publishing Software        http://www.easysw.com