Backend not detects USB printer

[Michael Sweet]

shermin wrote:
> Hi,
> I am developing my custom backend for my card printer.My printer will
> respond to usb mass storage cmd structures.So in printer driver with cups i have seen all the commands are send using printf.
> So my question is if i send cmd using printf it will work or i have to handle those in my backend.

printf sends the output to the standard output file descriptor (1).
Since the card printer isn't using a character device, you'll need
to write a backend that reads print data from stdin and writes it to
the printer.

The normal CUPS filter chain looks like this:

     CUPS filters -> your raster filter -> backend

Your raster filter can convert the bitmap data produced by the
upstream filters into commands the printer understands, and then
the backend sends it to the printer.  You just need to write a
backend to communicate with the printer as a mass-storage device
(which means you might just need to mount the card printer and
write a file there?)

-- 
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Michael Sweet, Easy Software Products           mike at easysw dot com