[yellowapple]

> So, if I plug a USB printer into a computer, and ls > /dev/usbXXX, will it print today? Does that still "just work"?

I can't attest to whether piping directly to the device works, but I routinely do stuff like

    lpr -o raw -P $SOME_CUPS_PRINTER < $SOME_FILE

Back when I was doing warehouse IT work I'd hand-write ZPL code and shove it directly into Zebra printers for things like asset tags, printed instructions on equipment, etc. This was also my approach for various tools I wrote to automate the printing of packing slips and shipping labels - except these programs had to run on Windows machines, and I tell ya hwat Windows sure doesn't make it as easy as CUPS does.

More recently I dusted off that particular skillset in order to print a bunch of labels for my kitchen. ZPL really ain't that bad of a language; sure beats trying to write PostScript or PCL by hand :)