My office has a color duplex laser printer.
Getting it to print duplex pages and pages in color using LPR was kind of hard. I had to write my own ghostscript command as printer filters for separate simplex and duplex mode (virtual) printers.
Getting it to do the same using CUPS was and still is impossible. Since I don't use x86 Linux, let alone a major distro, I can't use the manufacturer's driver, and compatible drivers are simplex B/W only.
Yet LPR is a relic to leave behind?
@arielmt our experience with cups and fancier printers is that you can usually extract the PPD from the manufacturer and feed it to cups
@atax1a I seriously considered that very thing until going mad from not finding clear answers about how to write my own without hacking someone else's as a potentially poor example.
That's when I realized investing my time in a hand-written LPR filter using clear examples instead was quicker and easier.
@arielmt i feel like the CUPS documentation on this is actually reasonable, but also we are extremely postscript brained so our reasonable is perhaps not globally so https://www.cups.org/doc/ppd-compiler.html
@atax1a I don't know why I couldn't find this when I needed it. Thank you.
@arielmt aiui you ought to be able to start from the generic color PPD and add the duplexing by cribbing off of the feature declaration in the manufacturer PPD
@arielmt rip :( that might drive us into "writing our own PPD" territory if we were encountering it