adding a new printer .ppd file

[John]

This isn't a question, just something that I had a bit of trouble with, and couldn't find documented anywhere, so I thought I'd put my solution here for future reference for others....

I was trying to set up CUPS for the first time, using an HP8150DN network printer.  The only ppd files that come with CUPS by default are a generic HP LaserPrinter file, which did not recognize that my 8150 printer was capable of using PostScript - so, I needed to add the actual 8150 ppd file.  I found the file at http://cups.org/ppd.php, and downloaded it, but could not find any documentation indicating where it should go. After looking around a bit, I found the default ones at
    <BASE-DIR>/share/cups/model
so I added my new one there. However, the Web Gui did not "see" it. After thinking a bit more about this, and finding the binary file /etc/cups/ppd.dat, I tried SIGHUP'ing the cupsd process (kill -1), and that apparently forced a re-read of the .../model directory, and updated the /etc/cups/ppd.dat file. After that the new ppd file showed up in the Web Gui (when adding a new printer or modifying ann existing one).

    John