I was trying to print on a Samsung ML-4500, I found a ghostscript driver
as a patch to gs 5.50 on http://www.linuxprinting.org/. I recompiled gs with
the driver and tried to set it up with apsfitler, unfortunately apsfilter
requires that I the driver be selected from a list stored in
/usr/share/apsfilter/setup/, so I had to edit devices-5.50. Would it be
possible to add an option to enter the name of the ghostscript output device
as an alternative to selecting it from a list.

I ran into the same problem after I installed the hpijs package and
wanted to use it in apsfilter. To tell apsfilter to use the DJ8xx driver
which was now available I had to manually edit
/usr/share/apsfilter/setup/printers-6.50

There must be a better way?

Not sure if anybody is still using apsfilter, but he is a patch to fix this
bug that I submitted 25 years ago.

diff --git a/SETUP.in b/SETUP.in
index d8e212a..207c7a8 100755
--- a/SETUP.in
+++ b/SETUP.in
@@ -336,6 +336,7 @@ do_choose_driver()
     14) Lexmark inkjet printer
     15) miscellaneous other drivers
     16) non-printer devices (caution! -- read the handbook)
+    17) enter ghostscript device name manually

     0)  return to main menu

@@ -360,6 +361,18 @@ do_choose_driver()
        14)     PRINTER_LIST=setup/printer-lexmark ;;
        15)     PRINTER_LIST=setup/printer-misc ;;
        16)     PRINTER_LIST=setup/non-printer ;;
+       17)     # manual entry of device name
+               echo
+               echo "Enter the ghostscript device name exactly as shown by 'gs -h'."
+               echo "Use (D) from the main menu to see available devices."
+               echo
+               echo $n "Device name: $c"; read PRINTER
+               if [ -z "$PRINTER" ]; then
+                   do_choose_driver
+                   return
+               fi
+               check_for_gs_support "$PRINTER" || do_choose_driver
+               return ;;
        *)      return ;;
     esac