ggr@packard.UUCP (Guy Riddle) (08/11/85)
) Both the 4.2BSD and System V line printer spoolers invoke a ) printer-specific interface program with one file descriptor ) already open to "the device" (the printer). On both systems the ) fd is open for writing, but the documentation states that the ) device can be opened for reading also under certain ) circumstances (specifying "rw" in the BSD printcap entry, or ) having the file (device) readable on SysV); however, you still ) only get one fd when you get called. You do NOT get passed the ) name of the device (so you can't do your own open(2)). On System V the interface script can get the name of the printer by `basename $0` and use it to do an open or set up a network connection or whatever. For our network-attached printers, we just tell lpadmin(1M) that the device to open is /dev/null and the real open (and connect) is done by the programs invoked by the interface script. === Guy Riddle == AT&T Bell Laboratories, New Jersey === ggr.btl@csnet-relay.ARPA ihnp4!ggr