printer daemon (mini-lpd)

mini-lpd is a small, non-queueing lpd implementation. It uses /etc/mini-lpd as its configuration directory. Every directory below is the name of a queue:

[15:09] hydrogenium:~# ls -l /etc/mini-lpd 
total 0
drwx------  2 root root 6 Aug 28 15:09 lp0
drwx------  2 root root 6 Aug 28 15:09 lp1

Those "`objects"' (directories) contain an attribute "`device"', which is where the mini-lpd writes the incoming data to:

[15:10] hydrogenium:~# ls -l /etc/mini-lpd/lp*
/etc/mini-lpd/lp0:
total 0
lrwxrwxrwx  1 root root 9 Aug 28 15:10 device -> /dev/null

/etc/mini-lpd/lp1:
total 0
lrwxrwxrwx  1 root root 8 Aug 28 15:10 device -> /dev/lp0

You could add other attributes like "`filter"' (unsupported currently), which could be a link to a program filtering the input before mini-lpd would write it to the device.