I have googled for this topic but cannot seem to find anything
useful.  I want to print a few things directly from an irb session to
one of a number of networked printers that I have configured with
CUPS.

$ lpstat -v
device for HPLj5N: socket://168.192.1.49:9100
device for NP4172: lpd://168.192.1.52/NP4172
device for NP4173: lpd://168.192.1.53/NP4173
device for NP4174: lpd://168.192.1.54/NP4174

For example:

>> my_lp = File.open("????","w")
>>
>> my_lp.puts(my_array)

What argument string do I use in order to obtain an IO stream to one
of these devices?