#!/usr/bin/perl -w

################################################################
#
# Welcome to the CUPS PAP backend. A colleague downloaded a 
#  Shell script off the net that was supposed to do all of 
#  this, and it didn't work very well...
#  At all, actually. So I decided to whip up my own in Perl.
#  This is that script. I have done some optimization based on
#  the CUPS "Writing Backends" document as provided w/ version
#  1.1.17.
#
# It works with CUPS 1.1.17 or newer,
#  possibly older, I don't know - as well as any modern 
#  (1.4b2+) version of Netatalk upto and probably surpassing
#  the 1.6.0 release.
#
# This software is to be considered public domain. Do with it as
#  you will.
#
# Written 5/Dec/2002 by Matthew Keller <kellermg@potsdam.edu>
#
################################################################
#
# INSTALLATION (by the aforementioned "colleague")
#
# Requirements: Perl and netatalk.  If you don't know what
#  those are, I think you're in over you're head...
#
# Save this script as /usr/lib/cups/backend/papbackend
#  (....or wherever you have the other backends if you 
#  aren't running a stock install of CUPS). Make sure it is
#  executable!
# Then, make sure the entry for the AppleTalk printer in 
#  /etc/cups/printers.conf is declared with a URI thus:
#
#   DeviceURI papbackend://"Printer Name"@"Some Zone"
#
# THE QUOTES ARE IMPORTANT AND NECESSARY if you have spaces
#  in your Printer Name or your Zone Name.  If you have no
#  zones on your network, then "Printer Name"@* should work.
#
# *NOTE: The URI can also be declared in the CUPS web interface
#  and will get properly entered in printers.conf if you do it
#  that way.  But it gets mangled when viewing printer 
#  properties via the web interface.  This is OK, though I 
#  don't know why CUPS does this!  As long as it's OK in 
#  printers.conf, that's all that matters.
#
# -- 6/Dec/2002 by Romeyn prescott <prescor@potsdam.edu>
#
###############################################################
#
# If there aren't at least 5 arguments, there is a problem. 
#  Tell the user and die.
if(scalar(@ARGV) < 5) {
	die "pap backend is quite unhappy. Mainly because there are only " . scalar(@ARGV) . " elements on the argument list and there should be at least 5.";
}

# Trash or stash variables as desired
shift @ARGV; # We don't care about the job ID
my $user=shift @ARGV; # We don't care about the user either, 
		      # but we'll pretend we do.
shift @ARGV; # We couldn't care less about the title.
my $copies=shift @ARGV; # Number of copies we definitely care about
if($copies < 1) { $copies = 1; } # Sanity check.
shift @ARGV; # Options? Bah!

# Glean the device from the environment and format it
#  The device is is assumed to be a properly formated NBP_NAME 
#  (see man page for nbp_name) for the printer, preceded
#  by CUPs' papbackend:// garbage. Make sure any spaced words
#  are quoted properly, or else pap will die. NO TRAILING SLASHES,
#  ASSHAT!!!!
#  Right:   papbackend://"My Printer"@"My Zone"
#  Wrong:   papbackend://"My Printer"@"My Zone"/
#  Wrong:   papbackend://My Printer@My Zone
#  Wrong:   papbackend://"My Printer@My Zone"
my $device=$ENV{DEVICE_URI};
$device =~ s/^papbackend:\/\///;

# Deal with the file
my $file="";
unless(scalar(@ARGV)) { # Is @ARGV all popped out?
	# File must be on stdin, put it in $file.
	$file="/var/tmp/$$.prn";
	$copies=1; # CUPS want's backends to NOT trust command-line
		   #  copies for STDIN-spooled jobs
	# Open it, write to it, close it, else die
	open(TMF,">$file") or die "Could not write to $file! $!\n";
	print TMF <STDIN>;
	close TMF;
} else {
	# File was spooled to a file, and is supplied.
	$file=shift @ARGV; # The last argument is the filename.
}

# Print it... Many times if necessary.
while($copies > 0) {
	# Send it to the pap program
	`/usr/local/bin/pap -p $device $file`;
	$copies--;
}

# Burn the evidence
unlink $file;