input_filter

/usr/local/bin/gs -dSAFER -dNOPAUSE -q -sDEVICE=ljet4 -sOutputFile=- /home/kubicek/margin.ps - | /usr/local/libexec/tray_select.rb -L

print.sh

source_pdf=$1
pages_count=`pdftk $source_pdf dump_data | grep NumberOfPages | awk '{print $2}'`

echo "Processing $pages_count pages"

if test $pages_count -eq 1
then
  echo "Printing first page"
  cat $source_pdf | lpr -Pir1022_lower_tray
fi

if test $pages_count -gt 1
then
  echo "Printing first two pages"
  pdftk $source_pdf cat 1-2 output - | lpr -Pir1022_lower_tray
fi

if test $pages_count -gt 2
then 
  echo "should print some pages on white paper"
  echo "printing aditional pages" 
  pdftk $source_pdf cat 3-end output - | lpr -Pir1022_upper_tray
fi

tray_select.rb

#!/usr/local/bin/ruby

data = $stdin.read
case ARGV[0]
   when "-L": print "\e&l4H" # Lower
   when "-U": print "\e&l1H" # Upper
   else print "\e&l2H" # Manual
end
print "\e&l1S" # DUPLEX
puts data[2..-1]