pharos

#!/usr/bin/python2
# Script Name: pharos
# Script Function:
#	This is a CUPS backend for the Pharos Remote Printing LPD Server.
# Save this file in your CUPS backend directory, usually
# /usr/lib/cups/backend/ or /usr/local/lib/cups/backend/ or /usr/libexec/cups/backend/
#
# Mark this filter world-readable and world-executable. Restart CUPS to
# make the new backend known to the spooler.
#
# See http://www.openprinting.org/cups-doc.html and the additional
# instructions below.
#
# Usage: 
#
# cp pharos /usr/lib/cups/backend/
# chmod 755 /usr/lib/cups/backend/pharos
# killall -HUP cupsd (or "/etc/init.d/cups restart")
# lpadmin -p <queue name> -E -v pharos://<print server address>/<print queue>
#
# with 
#   <print server address>:     The DNS name or IP address of the print server
#   <print queue>:		The name of the LPD queue on the print server
# Example URIs:
# pharos://printserver.university.edu/HP_LaserJet
# 
#	This will print to a Pharos Uniprint Print server with DNS name printserver.university.edu and print queue HP_LaserJet
#
# Author: Junaid Ali
# Version: 1.0

__version__ = '1.0'
__title__ = 'CUPS backend for Pharos Remote Printing'
__doc__ = 'CUPS backend for popup based printing to Pharos LPD server'

# Imports ============================================
import sys
import os
import socket
import ConfigParser
import os
import logging
import logging.config
import tempfile
import subprocess
import re

# CUPS backend return codes =========================
CUPS_BACKEND_OK = 0
CUPS_BACKEND_FAILED = 1
CUPS_BACKEND_AUTH_REQUIRED = 2
CUPS_BACKEND_HOLD = 3
CUPS_BACKEND_STOP = 4
CUPS_BACKEND_CANCEL = 5

# Script Variables ===================================
programConfigFilePath = '/usr/local/etc/pharos.conf'
cupsBackendDIR = '/usr/lib/cups/backend'

if not os.path.isdir(cupsBackendDIR):
        cupsBackendDIR = '/usr/libexec/cups/backend'

# Function Declaration ===============================
def main():
	"""
	The main function of the script
	"""
	if len(sys.argv) == 1:
		# Without arguments display backend info
		sys.stdout.write("network %s \"Unknown\" \"%s\" \n" %(os.path.basename(sys.argv[0]),  __doc__))
		sys.stdout.flush()
		sys.exit(CUPS_BACKEND_OK)
	if len(sys.argv) not in (6,7):
		sys.stdout.write("Usage: %s job-id user title copies options [file]\n" % os.path.basename(sys.argv[0]))
		sys.stdout.flush()
		logger.error("Wrong number of arguments (%d). Usage %s job-id user" %(len(sys.argv[0]),  sys.argv[0]))
		sys.exit(CUPS_BACKEND_OK)
	
	# Try to get print job parameters from user
	host = ''
	if os.path.exists(programConfigFilePath):
		logger.info('calculating port information using %s' %programConfigFilePath)
		config = ConfigParser.ConfigParser()
		config.read(programConfigFilePath)
		port = config.getint("popupserver", "port")
		logger.info('Setting up the server connection port to %d' %port)
	else:
		port = 50000
	
	logger.info('Trying to connect to host %s on port %d' %(host, port))
	try:
		s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
		s.connect((host, port))
	except socket.error, (value, message):
		if s:
			s.close()
		logger.error('Could not connect to popup server. Error %s' %message)
		sys.exit(CUPS_BACKEND_FAILED)
		
	s.send('GetPrintJobParameters')
	data = s.recv(1024)
	s.close()
	logger.info('Received response = %s' %data)
	# Split response
	responseParts = data.split(',')
	printjobparams = {}
	for part in responseParts:
		peices = part.split(':')
		if len(peices) == 2:
			printjobparams[peices[0].strip()] = peices[1].strip()
	logger.info('Response dictionary = %s' %printjobparams)
		
	logger.info('User ID received = %s' %printjobparams["userid"])
	logger.info('Print Command received = %s' %printjobparams["printjob"])
	
	# Calculate actual LPD queue DEVICE URI
	logger.info('Processing DEVICE_URI')
	deviceURI = os.environ['DEVICE_URI']	
	devParts = deviceURI.split(':')[1].split('/')
	deviceURI = 'lpd://' + devParts[len(devParts)-2] + '/' + devParts[len(devParts)-1]
	logger.info('lpd print queue uri = %s' % deviceURI )
	os.environ['DEVICE_URI'] = deviceURI
	logger.info('Set DEVICE_URI to %s' % os.environ['DEVICE_URI'])

	# Check input arguments
	jobID = sys.argv[1]
	userName = sys.argv[2]
	jobTitle = sys.argv[3]
	copies = sys.argv[4]
	printOptions = sys.argv[5]
	if len(sys.argv) > 6:
		logger.info('using printFile %s' %sys.argv[6])
		printFile = sys.argv[6]
	else:
		# Create print file from STDIN
		logger.info('printFile argument not supplied, will create it using STDIN')
		printFileTuple = tempfile.mkstemp()
		printFile = printFileTuple[1]
		printFileHndl = open(printFile,  'wb')
		for line in sys.stdin:
			printFileHndl.writelines(line)
		printFileHndl.close()

	# check if continue printing
	if not printjobparams["printjob"] == "yes":		
		logger.info("User chose to cancel job. Exiting")
		if os.path.exists(printFile):
			os.unlink(printFile)
		sys.exit(CUPS_BACKEND_CANCEL)

	logger.info('Job Arguments (Job ID: %s, User Name: %s, Job Title: %s, Copies: %s, Print Options: %s, Print File: %s)' %(jobID,  userName,  jobTitle,  copies,  printOptions,  printFile))	
	command = [os.path.join(cupsBackendDIR, 'lpd'), jobID,  printjobparams["userid"],  jobTitle,  copies,  printOptions,  printFile]
	logger.info("Running Command with pipe separated arguments: " + "|".join(command))
	returnCode = subprocess.call(command)
	logger.info('Command return code = %d' %(returnCode))
	
	# Delete the temp file used
	if os.path.exists(printFile):
		os.remove(printFile)
		logger.info('Successfully removed print file: %s' %(printFile))
	
	# Terminate gracefully and return the code from lpd printing
	logger.info('Printing completed')
	sys.exit(returnCode)

# Main Script ========================================
try:
	logging.config.fileConfig(programConfigFilePath)
	logger = logging.getLogger('pharos')	    
except (TypeError, ConfigParser.NoSectionError):
	syslog.syslog(syslog.LOG_ERR, '%s could not instantiate logging using config file %s. Exiting' %(sys.argv[0], programConfigFilePath))
	sys.exit(CUPS_BACKEND_STOP)
if __name__ == "__main__":
	main()