Modify document by vitual printer

README.md

Modify document by vitual printer

Modify document when printing in Windows by create virtual printer

virtual-printer.py

import subprocess
import socket
import select

# pywin32 extension
import win32print
import pywintypes

HOST = '127.0.0.1' # Standard loopback interface address (localhost)
PORT = 8888 # Port to listen on (non-privileged ports are > 1023)
PRINTER_NAME = 'Virtual Printer'

def create_port_printer(host: str, port: int):
    '''Register tcp port for printer, using `cscript prnport.vbs`'''
    create_port_cmd = 'cscript c:\\Windows\\System32\\Printing_Admin_Scripts\\en-US\\prnport.vbs -a -r {ip}:{port} -h {ip} -o raw -n {port}'
    subprocess.check_output(create_port_cmd.format(ip=host, port=port), shell=True)

def create_printer(printer_name: str, host: str, port: int, driver_name='Microsoft Software Printer Driver') -> object:
    '''Create a new printer, if exist return it'''

    try:
        return win32print.OpenPrinter(printer_name)
    except pywintypes.error as e:
        pass

    printer_info = {
        'pPrinterName': printer_name,
        'pDevMode': pywintypes.DEVMODEType(),
        'pDriverName': driver_name,
        'pPortName': f'{host}:{port}',
        'pPrintProcessor': 'WinPrint',
        'Attributes': 0,
        'AveragePPM': 0,
        'cJobs': 0,
        'DefaultPriority': 0,
        'Priority': 0,
        'StartTime': 0,
        'Status': 0,
        'UntilTime': 0,
        'pComment': '',
        'pLocation': '',
        'pDatatype': None,
        'pParameters': None,
        'pSecurityDescriptor': None,
        'pSepFile': None,
        'pServerName': None,
        'pShareName': None
    }

    h_printer = win32print.AddPrinter(None, 2, printer_info)
    return h_printer

def send_to_printer(raw_data: bytes, printer='Microsoft Print to PDF', out_file='out_file'):
    '''Send XPS data to printer'''
    hPrinter = win32print.OpenPrinter(printer)
    try:
        hJob = win32print.StartDocPrinter(hPrinter, 1, (out_file, None, "RAW"))
        try:
            win32print.StartPagePrinter(hPrinter)
            win32print.WritePrinter(hPrinter, raw_data)
            win32print.EndPagePrinter(hPrinter)
        finally:
            win32print.EndDocPrinter(hPrinter)
    finally:
        win32print.ClosePrinter(hPrinter)


def run_server(host: str, port: int):
    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as server_socket:
        server_socket.bind((host, port))
        server_socket.listen()
        print("Listening ...")

        try:
            while True:
                readable, _, _ = select.select([server_socket], [], [], 1)

                for s in readable:
                    raw = b''

                    client_socket, address = s.accept()
                    print('Connected by', address)
                    while True:
                        data = client_socket.recv(1024)
                        if data:
                            raw += data
                        else:
                            client_socket.close()
                            break

                    # Modify data
                    xps_bytes = raw

                    # Reprint it
                    send_to_printer(xps_bytes)
        except KeyboardInterrupt:
            print('Closing ...')

if __name__ == "__main__":
    create_port_printer(HOST, PORT)
    create_printer(PRINTER_NAME, HOST, PORT)
    run_server(HOST, PORT)