2023-08-16 23:46:20 +02:00

79 lines
2.3 KiB
Python

#!/usr/bin/python
# -*- coding: utf-8 -*-
"""This module contains the implementation of the CupsPrinter printer driver.
:author: python-escpos developers
:organization: `python-escpos <https://github.com/python-escpos>`_
:copyright: Copyright (c) 2012-2023 Bashlinux and python-escpos
:license: MIT
"""
from ..escpos import Escpos
import os
import sys
import subprocess
if not sys.platform.startswith("win"):
class LP(Escpos):
"""Simple UNIX lp command raw printing.
Thanks to `Oyami-Srk comment <https://github.com/python-escpos/python-escpos/pull/348#issuecomment-549558316>`_.
inheritance:
.. inheritance-diagram:: escpos.printer.LP
:parts: 1
"""
def __init__(self, printer_name: str, *args, **kwargs):
"""LP class constructor.
:param printer_name: CUPS printer name (Optional)
:type printer_name: str
:param auto_flush: Automatic flush after every _raw() (Optional)
:type auto_flush: bool
"""
Escpos.__init__(self, *args, **kwargs)
self.printer_name = printer_name
self.auto_flush = kwargs.get("auto_flush", True)
self.open()
def open(self):
"""Invoke _lp_ in a new subprocess and wait for commands."""
self.lp = subprocess.Popen(
["lp", "-d", self.printer_name, "-o", "raw"],
stdin=subprocess.PIPE,
stdout=open(os.devnull, "w"),
)
def close(self):
"""Stop the subprocess."""
self.lp.terminate()
def flush(self):
"""End line and wait for new commands."""
if self.lp.stdin.writable():
self.lp.stdin.write(b"\n")
if self.lp.stdin.closed is False:
self.lp.stdin.close()
self.lp.wait()
self.open()
def _raw(self, msg):
"""Write raw command(s) to the printer.
:param msg: arbitrary code to be printed
:type msg: bytes
"""
if self.lp.stdin.writable():
self.lp.stdin.write(msg)
else:
raise Exception("Not a valid pipe for lp process")
if self.auto_flush:
self.flush()