klipper-dgus/klippy/util.py

39 lines
1.1 KiB
Python

# Low level unix utility functions
#
# Copyright (C) 2016 Kevin O'Connor <kevin@koconnor.net>
#
# This file may be distributed under the terms of the GNU GPLv3 license.
import os, pty, fcntl, termios, signal
# Return the SIGINT interrupt handler back to the OS default
def fix_sigint():
signal.signal(signal.SIGINT, signal.SIG_DFL)
fix_sigint()
# Set a file-descriptor as non-blocking
def set_nonblock(fd):
fcntl.fcntl(fd, fcntl.F_SETFL
, fcntl.fcntl(fd, fcntl.F_GETFL) | os.O_NONBLOCK)
# Clear HUPCL flag
def clear_hupcl(fd):
attrs = termios.tcgetattr(fd)
attrs[2] = attrs[2] & ~termios.HUPCL
termios.tcsetattr(fd, termios.TCSADRAIN, attrs)
# Support for creating a pseudo-tty for emulating a serial port
def create_pty(ptyname):
mfd, sfd = pty.openpty()
try:
os.unlink(ptyname)
except os.error:
pass
os.symlink(os.ttyname(sfd), ptyname)
fcntl.fcntl(mfd, fcntl.F_SETFL
, fcntl.fcntl(mfd, fcntl.F_GETFL) | os.O_NONBLOCK)
old = termios.tcgetattr(mfd)
old[3] = old[3] & ~termios.ECHO
termios.tcsetattr(mfd, termios.TCSADRAIN, old)
return mfd