In Python on Unix, determine if I am using my computer? or idle?

I would like to write a script to do an heavy network upload, in the background. However, I would like it to pause when I am using my computer (either by detecting network activity or keyboard activity or that I am not idle).

What is the best way to detect that I am using the computer, on Python on Unix?

Answer

Unixy solution using X11/XScreenSaver to get idle time:

#!/usr/bin/python
import ctypes
import os

class XScreenSaverInfo( ctypes.Structure):
  """ typedef struct { ... } XScreenSaverInfo; """
  _fields_ = [('window',      ctypes.c_ulong), # screen saver window
              ('state',       ctypes.c_int),   # off,on,disabled
              ('kind',        ctypes.c_int),   # blanked,internal,external
              ('since',       ctypes.c_ulong), # milliseconds
              ('idle',        ctypes.c_ulong), # milliseconds
              ('event_mask',  ctypes.c_ulong)] # events

xlib = ctypes.cdll.LoadLibrary('libX11.so')
display = xlib.XOpenDisplay(os.environ['DISPLAY'])
xss = ctypes.cdll.LoadLibrary('libXss.so.1')
xss.XScreenSaverAllocInfo.restype = ctypes.POINTER(XScreenSaverInfo)
xssinfo = xss.XScreenSaverAllocInfo()
xss.XScreenSaverQueryInfo(display, xlib.XDefaultRootWindow(display), xssinfo)

print "idle: %d ms" % xssinfo.contents.idle

# cleanup
xss.XCloseDisplay(display)
xss.XFree(xssinfo)

(From “X11 idle time and focused window in Python”, originally found on thp.io, now apparently only the GitHub gist by the same author survives.)

A cleanup section was added to the code in a later edit by another user so that it can be called periodically.

As noted in a comment to the answer they reference, note that you should also do proper return code checking on function calls to avoid ungraceful program termination when X display and other initializations fail for some reason.