Script to easily create (and destroy) inhibitors for gnome power events

inhibit

#!/usr/bin/env python2
# Creates a new inhibitor
# While this is running the specified events will be inhibited

from optparse import OptionParser
import signal
import dbus
import sys
import os


def get_process_name(pid):
    try:
        f = open("/proc/%d/cmdline" % pid, "r")
        name = f.read()
        f.close()
    except IOError:
        name = ""
    else:
        name = name.replace('\x00', ' ')
    return name

EVENTS = {
    "LOGOUT": 1,
    "USERSWITCH": 2,
    "SUSPEND": 4,
    "IDLE": 8,
}

usage = "%prog [options] <event(s)>"
description = "Creates a new inhibitor. While this is running the specified events will be inhibited."
epilog = "Valid events are %s" % ", ".join(EVENTS.keys())
parser = OptionParser(usage=usage, description=description, epilog=epilog)
parser.add_option("-n", "--name", dest="name", default=get_process_name(os.getppid()),
                  help="name of application that is creating the inhibitor")
parser.add_option("-r", "--reason", dest="reason", default="no reason given",
                  help="reason for inhibiting")
parser.add_option("-f", "--fork", action="store_true", dest="fork", default=False,
                  help="fork this process and print its pid")
parser.add_option("-q", "--quiet", action="store_false", dest="verbose", default=True,
                  help="only print essential information to stdout")
parser.add_option("-s", "--silent", action="store_true", dest="silent", default=False,
                  help="don't print anything to stdout")
(options, args) = parser.parse_args()

if len(args) == 0:
    parser.print_help()
    sys.exit(1)

# Convert the events to a single int
events = 0
for arg in args:
    event = arg.upper()
    if event in EVENTS:
        events |= EVENTS[event]
    else:
        parser.error("'%s' is not a valid event! %s" % (event, epilog))

# Get the SessionManager D-Bus object
bus = dbus.SessionBus()
session_manager = dbus.Interface(
    bus.get_object('org.gnome.SessionManager', '/org/gnome/SessionManager'),
    dbus_interface='org.gnome.SessionManager'
)

# Create args for the inhibitor
# Arg names match the D-Bus API
app_id = dbus.String(options.name)
toplevel_xid = dbus.UInt32(0)
reason = dbus.String(options.reason)
flags = dbus.UInt32(events)

# Fork if necessary
pid = os.fork() if options.fork else os.getpid()

if not options.fork or pid == 0:
    # Create the inhibitor
    session_manager.Inhibit(app_id, toplevel_xid, reason, flags)

if not options.silent and pid != 0:
    if options.verbose:
        print("Created inhibitor (app_id={}, toplevel_xid={}, reason={}, flags={})".format(
            app_id, toplevel_xid, reason, flags))
        msg = "Kill {} to destroy the inhibitor..."
    else:
        msg = "{}"
    if not options.fork:
        msg = "Ctrl-C or kill {} to destroy the inhibitor..."
    print(msg.format(pid))

# Block until we get sent a signal or a keyboard interrupt
# We have to do this otherwise the inhibitor we just created above would be immediately destroyed
# This also the reason why dbus-send doesn't work
if not options.fork or pid == 0:
    try:
        signal.pause()
    except KeyboardInterrupt:
        pass