Added tznever sample
diff --git a/samples/tz/README b/samples/tz/README
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index 0000000..ecee023
--- /dev/null
+++ b/samples/tz/README
@@ -0,0 +1,33 @@
+This is an example program that can run as a power
+management hook to set the timezone on the computer
+based on the user's location, as determined by Google
+Latitude. To use this application you will need Google
+Latitude running on a mobile device.
+
+Installation
+============
+ The google-api-python-client library will need to
+be installed.
+
+$ sudo python setup.py install
+
+Then you will need to install the tznever application:
+
+$ sudo cp tznever /usr/sbin/tznever
+
+And then add it in as a power management hook:
+
+$ sudo ln -s /usr/sbin/tznever /etc/pm/sleep.d/45tznever
+
+Once that is done you need to run tznever once from the
+the command line to tie it to your Latitude account:
+
+$ sudo tznever
+
+After that, every time your laptop resumes it will
+check you Latitude location and set the timezone
+accordingly.
+
+TODO
+====
+1. What about stale Latitude data?
diff --git a/samples/tz/tznever b/samples/tz/tznever
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+++ b/samples/tz/tznever
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+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2010 Google Inc. All Rights Reserved.
+# Portions copyright PSF License
+# http://code.activestate.com/recipes/278731-creating-a-daemon-the-python-way/
+
+"""A pm-action hook for setting timezone.
+
+Uses the Google Latitude API and the geonames.org
+API to find your cellphones latitude and longitude
+and from the determine the timezone you are in,
+and then sets the computer's timezone to that.
+"""
+
+__author__ = 'jcgregorio@google.com (Joe Gregorio)'
+
+
+from apiclient.discovery import build
+
+import httplib2
+import os
+import pickle
+import pprint
+import subprocess
+import sys
+import time
+import uritemplate
+
+from apiclient.anyjson import simplejson
+from apiclient.discovery import build
+from apiclient.oauth import FlowThreeLegged
+from apiclient.ext.authtools import run
+from apiclient.ext.file import Storage
+
+# Uncomment to get detailed logging
+# httplib2.debuglevel = 4
+
+# URI Template to convert latitude and longitude into a timezone
+GEONAMES = 'http://api.geonames.org/timezoneJSON?lat={lat}&lng={long}&username=jcgregorio'
+PID_FILE = '/var/lock/tznever.pid'
+CACHE = '/var/local/tznever/.cache'
+
+# Default daemon parameters.
+# File mode creation mask of the daemon.
+UMASK = 0
+
+# Default working directory for the daemon.
+WORKDIR = "/"
+
+# Default maximum for the number of available file descriptors.
+MAXFD = 1024
+
+# The standard I/O file descriptors are redirected to /dev/null by default.
+if (hasattr(os, "devnull")):
+ REDIRECT_TO = os.devnull
+else:
+ REDIRECT_TO = "/dev/null"
+
+
+def main():
+ storage = Storage('/var/local/tznever/latitude_credentials.dat')
+ credentials = storage.get()
+ if len(sys.argv) == 1:
+ if credentials is None or credentials.invalid == True:
+ auth_discovery = build('latitude', 'v1').auth_discovery()
+ flow = FlowThreeLegged(auth_discovery,
+ consumer_key='m-buzz.appspot.com',
+ consumer_secret='NQEHb4eU6GkjjFGe1MD5W6IC',
+ user_agent='tz-never/1.0',
+ domain='m-buzz.appspot.com',
+ scope='https://www.googleapis.com/auth/latitude',
+ xoauth_displayname='TZ Never Again',
+ location='current',
+ granularity='city'
+ )
+
+ credentials = run(flow, storage)
+ else:
+ print "You are already authorized"
+ else:
+ if credentials is None or credentials.invalid == True:
+ print "This app, tznever, is not authorized. Run from the command-line to re-authorize."
+ os.exit(1)
+
+ if len(sys.argv) > 1 and sys.argv[1] in ['hibernate', 'suspend']:
+ print "Hibernating"
+ # Kill off the possibly still running process by its pid
+ if os.path.isfile(PID_FILE):
+ f = file(PID_FILE, 'r')
+ pid = f.read()
+ f.close()
+ cmdline = ['/bin/kill', '-2', pid]
+ subprocess.Popen(cmdline)
+ os.unlink(PID_FILE)
+ elif len(sys.argv) > 1 and sys.argv[1] in ['thaw', 'resume']:
+ print "Resuming"
+ # write our pid out
+ f = file(PID_FILE, 'w')
+ f.write(str(os.getpid()))
+ f.close()
+
+ success = False
+ first_time = True
+ while not success:
+ try:
+ if not first_time:
+ time.sleep(5)
+ else:
+ first_time = False
+ print "Daemonizing so as not to gum up the works."
+ createDaemon()
+ # rewrite the PID file with our new PID
+ f = file(PID_FILE, 'w')
+ f.write(str(os.getpid()))
+ f.close()
+ http = httplib2.Http(CACHE)
+ http = credentials.authorize(http)
+
+ service = build('latitude', 'v1', http=http)
+
+ location = service.currentLocation().get(granularity='city').execute()
+ position = {
+ 'lat': str(location['latitude']),
+ 'long': str(location['longitude'])
+ }
+ http2 = httplib2.Http(CACHE)
+ resp, content = http2.request(uritemplate.expand(GEONAMES, position))
+ geodata = simplejson.loads(content)
+ tz = geodata['timezoneId']
+ f = file('/etc/timezone', 'w')
+ f.write(tz)
+ f.close()
+ cmdline = 'dpkg-reconfigure -f noninteractive tzdata'.split(' ')
+ subprocess.Popen(cmdline)
+ success = True
+ except httplib2.ServerNotFoundError, e:
+ print "still not connected, sleeping"
+ except KeyboardInterrupt, e:
+ if os.path.isfile(PID_FILE):
+ os.unlink(PID_FILE)
+ success = True
+ # clean up pid file
+ if os.path.isfile(PID_FILE):
+ os.unlink(PID_FILE)
+
+
+def createDaemon():
+ """Detach a process from the controlling terminal and run it in the
+ background as a daemon.
+ """
+
+ try:
+ # Fork a child process so the parent can exit. This returns control to
+ # the command-line or shell. It also guarantees that the child will not
+ # be a process group leader, since the child receives a new process ID
+ # and inherits the parent's process group ID. This step is required
+ # to insure that the next call to os.setsid is successful.
+ pid = os.fork()
+ except OSError, e:
+ raise Exception, "%s [%d]" % (e.strerror, e.errno)
+
+ if (pid == 0): # The first child.
+ # To become the session leader of this new session and the process group
+ # leader of the new process group, we call os.setsid(). The process is
+ # also guaranteed not to have a controlling terminal.
+ os.setsid()
+
+ # Is ignoring SIGHUP necessary?
+ #
+ # It's often suggested that the SIGHUP signal should be ignored before
+ # the second fork to avoid premature termination of the process. The
+ # reason is that when the first child terminates, all processes, e.g.
+ # the second child, in the orphaned group will be sent a SIGHUP.
+ #
+ # "However, as part of the session management system, there are exactly
+ # two cases where SIGHUP is sent on the death of a process:
+ #
+ # 1) When the process that dies is the session leader of a session that
+ # is attached to a terminal device, SIGHUP is sent to all processes
+ # in the foreground process group of that terminal device.
+ # 2) When the death of a process causes a process group to become
+ # orphaned, and one or more processes in the orphaned group are
+ # stopped, then SIGHUP and SIGCONT are sent to all members of the
+ # orphaned group." [2]
+ #
+ # The first case can be ignored since the child is guaranteed not to have
+ # a controlling terminal. The second case isn't so easy to dismiss.
+ # The process group is orphaned when the first child terminates and
+ # POSIX.1 requires that every STOPPED process in an orphaned process
+ # group be sent a SIGHUP signal followed by a SIGCONT signal. Since the
+ # second child is not STOPPED though, we can safely forego ignoring the
+ # SIGHUP signal. In any case, there are no ill-effects if it is ignored.
+ #
+ # import signal # Set handlers for asynchronous events.
+ # signal.signal(signal.SIGHUP, signal.SIG_IGN)
+
+ try:
+ # Fork a second child and exit immediately to prevent zombies. This
+ # causes the second child process to be orphaned, making the init
+ # process responsible for its cleanup. And, since the first child is
+ # a session leader without a controlling terminal, it's possible for
+ # it to acquire one by opening a terminal in the future (System V-
+ # based systems). This second fork guarantees that the child is no
+ # longer a session leader, preventing the daemon from ever acquiring
+ # a controlling terminal.
+ pid = os.fork() # Fork a second child.
+ except OSError, e:
+ raise Exception, "%s [%d]" % (e.strerror, e.errno)
+
+ if (pid == 0): # The second child.
+ # Since the current working directory may be a mounted filesystem, we
+ # avoid the issue of not being able to unmount the filesystem at
+ # shutdown time by changing it to the root directory.
+ os.chdir(WORKDIR)
+ # We probably don't want the file mode creation mask inherited from
+ # the parent, so we give the child complete control over permissions.
+ os.umask(UMASK)
+ else:
+ # exit() or _exit()? See below.
+ os._exit(0) # Exit parent (the first child) of the second child.
+ else:
+ # exit() or _exit()?
+ # _exit is like exit(), but it doesn't call any functions registered
+ # with atexit (and on_exit) or any registered signal handlers. It also
+ # closes any open file descriptors. Using exit() may cause all stdio
+ # streams to be flushed twice and any temporary files may be unexpectedly
+ # removed. It's therefore recommended that child branches of a fork()
+ # and the parent branch(es) of a daemon use _exit().
+ os._exit(0) # Exit parent of the first child.
+
+ # Close all open file descriptors. This prevents the child from keeping
+ # open any file descriptors inherited from the parent. There is a variety
+ # of methods to accomplish this task. Three are listed below.
+ #
+ # Try the system configuration variable, SC_OPEN_MAX, to obtain the maximum
+ # number of open file descriptors to close. If it doesn't exists, use
+ # the default value (configurable).
+ #
+ # try:
+ # maxfd = os.sysconf("SC_OPEN_MAX")
+ # except (AttributeError, ValueError):
+ # maxfd = MAXFD
+ #
+ # OR
+ #
+ # if (os.sysconf_names.has_key("SC_OPEN_MAX")):
+ # maxfd = os.sysconf("SC_OPEN_MAX")
+ # else:
+ # maxfd = MAXFD
+ #
+ # OR
+ #
+ # Use the getrlimit method to retrieve the maximum file descriptor number
+ # that can be opened by this process. If there is not limit on the
+ # resource, use the default value.
+ #
+ import resource # Resource usage information.
+ maxfd = resource.getrlimit(resource.RLIMIT_NOFILE)[1]
+ if (maxfd == resource.RLIM_INFINITY):
+ maxfd = MAXFD
+
+ # Iterate through and close all file descriptors.
+ for fd in range(0, maxfd):
+ try:
+ os.close(fd)
+ except OSError: # ERROR, fd wasn't open to begin with (ignored)
+ pass
+
+ # Redirect the standard I/O file descriptors to the specified file. Since
+ # the daemon has no controlling terminal, most daemons redirect stdin,
+ # stdout, and stderr to /dev/null. This is done to prevent side-effects
+ # from reads and writes to the standard I/O file descriptors.
+
+ # This call to open is guaranteed to return the lowest file descriptor,
+ # which will be 0 (stdin), since it was closed above.
+ os.open(REDIRECT_TO, os.O_RDWR) # standard input (0)
+
+ # Duplicate standard input to standard output and standard error.
+ os.dup2(0, 1) # standard output (1)
+ os.dup2(0, 2) # standard error (2)
+
+ return(0)
+
+if __name__ == '__main__':
+ main()
+
+
+