scheduler.py : simulate cron

[karxx]

Hi Gurus,

Making my first python program and try to mimic a crontab.

running : 2.6 with sched module

I need to create a python program which can execute programs at a specific time. so I have a list of schedule such as

[Start_Time], [Action]
Monday 25th September 2009 10:00:00, /opt/prgr/run1.sh
Monday 25th September 2009 11:00:00, /opt/prgr/run2.sh
Monday 25th September 2009 12:00:00, /opt/prgr/run3.sh
...

so based on python sched doc I create something simple just to understand the concept:

import time 
import sched 
def timedAction(arg1): 
     print arg1
     print time.time() 
 
s = sched.scheduler(time.time, time.sleep) 
startTime = time.mktime(time.strptime("Aug 29 18:25 2007", '%b %d %H:%M %Y')) 
timer1 = s.enterabs(startTime, 0, timedAction, ("Hello world 1",)) 
print "start1:" + str(startTime)
startTime = time.mktime(time.strptime("Aug 29 18:35 2007", '%b %d %H:%M %Y'))
print "start2:" + str(startTime) 
timer1 = s.enterabs(startTime, 0, timedAction, ("Hello world 2",)) 
s.run() 

The result is the following:
start1:1188404700.0
start2:1188405300.0
Hello world 1
1251289489.67
Hello world 2
1251289489.67

My understanding is the timedAction function should be executed at:
start1:1188404700.0
start2:1188405300.0
and not at 1251289489.67 which seems to be the case.

I guess I misunderstood to objective and usage of this module. Please could you help here ? I'd like to ensure that the function timedaction start at the right time. By the way, how does sched work from the theorical standpoint. the script is executed and finshed right away but I do not see any deamon running to execture called function. I miss some concept here...

Thanks for your lights

KarXX

[bvdet]

Your date of "Aug 29 18:25 2007" is long passed, so the scheduler immediately executed the code. Try setting startTime to some future time.

[karxx]

thanks bvdet, looks better.I will test the same with threading now ...

btw, I noticed that job is finishing after the last events processing. Now how can I instument the script to act as a daemon. I'd like to get the script running forever until schedule list changes but on the other I want to get this list of schedule reloaded everyday. can I do something like :
...
s.run()
while(1):
if newday then
purge queue
load_schedule

cheers

[bvdet]

I have never done anything like this before. I would think it would be best to schedule the python script to run every day through the OS, but don't see any reason the script could not run continuously. If you want it to run forever, use time.sleep() to get the script to pause to avoid consuming your processor. You can use while True:, but I would build in a means of stopping it if certain conditions are met - possibly check a configuration file every so often.

[karxx]

cannot have the OS instrumenting this, so it should really act as a daemon.
I will test it right away. cheers

[bvdet]

I don't know how to initiate a daemon. Perhaps you can post back the results of your testing.