John, I've used option #1 as a more simplistic approach to this type of thing. To avoid the problem you mentioned, I use an OS semaphore to indicate that the program is running. It sets the semaphore, pauses, then checks that it has the only semaphore set. If so, it continues. If not, execution ends. I got this code from a Fox Talk issue. Pretty handy - even ported it to VBA for my Access apps. It lets me control whether or not I want multiple instances of an application running on a station, alerting the user, and switching to the already running instance if only one instance is allowed.
I then use the MS scheduler to launch the app. This allows the app to be launched on a schedule or manually if need be with different command line arguments. Drawback of course is that your continually starting/stopping the app so there is some overhead there. Of course it also wipes the slate clean each time, which on occasion has worked in my favor<g>. Jim. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of John Weller Sent: Monday, December 18, 2006 5:43 PM To: [EMAIL PROTECTED] Subject: Polling App Hi Guys, I have to write a small utility that will check for the presence of a file or files in a particular folder every 5 minutes or so. If any are there it does some processing on them. It will probably run on the server. As I see it there are two ways I can go: 1. Have a program that runs every 5 minutes triggered by scheduler. Snag arises if the processing takes more than 5 minutes (which could possibly happen in the future). 2. Run the program continuously in a loop which will process the files then go to sleep for 5 minutes (using the API Sleep function). Question - will this absorb much in the way of resources? I've found the Fox to be very fast but a resource hog. Any comments or suggestions of a better way will be gratefully received - I see no benefit in re-inventing the wheel if someone has already tried something similar. TIA John Weller 01380 723235 07976 393631 [excessive quoting removed by server] _______________________________________________ Post Messages to: [email protected] Subscription Maintenance: http://leafe.com/mailman/listinfo/profox OT-free version of this list: http://leafe.com/mailman/listinfo/profoxtech ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
