forum.vdsworld.com

[DavidR]

I've learned a great deal about CGI programming by reading the Posts here but there's one thing I've not quite figured out. Here goes!
My main page runs report.exe on the server that kicks off a rather complex report. Since it may take a while to finish the report I return a message to the user asking them to wait. This page calls a "check.exe" program every 5 seconds that looks for the reports "output" file. If it finds the file it returns it to the user, otherwise it does nothing and the wait page checks again in 5 seconds. So far so good!
Only one iteration of the report can run at a time so when the report starts (the report is a non VDS program) I write a flag file so other users attempting to run the report will get a message telling them that someone else is accessing the report system, try later. The flag file gets deleted by the check.exe program when it returns the report results to the user.
The problem happens when the user gets tired of waiting and closes the browser before the report is finished. The check.exe doesn't run and the flag file stays in place preventing other users from running the report.
Here is the question. Is there any way for a CGI program to detect that the user has closed their browser? Or perhaps there's a better way to approach this.
Anybody have any ideas?

[PGWARE]

Its been awhile since I've used a windows server and created vds cgi's so I'll try to be as helpful as possible

When the report runs it creates a file that contains a flag that basically says a report is in progress thus no one else can load/view the reports until the user logged in is done.

Now the check.exe obviously is no longer executed every 5 seconds thanks to the person closing the browser, thus the flag file remains and never is deleted and in the process makes it appear to all other users checkign teh reports that someone is still logged in trying to run a report.

Now what you can do is if you have a rough idea of how long reports should run for your cgi can first (during login) check the date/time stamp of when the flag file was created. If for instances it more than 5 minutes ago then the report should have finished by then and the cgi script should delete the flag file and allow the new user access.

Not the best solution but one that can be added in with little coding I suspect since it only requires datetime checking during the login phase and checking against the flag file and it's creation date/time.

[Skit3000]

You can also check if the VDS CGI file is still running by using a hidden window. If there isn't a hidden window with the title you specify, but the flag file is still there, you know the client closed his browser window. Here's a rough idea...

[Garrett]

Depending on the kind of access to the server you have, I used to log the
IP address and keep tabs of the current IP's visiting the server. If the IP
dropped off from the server itself, then I would kill the process and clean
up after the visitor and have it ready for the next.

-Garrett

[DavidR]

Thanks for the great responses!
I think I'm going to go with the timer idea since it requires the least amount of re-coding at this point.
Yes I can determine the maximum time for the largest report and put a "timeout" timer in my initial "report.exe" to compare file creation time with current time and delete the flag file if some user "bails out"
Thanks again, I knew somebody would have a solution
...........David

[DavidR]

Is there a "better" way to do this?
It works but it seems like I must be overlooking an easier way.

[jules]

I'd go for:

[DavidR]