Creating a background task from the web

andy_7t has asked for the wisdom of the Perl Monks concerning the following question:

Hi,

I've got a perl script running through apache, which I want to call another program but run it in the background.

I've tried
system('/path/to/script');
system('/path/to/script &');
exec('as above');

These work, but the webpage just hangs waiting for the process to finish, or in this case, until Apache times out after 90 seconds (on my machine). How do I just fire off a background process? The background process is not a perl script by the way.

Thanks

Comment on Creating a background task from the web

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Re: Creating a background task from the web by Corion (Patriarch) on Jan 28, 2009 at 14:20 UTC
merlyn wrote Watching long processes through CGI, which details all you want.	[reply]
Re: Creating a background task from the web by citromatik (Curate) on Jan 28, 2009 at 14:41 UTC
...but the webpage just hangs waiting for the process to finish You need to fork and exec for an asynchronous response of the server: Here is some documentation that can help you: Re: spawning Perl scripts by Abigail Web Techniques Column 20 by merlyn hope this helps citromatik	[reply]
Re: Creating a background task from the web by jethro (Monsignor) on Jan 28, 2009 at 14:56 UTC
Your second example should work, to demonstrate: `perl -e ' system("emacs &"); print "hello"; '` [download]	[reply] [d/l]
Re^2: Creating a background task from the web by jasonk (Parson) on Jan 29, 2009 at 17:00 UTC
This isn't a valid comparison, though. To compare it to a web application, you would have to run it as: `perl -e 'system( "emacs &"); print "hello";'; exit` [download] And at this point, depending on a variety of factors (whether it's a local shell or an ssh connection to another host, what shell you are using, what command you ran) the exit may work, or it may sit and wait for the background command to finish, since STDOUT and STDERR are still connected. www.jasonkohles.com We're not surrounded, we're in a target-rich environment!	[reply] [d/l]
Re^3: Creating a background task from the web by jethro (Monsignor) on Jan 29, 2009 at 18:38 UTC
You may have a point there. But shouldn't STDOUT and STDERR be inherited from the webserver and therefore the webserver not have to wait for a close.	[reply]