Re: CGI and long running job
[EMAIL PROTECTED] wrote: Hello, I am using python and CGI to initiate a long running simulation (up to 5h long) on a remote machine. The main idea is that I use a form, enter the parameters and a CGI scripts start the simulation using these parameters. The structure of the script is: 1. Read paremeters 2. Display some information 3. Start the simulation For step 3 I use either os.system or os.popen(2). The problem is that the web server does not send the information of step 2 back to the browser, unless step 3 is completed. The browser simply waits for a response, without displaying anything. How can I just read the params, display the info I want, start the simulation and then terminate either the script or at least the connection to the browser without having to wait for the simulation to finish? I am using activestate python 2.4, Apache and WinXP. Thanks a lot for your help. Maybe you could use 'os.spawn' variants with the P_NOWAIT parameter... (not sure of the syntax here, it's in the doc) Good luck! -- http://mail.python.org/mailman/listinfo/python-list
Re: CGI and long running job
[EMAIL PROTECTED] wrote: [EMAIL PROTECTED] wrote: Hello, I am using python and CGI to initiate a long running simulation (up to 5h long) on a remote machine. The main idea is that I use a form, enter the parameters and a CGI scripts start the simulation using these parameters. The structure of the script is: 1. Read paremeters 2. Display some information 3. Start the simulation For step 3 I use either os.system or os.popen(2). The problem is that the web server does not send the information of step 2 back to the browser, unless step 3 is completed. The browser simply waits for a response, without displaying anything. How can I just read the params, display the info I want, start the simulation and then terminate either the script or at least the connection to the browser without having to wait for the simulation to finish? I am using activestate python 2.4, Apache and WinXP. Thanks a lot for your help. Maybe you could use 'os.spawn' variants with the P_NOWAIT parameter... (not sure of the syntax here, it's in the doc) Good luck! Thanks for answering. I tried that but it didn't work. Nothing is sent back to the browser until the spawned process has ended. This is true even if the spawn command (or any other similar command) is the last statement of the script. Is there some way to send back to the browser whatever info I need, close the connection and then continue executing the commands I need, using the same script? -- http://mail.python.org/mailman/listinfo/python-list
Re: CGI and long running job
Le die Fri, 02 Dec 2005 20:35:52 -0800, merry.sailor ha scribite: For step 3 I use either os.system or os.popen(2). The problem is that the web server does not send the information of step 2 back to the browser, unless step 3 is completed. The browser simply waits for a response, without displaying anything. How can I just read the params, display the info I want, start the simulation and then terminate either the script or at least the connection to the browser without having to wait for the simulation to finish? Sounds weird. What if you connect to the webserver via telnet? Do you get any output? you could try to call sys.stdout.flush() in the CGI, but I never had the need to do that. Maybe it's just a browser's problem? -- Saluti, Mardy http://interlingua.altervista.org -- http://mail.python.org/mailman/listinfo/python-list
Re: CGI and long running job
Hello Mardy, thanks a lot for your help. I found the problem. Your suggestion made me look into some things I haven't thought before :-). I don't know if it is a browser/server/mine fault. The problem was that I was sending text/plain and a txt file. I soon as I started sending back to the browser text/html and an html file, I started getting the things I wanted on screen, but the browser still waited for the script to terminate, which resulted in a timeout. After I also closed stdout, everything worked fine. The strange thing is that I tried closing stdout with the plain text before, but it didn't work. -- http://mail.python.org/mailman/listinfo/python-list
Re: CGI and long running job
[EMAIL PROTECTED] wrote:
Hello,
I am using python and CGI to initiate a long running simulation (up to
5h long) on a remote machine. The main idea is that I use a form, enter
the parameters and a CGI scripts start the simulation using these
parameters. The structure of the script is:
1. Read paremeters
2. Display some information
3. Start the simulation
For step 3 I use either os.system or os.popen(2). The problem is that
the web server does not send the information of step 2 back to the
browser, unless step 3 is completed. The browser simply waits for a
response, without displaying anything. How can I just read the params,
display the info I want, start the simulation and then terminate either
the script or at least the connection to the browser without having to
wait for the simulation to finish?
You need to close stdout, which closes the socket and allows the browser to
finish. This is what I use:
# We flush stdout, fork, then close stdout. This closes the HTTP socket,
# allowing the browser to continue while we munge with sendmail.
sys.stdout.flush()
if os.fork(): return
fw = open('/dev/null','w')
os.dup2(fw.fileno(),1)
os.dup2(fw.fileno(),2)
--
- Tim Roberts, [EMAIL PROTECTED]
Providenza Boekelheide, Inc.
--
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