Python CGI - Accepting Input, Invoking Another Process, Ending CGI

[LarsenMTL]

Python Users:

Based on previous suggestions from this group, I'm attempting to write
a python CGI that takes input from an HTML form, invokes a second
python script using this input, tells the user that their process has
started, ends the cgi output and later emails the results of the
invoked script.

My problem is that no mater how I invoke the 2nd script (spawnlp with
P_NOWAIT, system with &, etc..) the CGI caller continues to run until
it finishes. If you press the stop button or close the browser
certain portions of the 2nd script finish but not all of it. In
paticular the 2nd script uses teTex (invoked by os.system) to process
some tex files, this always errors out if the browser is closed or
stopped.

Regardless of all that, what is the proper way to have a python CGI
batch another python script?

Thanks,

Mark

 

[Diez B. Roggisch]

Based on previous suggestions from this group, I'm attempting to write

a python CGI that takes input from an HTML form, invokes a second
python script using this input, tells the user that their process has
started, ends the cgi output and later emails the results of the
invoked script.

My problem is that no mater how I invoke the 2nd script (spawnlp with
P_NOWAIT, system with &, etc..) the CGI caller continues to run until
it finishes. If you press the stop button or close the browser
certain portions of the 2nd script finish but not all of it. In
paticular the 2nd script uses teTex (invoked by os.system) to process
some tex files, this always errors out if the browser is closed or
stopped.

Did you try to daemonize your script? That will decouple it from the running
process, so maybe that helps. In the aspn cookbook there is a good recipe
for daemonizing.

 

[Eric Walstad]

Python Users:

Based on previous suggestions from this group, I'm attempting to write
a python CGI that takes input from an HTML form, invokes a second
python script using this input, tells the user that their process has
started, ends the cgi output and later emails the results of the
invoked script.

My problem is that no mater how I invoke the 2nd script (spawnlp with
P_NOWAIT, system with &, etc..) the CGI caller continues to run until
it finishes. If you press the stop button or close the browser
certain portions of the 2nd script finish but not all of it. In
paticular the 2nd script uses teTex (invoked by os.system) to process
some tex files, this always errors out if the browser is closed or
stopped.

Regardless of all that, what is the proper way to have a python CGI
batch another python script?

Thanks,

Mark

Hi Mark,

I had to do something like this in mod_python. I ended up using a
mod_python function to detach the process from the request. I don't know
how mod_python handles it, but it worked for me may be a lead for you to
follow (looking at the mod_python source, that is):
<http://www.modpython.org/pipermail/mod_python/2004-June/015719.html>

Best,

Eric.

 

[LarsenMTL]

Did you try to daemonize your script? That will decouple it from the running
process, so maybe that helps. In the aspn cookbook there is a good recipe
for daemonizing.

Thanks. I think I got it. Looking at that recipe hinted me at the
idea that I need to close or redirect stdin, stdout and stderr. Some
searches around here confirmed that.

Cheers.

 

[Eric Walstad]

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Thanks. I think I got it. Looking at that recipe hinted me at the
idea that I need to close or redirect stdin, stdout and stderr. Some
searches around here confirmed that.

Cheers.

Hi Mark,

Would you mind posting a snippet of how you solved the problem? I'd
appreciate seeing what you did.

Thanks,

Eric.
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