printing to a redirected stdout from a process that was called with "2>&1 > /dev/null &"
helgaorg at gmail.com
Tue Jan 30 00:12:37 CET 2007
Python File B changes sys.stdout to a file so all 'prints' are written
to the file. Python file A launches python file B with os.popen("./B
2>&^1 >dev/null &"). Python B's output disappears into never-never
I am working on a site that can kick off large-scale simulations. It
will write the output to an html file and a link will be emailed to
the user. Also, the site will continue to display "Loading..." if the
user wants to stick around.
The simulation is legacy, and it basically writes its output to stdout
(via simple print statements). In order to avoid changing all these
prints, I simply change sys.stdout before calling the output
functions. That works fine. The whole thing writes to an html file
On the cgi end, all I want my (python) cgi script to do is check for
form errors, make sure the server isn't crushed, run the simulation
and redirect to a loading page (in detail, I write a constantly
updating page to the location of the final output file. When the
simulation is done, the constantly updating file will be magically
replaced). The root problem is that the popen mechanism described
above is the only way I've found to truly 'Detach' my simulation
process. With anything else, Apache (in a *nix environment) sits and
spins until my simulation is done. Bah.
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