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My issue is that I have a function call it function1 which runs indefinitely. The function itself echo's "hello" every 1 second. Using the command:

function1 >> temp.txt

Every 1 second if I am to view the file temp.txt I should see a new line with "hello". However what's happening is that the function doesn't write to the file until its finished running. Therefore if I am to kill the function nothing will be written. Does anyone know of something I can do in this situation that will basically dynamically update temp.txt?

I have a python script set up the following way:

while [1>0]: print "hello" time.sleep(1)

Therefore this will always be running. Now I call this in a bash script

python pythonscript.py >> temp.txt

If I kill the process no data is logged.

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I wonder that it works that way -- but the easiest thing to come up with would be turning your function into a separate shell script to be called instead. Would that be an acceptable solution? –  Izzy Jul 20 '12 at 19:55
It would be extremely difficult to do this. Looking for a simpler solution –  Matt Stokes Jul 20 '12 at 20:15
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1 Answer 1

up vote 2 down vote accepted

Now that you mention it is not a shell function, but a python function in a python script: That explains some, and here comes your answer:

printing - How to flush output of Python print? - Stack Overflow

You need to put that inside your python function's loop: sys.stdout.flush() -- and of course you need to import sys before (or from sys import ... if you only need a part of it).

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Works perfectly thank you! –  Matt Stokes Jul 23 '12 at 14:31
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