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user37342
Asked: 2020-12-20 04:31:18 +0800 CST

Can't read text file while it is being produced by running C-program

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I have a little c-program, d, that takes a long time and produces a lot of text output. When I run the the program with ./d I can see the output being scrolled on the screen but if I do
./d > d10.txt I can't read d10.txt with cat d10.txt until the program has finished. Why is this so and what can I do to monitor the output while the program is running? Thanks for any tip H

command-line

1 Answers

  1. You can't see the output because you are redirecting it into the file.

    To both see the output and store it in a file, use the tee program:

    ./d | tee d10.txt

    You could also do this, but it's much more work:

    > d10.txt
tail -f d10.txt &
./d >> d10.txt
kill %1
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