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Tip #23  

It can be useful to not only know what has gone to stdout and stderr but also where they occurred with respect to each other.
Allow stderr to go to err.txt, stdout to out.txt and both to mix.txt

((./program 2>&1 1>&3 | tee ~/err.txt) 3>&1 1>&2 | tee ~/out.txt) > ~/mix.txt 2>&1