You should be able to accomplish this using select and the special variable $| to turn off buffering: 
select(STDERR); 
$| = 1;
select(STDOUT); 
$| = 1;

[download]
Of course, you'll likely have trouble if you execute your command as listed above, since the channels will clobber each other. You probably mean 
script.pl > script.out 2>&1

[download]

#11929 First ask yourself `How would I do this without a computer?' Then have the computer do it the same way.

In reply to Re: interleaf stdout stderr to a file by kennethk
in thread interleaf stdout stderr to a file by hg2

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