How about (at least on UNIX) 
open(STDERR,"|tee somefile 1>&2");

print STDERR "this goes to STDERR and somefile\n";

[download]
(The "1>2" ensures that what gets printed still goes to your main process's STDERR instead of STDOUT).

--JAS

In reply to Re: duplicating STDERR to a logfile... by jsegal
in thread duplicating STDERR to a logfile... by cadphile

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