Only in perl 5.6, in which it's a new feature. 5.5 didn't do that. (Unless you pre-populated the variable with a IO::Handle-ish object.) And it has to be a variable that only has undef in it. Otherwise, it's treated as a symbolic reference, which may not succeed if you have "use strict refs" turned on.

-- Randal L. Schwartz, Perl hacker