This is very weird. Using 5.8.0 (useperlio=defined) and 5.005 (useperlio=undef) on FreeBSD, the first snippet doesn't do anything. The second, however, works. Some playing around with filehandle duplication and copying (using the <&=FILEHANDLE construction) got me something that does work: 
close(STDIN);
open(STDIN, "<&=DATA");
while(<STDIN>){
  print "STDIN: $_";
}
__DATA__
Foo
Bar
Quux

[download]
Of course this doesn't help explaining the problem, but it adds a rather strange case to it. Time for some pondering.

Arjen

In reply to Re: Dup oddity OR Is it cargo cult if you wrote it yourself? by Aragorn
in thread Dup oddity OR Is it cargo cult if you wrote it yourself? by belg4mit

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