use PerlIO::encoding;
$PerlIO::encoding::fallback = Encode::FB_DEFAULT;

##</code><code>##

#!/usr/bin/perl
use PerlIO::encoding;
$PerlIO::encoding::fallback = Encode::FB_DEFAULT;

open my $fh, "<:encoding(UTF-8)", $ARGV[0] or die $!;

binmode STDOUT, ":encoding(UTF-8)";

while (<$fh>) { print }

##</code><code>##

foo
bär