use strict;
use warnings;

my $x = "\x{42f}"."\n";

warn "printing to /tmp/foo\n";

open(my $fh, ">:utf8", "/tmp/foo") or die "open: $!";
print {$fh} $x;

warn "printing to STDOUT\n";

print $x;

warn "printing to duped STDOUT\n";

open(my $gh, ">&:utf8", \*STDOUT) or die "open: $!";
print {$gh} $x;

##</code><code>##

$ LANG=C ./script
printing to /tmp/foo
printing to STDOUT
Wide character in print at t5 line 13.
&#1162;
printing to duped STDOUT
&#1162;

$ LANG=en_US.UTF-8 ./script
printing to /tmp/foo
printing to STDOUT
&#1162;
printing to duped STDOUT
&#1162;

$ LANG=C ./script > /tmp/out
printing to /tmp/foo
printing to STDOUT
Wide character in print at t5 line 13.
printing to duped STDOUT
Wide character in print at t5 line 18.

$ LANG=en_US.UTF-8 ./script > /tmp/out
printing to /tmp/foo
printing to STDOUT
printing to duped STDOUT
Wide character in print at t5 line 18.