#!/usr/bin/perl
    use strict;
    use warnings;

    my $utf8="\xe9";

    open STDOUT, ">>:utf8", 'test.txt'  or die $!;
    print "No close: ",$utf8,"\n";

    close STDOUT;
    open STDOUT, ">>:utf8", 'test.txt'  or die $!;
    print "Close: ",$utf8,"\n";


PRINTS:
    No close: \xe9    (not literally - prints character \xe9, not UTF-8 encoded)
    Close: é