#b1.pl
use strict;
use utf8;
$_="中文";

sub p{
    my $_=shift;
    binmode STDOUT, ":encoding(gbk)";
    print "$_\n";
}

p($_);
p($_);

__END__

##</code><code>##

#b2.pl
use strict;
use utf8;
$_="&#20013;&#25991;";
binmode STDOUT, ":encoding(gbk)";
print "$_\n";

##</code><code>##

binmode STDOUT, ":encoding(gbk)";
print "$_\n";

__END__

##</code><code>##

e:\home\pl>perl b1.pl
perl b1.pl
&#20013;&#25991;
"\x{0590}" does not map to cp936.
"\x{0384}" does not map to cp936.
\x{0590}\x{0384}

e:\home\pl>perl b2.pl
perl b2.pl
&#20013;&#25991;
&#20013;&#25991;