#!/usr/bin/perl --

use strict;
use warnings;
use utf8;
use HTML::Entities;

binmode STDOUT, ':encoding(UTF-8)';
{
    my $line = "This is a test of \xe2\x80\x9cquotes\xe2\x80\x9d\n";
    print encode_entities($line, "\200-\377"); # looking for “ ” in the output
    print $line;
}
print '#' x 11, "\n";
{
    my $line = 'xThis is a test of '.chr(8220).'quotes'.chr(8222)."\n";
    print encode_entities($line, '\x{201c}\x{201e}');
    print $line;
}
print '#' x 11, "\n";
{
    my $line = 'xThis is a test of '.chr(8220).'quotes'.chr(8222)."\n";
    print encode_entities($line, chr(8220).chr(8222));
    print $line;
}

__END__
This is a test of “quotes”
This is a test of “quotes”
###########
xThis is a test of “quotes„
xThis is a test of “quotes„
###########
xThis is a test of “quotes„
xThis is a test of “quotes„