#!/usr/bin/perl

# This source file is encoded using UTF-8.
use utf8;

use strict;
use warnings;

# Use locale-dependent encoding for STDIO.
use open ':std', ':locale';

# Use locale-dependent encoding (by default)
# for all files opened in this scope.
# Unfortunately, <> ignores this directive.
use open IO => ':locale';

...

##</code><code>##

use open IO => ':encoding(UTF-8)';