#!/usr/bin/perl -wT
use strict;
use CGI;

# variables
my ($in, $from_file, $from_url);

# HTTP header
print qq|Content-type: text/html; charset=utf-8nn|;

# from utf-8 file
open($in, '<', './utf-8.txt');
$in or die $!;
($from_file) = <$in>;
print "<h1>from utf-8 file</h1>n";
print "<p>character: ", $from_file, "</p>n";
print '<p>length: ', length($from_file), "</p>n";

# from url encoded
print "<h1>from url encoded</h1>n";
$from_url = '%F1';
$from_url = CGI::unescape($from_url);
print "<p>character: ", $from_url, "</p>n";
print '<p>length: ', length($from_url), "</p>n";

utf-8.txt: UTF-8 Unicode text, with no line terminators

Distributor ID: Ubuntu
Description:    Ubuntu 16.04.2 LTS
Release:        16.04
Codename:       xenial