$ file -i /tmp/t.pl; perl /tmp/t.pl
/tmp/t.pl: text/plain; charset=utf-8
Can't use global $^▒▒▒▒▒▒▒ in "my" at /tmp/t.pl line 9, near "my $▒"
Unrecognized character \xA4 in column 6 at /tmp/t.pl line 9.

#! /usr/bin/env perl
use strict;
use warnings;
use 5.010;

say length("ä");

my $ä = "test";

say $ä;