D:\>chcp 850
Active code page: 850

D:\>perl test.pl acentó.dat
Successfully opened file 'acent¾.dat'

D:\>chcp 65001
Active code page: 65001

D:\>perl test.pl acentó.dat
Successfully opened file 'acent.dat'


D:\>type test.pl
#!perl

use strict;
use warnings;

my $fn = shift @ARGV;

if (open my $fh, '<', $fn) {
    print "Successfully opened file '$fn'\n";
    close $fh;
}
else {
    print "Error opening file '$fn': $!\n";
}

D:\>