Here, the file name is input by the user as a command-line argument ($ARGV[0]).

D:\>chcp 1252
Active code page: 1252

D:\>dir acentó.dat /b
acentó.dat

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

D:\>type test.pl
#!perl

use strict;
use warnings;

my $fn = shift;

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

D:\>
[download]

Fine, but if you have the user provide the filename at runtime, all goes to hell.


use strict;
use warnings;

my $fn;
print "\nType filename.\n";
chomp ($fn = <STDIN>);
print "\nOpening file named $fn\n";
if (open my $fh, '<', $fn) {
    print "Successfully opened file '$fn'\n";
    close $fh;
}
else {
    print "Error opening file '$fn': $!\n";
}
[download]

This works for me on WinXP with ActivePerl on a file named i.txt, but it fails if the file is called í.txt.
I'm sure it has to do with the encoding used by the console, but I'm not sure how to make it just work (TM) on any windows computer.
Here's a thread in which I asked about the problem - with no final answer, at least no simple and full solution: http://www.perlmonks.org/?node_id=859764