You are right, Win32::Unicode allows the problem to be fixed, though the code no longer runs under Linux/OS-X.

Grep says my codebase has 67 instances of -[fdew] file test operators that would need translating to "file_type" equivalents (not a 1:1 match unfortunately), and 28 of "open|close" that would need changing, not to mention instances where I pass the name of an image file to functions to create/resize displayable images. These may accept file handles instead, but viewed any which way, it's LOT of work I'd rather avoid ;-)

I must also admit I can't immediately see any way of doing this in a platform independent way that maintains a single codebase.

The code is my Tk based test case for the problem. The commented out lines in "sub test_file" run fine with Linux/OS-X but fail under win32. Each commented out line is followed by a Win32::Unicode equivalent that "fixes" the problem for win32:

#!/bin/perl
#
# Tk demo replicates command line demo to read and checks files with e
+xtended chars in the path
#

use strict;
use warnings;
use utf8;
use Tk;
use Cwd;
use File::List;
use File::Spec;
use File::Basename;

# These modules replicate those used by the TagSuite environment
# but are not actuall used here.
use Carp (qw/ croak /);
use Encode;
use POSIX;
use XML::LibXML;
use File::Spec;
use Debug::Simple;
use Tk qw/ Ev /;
use Tk::PNG;
use Tk::JPEG;
use Tk::widgets qw/ NoteBook BrowseEntry Dialog DialogBox FBox Pane/;
use Tk::ProgressBar;
use Tk::Splashscreen;
use GD::Image;
use Image::Resize;
use Image::ExifTool qw/ :Public /;
use MIME::Base64;
use DBM::Deep;
use LWP::Simple;
use HTML::TokeParser;
use File::Copy;
use File::Path;
use Math::BigInt;


my $path;
my $win;
my $t1;

MAIN:
{
  init_gui();
  $path = File::Spec->catfile(getcwd(), 'data');
  load();
  MainLoop;
}

sub init_gui
{
  Tk::CmdLine::SetArguments(qw(-geometry +410+300));
  $win = MainWindow->new(-title=>'Tk wrapper', );
  $win->protocol('WM_DELETE_WINDOW', sub { exit; });
  $win->resizable(0, 0);
  my $f1 = $win->Frame();
  my $f2 = $win->Frame();

  $t1 = $f1->Scrolled('Text', -scrollbars=>'oe', -wrap=>'word', -heigh
+t=>'26', -width=>100, );
  $t1->pack(-anchor=>'e', -fill=>'both');
  my $b1 = $f2->Button(-text=>'Browse...', -width=>10, -command=>\&sel
+ect);
  $b1->pack(-anchor=>'e', -fill=>'both');

  $f1->grid(-row=>0, -column=>0, -padx=>8, -pady=>4, -sticky=>'n', );
  $f2->grid(-row=>1, -column=>0, -padx=>8, -pady=>4, -sticky=>'n', );

  return;
}

sub load
{
  my $lister = File::List->new($path);
  my @files = @{ $lister->find('') };
  foreach my $file (@files) {
    test_file($file);
  }
  return;
}

sub test_file
{
  my $file = shift;
  my $txt = '';

  use Win32::Unicode::File;
  my $dh = Win32::Unicode::File->new;

  my $dir = dirname($file);
  #if (! -d $dir) {
  if (! file_type d => $dir) {
    $t1->insert('end', "ERROR: Base Dir '$dir' does not exist!\n");
    return;
  }
  #$txt = (-w $dir) ? "Dir '$dir' is Writable by you\n" : "ERROR: dir 
+'$dir' NOT writable by you\n";
  $txt = (! file_type r=>$dir) ? "Dir '$dir' is Writable by you\n" : "
+ERROR: dir '$dir' NOT writable by you\n";
  $t1->insert('end', $txt);

  #if (! -f $file) {
  if (file_type e=>$file) {
    $t1->insert('end', "ERROR: File '$file' does not exist!\n");
    return;
  }

  #if (open my $in, '<', $file) {
  if ($dh->open('<', $file)) {
    #close $in;
    $dh->close;
    $txt = "File '$file' opened Ok\n";
  }
  else {
    $txt = "ERROR: Unable to open '$file'\n";
  }
  $t1->insert('end', $txt);

  return;
}

sub select
{
  my $filename = $win->getOpenFile(
     -defaultextension => '',
     -initialdir       => $path,
     -title            => 'Select file',
  );
  if ($filename) {
    test_file($filename);
  }
  return;
}
[download]

The data tree looks like this (note the accented 'ô' of Zatochi):

data
  |
  +- Pan's Labyrinth (2006)
  |    |
  |    +- mymovies.xml
  |    |
  |    +- BDMV
  |        |
  |        +- index.TAG
  |
  +- Zatôichi 01 - The Tale of Zatoichi (1962)
       |
       +- mymovies.xml
       |
       +- VIDEO_TS
           |
           +- VIDEO_TS.TAG
[download]