use strict;
use warnings;
my $INV_CHAR;

print "Testing for valid win32 filenames...\nThe following characters are invalid.\n";
print '\\/:*?"<>|',"\n\n";

while (<DATA>) {
  chomp;
  print "filename: [",$_,"] is";
  print validate_it($_) ? " valid.\n" :
                             " not valid!\n\t Filename contains \"$INV_CHAR\"\n" .
			                "\ttry: [" . sanitize_it($_,'_') . "]\n";
}

sub validate_it {
  local $_;
  $_ = shift;

  return /\\|\/|:|\*|\?|"|<|>|\|/ ? do { $INV_CHAR = $&; undef; } :
                  1;
}

sub sanitize_it {
  $_[0] =~ s/\\|\/|:|\*|\?|"|<|>|\|/$_[1]/g;
  return $_[0];
}


__DATA__
file1
file2$is
this)ok
this-ok_too..
this-good.mp4
bad:
b:a:d?--\
not<good>
*is*bad/
?what?is:good
this|ok|not