use strict;
use warnings;
use File::Copy;

# yes, it is Windows XP and a drive letters assigned to a USB and a NAS drive.
# Indir and outdir will be a parameter in this format.

my $inDir = "M:\\AllFiles";
my $outDir = "n:\\allFiles";


# test 1 straight in out in DOS format.
MoveFiles($inDir,$outDir);

# test 2 Try within quotes.
MoveFiles("$inDir","$outDir");

# test 3 Try selecting ALL files in the directory
MoveFiles($inDir."\\*", $outDir);

sub MoveFiles {
    my ( $source, $destination ) = @_;
    my $source_size = (-s $source) || 0;
    my $destination_size = (-s $destination) || 0;
move( $source, $destination ) if ($destination_size > $source_size);
}