my $FILE = sub 
{
    my $file = shift;

    if($file =~ m!\A
        ([A-Za-z]:\\)? # Optional DOS drive (such as 'C:\')
        (
            [/\\]*? # Allow either '/' or '\' as a directory seperator 
    	    [-\.\w\s]+? # Allow certain characters as the filename 
        )+ 
        \z!x) { 
        return ($1 . $2, "Passed");
    }
    else {
        return (undef, "$file is not a valid filepath");
    }
};