use strict;
use warnings;
use Getopt::Long qw(GetOptions);
sub usage {
   if (@_) {
      my ($msg) = @_;
      chomp($msg);
      print(STDERR "$msg\n");
   }

GetOptions(
       'root=s' => \my $dir,
    'out=s' => \my $out,
    'file=s' => \my $file,
)
    or usage();