use FileHandle;

sub pipe_from_fork ($) {
   my $parent = shift;
   pipe $parent, my $child or die;
   my $pid = fork();
   die "fork() failed: $!" unless defined $pid;
   if ($pid) {
       close $child;
   }
   else {
       close $parent;
       open(STDOUT, ">&=" . fileno($child)) or die;
   }
   $pid;
}

sub decompress_filehandle
{
  my $fh = shift;

  my $dfh = new FileHandle;

  # Must use pipe_from_fork because $dfh->open('-|') not yet implemented on
  # Windows. See perlfork for details
  unless (pipe_from_fork($dfh)) {
    # In child
    close $dfh;

    open(FRONT_OF_PIPE, '| c:\progra~1\cygwin\bin\gzip.exe -cd')
      or return (undef,"Can't execute \"$filter_command\" on file handle: $!");

    print FRONT_OF_PIPE <$fh>;

    $fh->close()
      or return (undef,"Can't execute \"$filter_command\" on file handle: $!");

    close FRONT_OF_PIPE;

    exit;
  }

  # In parent
  close $fh;
  return $dfh;
}

my $fh = new FileHandle('mailarc-1.txt.gz');
my $dfh = decompress_filehandle($fh);

print $_ while <$dfh>;