# Read the signing image_type from the client app via the socket
        $image_type = <$client_socket>;
        chop($image_type);
        
        # Setup some default filenames and command strings.
        my $unsigned_file = "unsigned.bin";
        my $signed_filename;
        my $output_file = "signed.$unsigned_file";
        my $rcv_filesize;
        my $hsm_cmd;
        my $buf;
        my $error = "ACK\n";

       $rcv_filesize = 0;                
       my $i = 1;
       while (-e $output_file) {
      $output_file = "output.$input_file$i";
    			$i++;
				}
      $abc_cmd = "abc.exe" -i $input_file -o $output_file"; 
      print $client_socket "ACK\n";


    system $abc_cmd;     # Run the command
        print "DONE\n";
        
        # Open the file for reading 
         open(INFILE, $output_file) || die "ERROR:  Could not open output_file for reading!\n";
        binmode INFILE;
        {
            local $/;
            $output_data = <INFILE>;
        }
        close(INFILE);

        print "$prefix Sending $output_file to the client... ";
        $client_socket->write($output_data, length($output_data));
        
        print length($output_data), " bytes: DONE\n";
        
        $client_socket->close();
        print "$prefix Socket closed, operation completed!\n";