code: public final static void main(String[] args) {
          if (args.length < 3) {
              usage("Not enough arguments.");
          }   // end if: args.length < 3
          else {
              String flag = args[0];
              String infile = args[1];
              String outfile = args[2];
              if (flag.equals("-e")) {
                  Base64.encodeFileToFile(infile, outfile);
              }   // end if: encode
              else if (flag.equals("-d")) {
                  Base64.decodeFileToFile(infile, outfile);
              }   // end else if: decode    
              else {
                  usage("Unknown flag: " + flag);
              }   // end else    
          }   // end else
      }
docs: Encodes or decodes two files from the command line;
  <strong>feel free to delete this method (in fact you probably should)
  if you're embedding this code into a larger program.</strong>