getoptdemo.java

用java实现的通用解释器

import gnu.getopt.LongOpt;
import gnu.getopt.Getopt;

/*
 * This sample code was written by Aaron M. Renn and is a demonstration
 * of how to utilize some of the features of the GNU getopt package.  This
 * sample code is hereby placed into the public domain by the author and
 * may be used without restriction.
 */

public class GetoptDemo
{

public static void
main(String[] argv)
{
 int c;
 String arg;
 LongOpt[] longopts = new LongOpt[3];
 // 
 StringBuffer sb = new StringBuffer();
 longopts[0] = new LongOpt("help", LongOpt.NO_ARGUMENT, null, 'h');
 longopts[1] = new LongOpt("outputdir", LongOpt.REQUIRED_ARGUMENT, sb, 'o'); 
 longopts[2] = new LongOpt("maximum", LongOpt.OPTIONAL_ARGUMENT, null, 2);
 // 
 Getopt g = new Getopt("testprog", argv, "-:bc::d:hW;", longopts);
 g.setOpterr(false); // We'll do our own error handling
 //
 while ((c = g.getopt()) != -1)
   switch (c)
     {
        case 0:
          arg = g.getOptarg();
          System.out.println("Got long option with value '" +
                             (char)(new Integer(sb.toString())).intValue()
                             + "' with argument " +
                             ((arg != null) ? arg : "null"));
          break;
          //
        case 1:
          System.out.println("I see you have return in order set and that " +
                             "a non-option argv element was just found " +
                             "with the value '" + g.getOptarg() + "'");
          break;
          //
        case 2:
          arg = g.getOptarg();
          System.out.println("I know this, but pretend I didn't");
          System.out.println("We picked option " +
                             longopts[g.getLongind()].getName() +
                           " with value " + 
                           ((arg != null) ? arg : "null"));
          break;
          //
        case 'b':
          System.out.println("You picked plain old option " + (char)c);
          break;
          //
        case 'c':
        case 'd':
          arg = g.getOptarg();
          System.out.println("You picked option '" + (char)c + 
                             "' with argument " +
                             ((arg != null) ? arg : "null"));
          break;
          //
        case 'h':
          System.out.println("I see you asked for help");
          break;
          //
        case 'W':
          System.out.println("Hmmm. You tried a -W with an incorrect long " +
                             "option name");
          break;
          //
        case ':':
          System.out.println("Doh! You need an argument for option " +
                             (char)g.getOptopt());
          break;
          //
        case '?':
          System.out.println("The option '" + (char)g.getOptopt() + 
                           "' is not valid");
          break;
          //
        default:
          System.out.println("getopt() returned " + c);
          break;
     }
 //
 for (int i = g.getOptind(); i < argv.length ; i++)
   System.out.println("Non option argv element: " + argv[i] + "\n");
}

} // Class GetoptDemo