public static  void main(String[] args) 
{
        try {
            rootLoader(args);
        } catch (Throwable t) {
            t.printStackTrace();
        }
}

 static  void printUsage() 
{
        System.out.println("possible programs are 'groovyc','groovy','console', and 'groovysh'");
        System.exit(1);
}

 public static  void rootLoader(String[] args) 
{
        String conf = System.getProperty("groovy.starter.conf",null);
        LoaderConfiguration lc = new LoaderConfiguration();
        // evaluate parameters
        boolean hadMain=false, hadConf=false, hadCP=false;
        int argsOffset = 0;
        while (args.length-argsOffset >0 && !(hadMain && hadConf && hadCP)) {
            if (args[argsOffset].equals("--classpath")) {
                if (hadCP) break;
                if (args.length==argsOffset+1) {
                    exit("classpath parameter needs argument");
                }
                lc.addClassPath(args[argsOffset+1]);
                argsOffset+=2;
                hadCP=true;
            } else if (args[argsOffset].equals("--main")) {
                if (hadMain) break;
                if (args.length==argsOffset+1) {
                    exit("main parameter needs argument");
                }
                lc.setMainClass(args[argsOffset+1]);
                argsOffset+=2;
                hadMain=true;
            } else if (args[argsOffset].equals("--conf")) {
                if (hadConf) break;
                if (args.length==argsOffset+1) {
                    exit("conf parameter needs argument");
                }
                conf=args[argsOffset+1];
                argsOffset+=2;
                hadConf=true;
            } else {
                break;
            }            
        }
        // this allows to override the commandline conf
        String confOverride = System.getProperty("groovy.starter.conf.override",null);
        if (confOverride!=null) conf = confOverride;
        // we need to know the class we want to start
        if (lc.getMainClass()==null && conf==null) {
            exit("no configuration file or main class specified");
        }
        // copy arguments for main class 
        String[] newArgs = new String[args.length-argsOffset];
        for (int i=0; i< newArgs.length; i++) {
            newArgs[i] = args[i+argsOffset];
        }        
        // load configuration file
        if (conf!=null) {
            try {
                lc.configure(new FileInputStream(conf));
            } catch (Exception e) {
                System.err.println("exception while configuring main class loader:");
                exit(e);
            }
        }
        // create loader and execute main class
        ClassLoader loader = new RootLoader(lc);
        Method m=null;
        try {
            Class c = loader.loadClass(lc.getMainClass());
            m = c.getMethod("main", new Class[]{String[].class});
        } catch (ClassNotFoundException e1) {
            exit(e1);
        } catch (SecurityException e2) {
            exit(e2);
        } catch (NoSuchMethodException e2) {
            exit(e2);
        }
        try {
            m.invoke(null, new Object[]{newArgs});
        } catch (IllegalArgumentException e3) {
            exit(e3);
        } catch (IllegalAccessException e3) {
            exit(e3);
        } catch (InvocationTargetException e3) {
            exit(e3);
        }
}