IConsoleFacet

public interface IConsoleFacet extends IRemote
{
    /** Fetch list of supported commands
     * @return  Array of commands.
     */
    public String[] getCommands();
    
    /** Fetch command description.
     * @throws CommandException  Thrown if command does not exist.
     */
    public String getCommandDescription(String cmd) throws CommandException;

    /** Execute a command.
     * @param command  The command being executed.
     * @param argument  Any command-specific arguments required to execute.
     * @throws CommandException  Thrown if command does not exist.
     */
    public Property[] execCommand(String command, Property[] argument)
        throws CommandException;
}

When a command is run with exec in the launcher its name and arguments are passed straight through to the execCommand() method. Its array of return values is what the launcher puts into $0, $1, $2, etc.