Arguments: [<command>]
    List available commands

def cmd_help(*args):
    """
    Arguments: [<command>]
    List available commands
    """
    if len(args) == 0:
        print("Possible commands are:")
        print("")
        for cmd_name in sorted(COMMANDS.keys()):
            cmd_func = COMMANDS[cmd_name]
            print("{}:".format(cmd_name))
            print("=" * (len(cmd_name) + 1))
            print("    {}".format(cmd_func.__doc__.strip()))
            print("")
    else:
        cmd_name = args[0]
        cmd_func = COMMANDS[cmd_name]
        print("{}:".format(cmd_name))
        print("=" * (len(cmd_name) + 1))
        print("    {}".format(cmd_func.__doc__.strip()))