def show():
    if not is_configured():
        raise JutException('No configurations available, please run: `jut config add`')

    info('Available jut configurations:')
    index = 0
    for configuration in _CONFIG.sections():
        username = _CONFIG.get(configuration, 'username')
        app_url = _CONFIG.get(configuration, 'app_url')

        if app_url != defaults.APP_URL:
            if _CONFIG.has_option(configuration, 'default'):
                info(' %d: %s@%s (default)', index + 1, username, app_url)
            else:
                info(' %d: %s@%s', index + 1, username, app_url)

        else:
            if _CONFIG.has_option(configuration, 'default'):
                info(' %d: %s (default)' % (index + 1, username))
            else:
                info(' %d: %s' % (index + 1, username))

        index += 1
L{root.Resolver.lookupAddress} looks up the I{A} records for the
dataset/ETHPy150Open jut-io/jut-python-tools/jut/config.py/show--crossover with--dataset/ETHPy150Open twisted/twisted/twisted/names/test/test_rootresolve.py/RootResolverTests.test_lookupAddress