def METHOD_NAME(loader, node):
    directive = interpolate(node.value, variables)
    tf = tempfile.NamedTemporaryFile()
    tf.close()
    if os.system("%s > %s" % (directive, tf.name)) != 0:
        raise OnlYamlError("Script execution '%s' failed." % directive)
    return loadf(tf.name, variables)