def setup_datafiles(shell,params_info):
    """
    write the datafiles to disk
    build the parameters file
    """

    parameters_text_items = []
    for key,value in params_info.items():
        shell.write_file(value['path'], value['text'])
        parameters_text_items.append("%s:%s" % (value['type'],value['path']))

    # generate the parameters file to feed into the url
    parameters_text = '\n'.join(parameters_text_items)

    return parameters_text