def get_alias(infos):
    """Get aliases of all parameters.

    Parameters
    ----------
    infos : list
        Content of the config header file.

    Returns
    -------
    pairs : list
        List of tuples (param alias, param name).
    """
    pairs = []
    for x in infos:
        for y in x:
            if "alias" in y:
                name = y["name"][0]
                alias = y["alias"][0].split(',')
                for name2 in alias:
                    pairs.append((name2.strip(), name))
    return pairs