def parse_atfile_cat(input):
    """
    Return the list of catalog filenames specified as part of the input @-file

    """
    with open(input[1:]) as f:
        catlist = []
        catdict = {}
        for line in f.readlines():
            if line[0] == '#' or not line.strip():
                continue
            lspl = line.split()
            if len(lspl) > 1:
                catdict[lspl[0]] = lspl[1:]
                catlist.append(lspl[1:])
            else:
                catdict[lspl[0]] = None
                catlist.append(None)
    return catlist, catdict
