def hash(argc):
    """hash: various hashing functions.
    
    Usage:
        hash (md5|sha256) FILE
        hash (md5|sha256) --string STRING
    """
    
    if argc.args['FILE']:
        if argc.args['md5']:
            return md5(open(argc.args['FILE']).read())

        elif argc.args['sha256']:
            return sha256(open(argc.args['FILE']).read())

    elif argc.args['--string']:
        if argc.args['md5']:
            return md5(argc.args['STRING'])

        elif argc.args['sha256']:
            return sha256(argc.args['STRING'])