parser.add_argument('crontab',help='the crontab file to parse')
parser.add_argument('--whitelist','-w',action='append',dest='whitelisted_users',help='A user to ignore when warning of unrecognized users This argument may be passed multiple times.',default=['postgres','buildbot'])
parser.add_argument('-n','--no-check-passwd',action='store_false',dest='check_passwd',help='Disable user lookup')