fix usage and listing

src/sysalert/db.py

@@ -96,8 +96,8 @@ def get_services(db):
         GROUP BY
             service.name;
         ''')
-    db.commit()
     ret = {name: failures for (name, failures) in cur.fetchall()}
+    db.commit()
     return ret
 
 

src/sysalert/util.py

@@ -96,7 +96,11 @@ documentation for details.''')
                               help='''Force clear for all services if service is
                               not specified''')
 
-    return parser.parse_args()
+    args = parser.parse_args()
+    if not args.cmd:
+        parser.print_help()
+        sys.exit(1)
+    return args
 
 def cli():
     config = configparser.ConfigParser()
@@ -116,6 +120,7 @@ def cli():
             cli_list(args, db)
         elif args.cmd == 'clear':
             cli_clear(args, db)
+        else:
 
     sysalert.db.close(db)
     return ret