fix clearing and listing

src/sysalert/util.py

@@ -97,7 +97,7 @@ documentation for details.''')
                               not specified''')
 
     args = parser.parse_args()
-    if not args.cmd:
+    if 'cmd' not in args:
         parser.print_help()
         sys.exit(1)
     return args
@@ -126,13 +126,14 @@ def cli():
 
 def cli_list(args, db):
     for service, failures in sysalert.db.get_services(db).items():
-        if args.service and args.service == service:
+        if not args.service or (args.service and args.service == service):
             print(f'{service}: {failures} failures')
     return 0
 
 def cli_clear(args, db):
     if not args.service and not args.force:
-        print(f'No service specified, use "--force" to clear all services', sys.stderr)
+        print(f'No service specified, use "--force" to clear all services',
+              file=sys.stderr)
         return 1
     if args.service:
         sysalert.db.clear_failure(args.service, db)