asn: mutualize runtime parameters

1 files changed, 19 insertions, 9 deletions

diff --git a/asn.py b/asn.py
index 0eb8c6c..e59563e 100755
--- a/asn.py
+++ b/asn.py
@@ -268,17 +268,27 @@ if __name__ == '__main__':
     args = parser.parse_args()
 
     db = DB()
-    if args.host and args.port:
-        listen = Listener(db, args.host, args.port)
-    elif args.update:
+    if not len(sys.argv) > 1:
+        parser.print_help(sys.stderr)
+        sys.exit()
+
+    if args.populate and args.update:
+        log.error('--populate and --update used; redundant, use one')
+        sys.exit()
+
+    if args.populate:
+        log.info('creating and populating db cache...')
+        db.populate_db()
+
+    if args.update:
         log.info('checking remote repository for new dataset...')
         if db.update():
-            log.info('dataset updated, creating/populating cache...')
+            log.info('dataset fetched and updated')
             db.populate_db()
         else:
             log.info('no changes since last update')
-    elif args.populate:
-        log.info('creating/populating cache...')
-        db.populate_db()
-    else:
-        parser.print_help(sys.stderr)
+
+    if args.host and args.port:
+        log.info(f'listening on {args.host}:{args.port}')
+        listen = Listener(db, args.host, args.port)
+