frappy-scan: resolve ip numbers to names

Change-Id: I07bf7c274aeb52f2aaa58e8aa2f3bcb2788556ee

bin/frappy-scan

@@ -59,16 +59,23 @@ def decode(msg, addr):
 
 
 def print_answer(answer, *, short=False):
+    try:
+        hostname = socket.gethostbyaddr(answer.address)[0]
+        address = hostname
+        numeric = f' ({answer.address})'
+    except Exception:
+        address = answer.address       
+        numeric = ''
     if short:
         # NOTE: keep this easily parseable!
-        print(f'{answer.equipment_id} {answer.address}:{answer.port}')
+        print(f'{answer.equipment_id} {address}:{answer.port}')
         return
-    print(f'Found {answer.equipment_id} at {answer.address}:')
+    print(f'Found {answer.equipment_id} at {address}{numeric}:')
     print(f'  Port: {answer.port}')
     print(f'  Firmware: {answer.firmware}')
     desc = answer.description.replace('\n', '\n    ')
     print(f'  Node description: {desc}')
-    print()
+    print('-' * 80)
 
 
 def scan(max_wait=1.0):
@@ -119,10 +126,14 @@ def listen(*, short=False):
 if __name__ == '__main__':
     parser = argparse.ArgumentParser()
     parser.add_argument('-l', '--listen', action='store_true',
-                        help='Print short info. '
-                        'Keep listening after the broadcast.')
+                        help='Keep listening after the broadcast.')
+    parser.add_argument('-s', '--short', action='store_true',
+                        help='Print short info (always on when listen).')
     args = parser.parse_args(sys.argv[1:])
+    short = args.listen or args.short
+    if not short:
+        print('-' * 80)
     for answer in scan():
-        print_answer(answer, short=args.listen)
+        print_answer(answer, short=short)
     if args.listen:
-        listen(short=args.listen)
+        listen(short=short)