Update Nix, optionalize some output

Author: pjkundert

nixpkgs.nix

@@ -1,4 +1,4 @@
 import (fetchTarball {
-  url = "https://github.com/NixOS/nixpkgs/archive/refs/tags/24.05.tar.gz";
-  sha256 = "1lr1h35prqkd1mkmzriwlpvxcb34kmhc9dnr48gkm8hh089hifmx";
+  url = "https://github.com/NixOS/nixpkgs/archive/refs/tags/25.05.tar.gz";
+  sha256 = "1915r28xc4znrh2vf4rrjnxldw2imysz819gzhk9qlrkqanmfsxd";
 })

server/enip/client.py

@@ -2236,8 +2236,9 @@ def main( argv=None ):
                 remains		= timeout - ( elapsed or 0 )
                 reply,_		= await_response( connection, timeout=remains )
                 if reply:
-                    print( "%s %2d from %r: %s" % (
-                        desc, counter, reply.peer, parser.enip_format( reply.get( path, reply ))))
+                    if printing:
+                        print( "%s %2d from %r: %s" % (
+                            desc, counter, reply.peer, parser.enip_format( reply.get( path, reply ))))
                     counter    += 1
                 if not reply or not args.broadcast:
                     # No reply or EOF w'in timeout, or reply but not --broadcast; done waiting