hi Conley, ok thanks, but i think there must be some data structure (linked list etc.) where ROS stores its current running nodes? and each time any node(s) quit ROS updates that data structure. may be? regards -- View this message in context: http://ros-users.122217.n3.nabble.com/graph-of-nodes-tp1905890p1910908.html Sent from the ROS-Users mailing list archive at Nabble.com.