list active VNC connections from terminal

Question

I am looking for a way to list all the active VNC connection to a machine. I know I can get all the active connection of the machine by running netstat -na but I don't know how to filter just the connection for the VNC server. I am running OSX 10.8.3 , any hint?

Solution 1

VNC runs on port 5900 by default, so you should be able to do:

netstat -na | grep '[:.]5900'

(OS X uses . as a port delimiter, but on Linux it's : — the pattern above will match both)

Example on my OS X machine:

% netstat -na | grep '[:.]5900'
tcp4       0      0  *.5900                 *.*                    LISTEN     
tcp6       0      0  *.5900                 *.*                    LISTEN 

Solution 2

If you are running xrdp to connect to vnc, then 5900 will not show all the connections. Here is a slightly different answer:

netstat -na | grep '[:.]5900'

gives:

tcp        0      0 127.0.0.1:5918          0.0.0.0:*               LISTEN
tcp        0      0 127.0.0.1:5919          0.0.0.0:*               LISTEN
tcp        0      0 127.0.0.1:5913          0.0.0.0:*               LISTEN
tcp        0      0 127.0.0.1:5914          0.0.0.0:*               LISTEN
tcp        0      0 127.0.0.1:5915          0.0.0.0:*               LISTEN
tcp        0      0 127.0.0.1:5916          0.0.0.0:*               LISTEN
tcp        0      0 127.0.0.1:5917          0.0.0.0:*               LISTEN
tcp        0      0 127.0.0.1:5913          127.0.0.1:54546         ESTABLISHED
tcp        0      0 127.0.0.1:54546         127.0.0.1:5913          ESTABLISHED

Also see this answer for how to dig the port out of the process.