As long as you aim at using BeagleBone Black for server purposes, many ports are going to be used. You will soon need to know those that are already assigned. For example, ports 8080 and 8000 are very often required so they will be most probably defined in many default configuration files when you install an application. Then, to avoid port conflicts, you will want to retrieve those that are currently used. For this, enter the following command:

debian@arm:~$ sudo netstat -an | grep LISTEN | grep -v ^unix

tcp        0      0 0.0.0.0:1984            0.0.0.0:*               LISTEN
tcp        0      0 127.0.0.1:3306          0.0.0.0:*               LISTEN
tcp        0      0 127.0.0.1:11211         0.0.0.0:*               LISTEN
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN
tcp6       0      0 :::6600                 :::*                    LISTEN
tcp6       0      0 :::80                   :::*                    LISTEN
tcp6       0      0 :::22                   :::*                    LISTEN

In the beginning of this appendix, we have seen how to ease our life with aliases and functions.

I strongly suggest that you use the same technique with this long command. Thereafter, you won't hesitate any more to use it because you won't need to remember the whole syntax.