Find ports that are not in the requeirement of others

[Olivier]

Hi,

After a couple of years runnig and using one single machine, installing
some ports for testing, etc. I end up with hundred of ports and
packages, especially libraries that I never use directly, so am not
really aware of.

Is there an incantation of pkg(8) that can list all the ports that are a
leaf in the tree of the installed ports.

For example, emacs would be such a leaf, or wireshark. But libjpeg is
not a leaf (unless I delete emacs and all other software that use it).

I know I could make something like that but why reinventing the wheel?

Best regards,

Olivier
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