Hey - thanks for this!

My opinion right now is that this might be a little too much. I'd like for our interaction with the user to be as clear and concise as possible. I think the "sudo" suggestion is just there to give most users a way they're familiar with to solve the current problem quickly. But I'm open to be convinced otherwise if you disagree.

The thing is, when using sudo, the entire program has root permissions and is executed in the root environment (unless you use sudo -E though) while just a few permissions would be granted with the setcap wrapper. Also it might possible then to allow non-sudoers to use bandwhich by creating a bandwhich group and let it own the bandwhich binary.

I agree though that the message might seem a bit bloated. While the macOS-message is fine, I'd suggest something like this for Linux:

nsufficient permissions to listen on network interface(s). Please try one of the following fixes:

* run bandwhich with sudo
* create a `setcap(8)` wrapper for `bandwhich` with the permissions `cap_net_raw,cap_net_admin+ep`

Sounds good, let's do it.

Looks great, thanks!