Is there a generic canonical way for a package script to check network connectivity?

[Jonathan Kamens]

I need to be able to tell from one of my package scripts whether the 
host has networking connectivity.

I know I can call `nmcli networking connectivity` but that's only valid 
if NetworkManager is in use. How reasonable is it for me to assume that 
NetworkManager is in use? Is there a more generic, canonical way to do 
this check?

Thanks,

Jonathan Kamens