Is there a flag I can pass to either `df` or `mount` to make them display results for only locally-mounted filesystems?
Solution 1:
df -l. This depends on network filesystems being properly identified as such, though.
Solution 2:
Okay, as seems to be the case 75% of the time, I've actually tripped over the answer to my own question. The -t and -x flags for df will do what I'm looking for.
-t [type] will list filesystems matching fs TYPE [type]
-x [type] will list filesystems NOT matching fs TYPE [type]
I.e., for me to exclude NFS-mounted filesystems, the command is df -x nfs.