getting the running patch level

[Roberto]

Hi all,
I would like to know if there is a command or a way to retrieve the "patch
level" (the handbook defines it "builds names" like 7.0-RELEASE-p1) of the
running system: just an example, if I run:

# freebsd-update fetch
...
No updates needed to update system to 9.0-RELEASE-p4


or:
...
The following files will be updated as part of updating to 9.0-RELEASE-p4:
...

but this give me no info about the current system; I tried a brief search in
config file but no luck;

again the question is:
is there a way to determine for a running server which "patch level" is
currently at ?

thanks
Roberto