unifdefall(1) on FreeBSD
The text 269c2e9cc82e, as FreeBSD 7.2-RELEASE shipped it.
remove preprocessor conditionals from code
Flags it lists
-
-D -
-I -
-U -
-c -
-d -
-e -
-iD -
-iU -
-k -
-l -
-n -
-s -
-t