+// While rand(3) specifies RAND_MAX, random(3) says that the output
+// ranges from 0 to 2^31-1 but does not specify a macro to denote
+// this. We define RANDOM_MAX for cleanliness. We must omit the
+// definition for systems that have made the same choice. (Note that
+// random(3) is from 4.2BSD, and not specified by POSIX.)