#define getdtablesize() (sysconf(_SC_OPEN_MAX))
If all else fails you can use the value of NOFILE in <sys/param.h>.
+If you are porting to a SysV-based OS, you should link in with a library
+that has BSD signals if possible, if not sudo will probably still work,
+but no promises.
+
+One other thing is that sudo expects to be able to use the uid_t and mode_t
+type definitions. Chances are you have uid_t, if not it is just what
+getuid(2) returns, you can add it in to sudo.h. If you have an older
+libc, you probably don't have mode_t. You can just compile with -DNO_MODE_T
+if umask(2) takes an int, if not, fix the definition in sudo.h.
+
If you port sudo to a new architecture, please send your changes to
sudo-bugs@cs.colorado.edu