# Things you might add to DEFS:
# -DSTDC_HEADERS If you have ANSI C headers and libraries.
# -DHAVE_UNISTD_H If you have unistd.h.
+# -DHAVE_STRING_H If you don't have ANSI C headers but have string.h.
# -DHAVE_LIMITS_H If you have limits.h.
# -DBSD42 If you have sys/dir.h (unless you use -DPOSIX),
# sys/file.h, and st_blocks in `struct stat'.
-# -DUSG If you have System V/ANSI C string
-# and memory functions and headers,
-# fcntl.h, getcwd, no valloc,
-# and ndir.h (unless you use -DDIRENT).
-# -DDIRENT If USG and you have dirent.h instead of ndir.h.
+# -DDIRENT If you have dirent.h.
+# -DSYSNDIR Old Xenix systems (sys/ndir.h).
+# -DSYSDIR Old BSD systems (sys/dir.h).
+# -DNDIR Old System V systems (ndir.h).
# -DMAJOR_IN_MKDEV If major, minor, makedev defined in sys/mkdev.h.
# -DMAJOR_IN_SYSMACROS If major, minor, makedev defined in sys/sysmacros.h.
# -DRETSIGTYPE=int If your signal handlers return int, not void.
# -DHAVE_MKDIR If you have mkdir and rmdir system calls.
# -DHAVE_MKNOD If you have mknod system call.
# -DHAVE_RENAME If you have rename system call.
+# -DHAVE_GETCWD If not POSIX.1 but have getcwd function.
# -DHAVE_FTRUNCATE If you have ftruncate system call.
# -DV7 On Version 7 Unix (not tested in a long time).
# -DEMUL_OPEN3 If you lack a 3-argument version of open, and want