Worm/Passwords

[Guy Harris]

 >Just make it so that if the sticky bit is set on the directory's mode,
 >only the file's owner or root can unlink() it.  BSD already does this,

4.3BSD, anyway.  So does System V Release 3.2; both systems, as I
remember, also allow the owner of the *directory* to remove any entries
in it.  I think there's one other case where S5R3.2 allows an entry to
be removed but 4.3BSD doesn't, but I can't remember what it is.