+
+- Please never use dup(). Use fcntl(fd, F_DUPFD_CLOEXEC, 3)
+ instead. For two reason: first, you want O_CLOEXEC set on the new fd
+ (see above). Second, dup() will happily duplicate your fd as 0, 1,
+ 2, i.e. stdin, stdout, stderr, should those fds be closed. Given the
+ special semantics of those fds, it's probably a good idea to avoid
+ them. F_DUPFD_CLOEXEC with "3" as parameter avoids them.