5 POSIX specification: @url{http://www.opengroup.org/onlinepubs/9699919799/functions/dup2.html}
9 Portability problems fixed by Gnulib:
12 This function always returns 0 for success on some platforms:
16 This function can hang when duplicating an fd to itself on some platforms:
20 This function returns 0 for @code{dup2 (1, 1)} on some platforms:
24 This function may return @code{-EBADF} instead of @code{-1} on some platforms:
25 Linux releases between July 2008 and May 2009 (versions 2.6.27 to 2.6.29).
28 This function is missing on some older platforms.
31 Portability problems not fixed by Gnulib: