5 POSIX specification:@* @url{https://pubs.opengroup.org/onlinepubs/9699919799/functions/dup2.html}
9 Portability problems fixed by Gnulib:
12 This function is declared in a different header file (namely, @code{<io.h>})
17 This function always returns 0 for success on some platforms:
21 This function can hang when duplicating an fd to itself on some platforms:
25 This function crashes when invoked with invalid arguments on some platforms:
26 Cygwin 1.7.17, MSVC 14.
29 This function crashes when invoked with valid arguments on some platforms:
33 This function fails with @code{EINVAL} when duplicating an fd to itself:
37 This function resets the @code{FD_CLOEXEC} flag when duplicating an fd
38 to itself on some platforms:
42 This function returns 0 for @code{dup2 (1, 1)} on some platforms:
46 This function may return @code{-EBADF} instead of @code{-1} on some platforms:
47 Linux releases between July 2008 and May 2009 (versions 2.6.27 to 2.6.29).
50 This function returns @code{EMFILE} instead of @code{EBADF} for
51 large targets, which interferes with using
52 @code{dup2(fd,fd)==fd)} as the minimal @code{EBADF} filter:
53 AIX 7.1, FreeBSD 6.1, Cygwin 1.5.
56 Portability problems not fixed by Gnulib: