doc: Mention reason for replacement on glibc/Linux systems. * doc/posix-functions/dprintf.texi: Mention the problem with special 'long double' values. * doc/posix-functions/fprintf.texi: Likewise. * doc/posix-functions/printf.texi: Likewise. * doc/posix-functions/snprintf.texi: Likewise. * doc/posix-functions/sprintf.texi: Likewise. * doc/posix-functions/vdprintf.texi: Likewise. * doc/posix-functions/vfprintf.texi: Likewise. * doc/posix-functions/vprintf.texi: Likewise. * doc/posix-functions/vsnprintf.texi: Likewise. * doc/posix-functions/vsprintf.texi: Likewise. * doc/posix-functions/fcntl.texi: Add glibc/Linux to the list of platforms with F_DUPFD_CLOEXEC problems. * doc/posix-functions/glob.texi: Mention which platforms are affected by the problem with symbolic links. * doc/posix-functions/linkat.texi: Mention the problem with AT_SYMLINK_FOLLOW on Linux.

@node ttyname
@section @code{ttyname}
@findex ttyname

POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/ttyname.html}

Gnulib module: ---

Portability problems fixed by Gnulib:
@itemize
@end itemize

Portability problems not fixed by Gnulib:
@itemize
@item
This function is missing on some platforms:
mingw, MSVC 9.
@end itemize