5 POSIX specification: @url{http://www.opengroup.org/onlinepubs/9699919799/functions/fclose.html}
9 Portability problems fixed by Gnulib:
12 On Windows platforms (excluding Cygwin), @code{socket} and @code{accept}
13 followed by @code{fdopen} do not return streams that can be closed by
17 Portability problems not fixed by Gnulib:
20 On Windows platforms (excluding Cygwin), this function does not set @code{errno}