@node stdin
@subsection @code{stdin}
@findex stdin

POSIX specification:@* @url{https://pubs.opengroup.org/onlinepubs/9799919799/functions/stdin.html}

Gnulib module: ---

Portability problems fixed by Gnulib:
@itemize
@end itemize

Portability problems not fixed by Gnulib:
@itemize
@item
stdin is created in 32-bit mode instead of 64-bit mode: Cygwin 1.5.x.
One workaround is to use freopen(NULL, ``r'', stdin) on Cygwin 1.5.21
or newer.  Another is to use the gnulib ftello module and do
ftello(stdin).
@item
POSIX states that a setuid application can guarantee that fd 0 is
open, but some systems guarantee this even for non-setuid programs.
If an application is executed with fd 0 closed, use of @code{stdin}
can affect an unrelated file that happened to be assigned to fd 0.
The gnulib @code{xstdopen} or the *-safer modules may be used to
guarantee that fd 0 stays
reserved for @code{stdin}.
@end itemize
