stdopen: remove unused code

* m4/stdopen.m4: Delete now-unused file.
* lib/stdopen.h: Likewise.
* lib/stdopen.c: Likewise.

lib/stdopen.c

@@ -1,74 +0,0 @@
-/* stdopen.c - ensure that the three standard file descriptors are in use
-
-   Copyright (C) 2005, 2006 Free Software Foundation, Inc.
-
-   This program is free software: you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation, either version 3 of the License, or
-   (at your option) any later version.
-
-   This program is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-   GNU General Public License for more details.
-
-   You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
-
-/* Written by Paul Eggert and Jim Meyering.  */
-
-#include <config.h>
-
-#include "stdopen.h"
-
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <unistd.h>
-#include <errno.h>
-
-/* Try to ensure that all of the standard file numbers (0, 1, 2)
-   are in use.  Without this, each application would have to guard
-   every call to open, dup, fopen, etc. with tests to ensure they
-   don't use one of the special file numbers when opening a file.
-   Return false if at least one of the file descriptors is initially
-   closed and an attempt to reopen it fails.  Otherwise, return true.  */
-bool
-stdopen (void)
-{
-  int fd;
-  bool ok = true;
-
-  for (fd = 0; fd <= 2; fd++)
-    {
-      if (fcntl (fd, F_GETFD) < 0)
-	{
-	  if (errno != EBADF)
-	    ok = false;
-	  else
-	    {
-	      static const int contrary_mode[]
-		= { O_WRONLY, O_RDONLY, O_RDONLY };
-	      int mode = contrary_mode[fd];
-	      int new_fd;
-	      /* Open /dev/null with the contrary mode so that the typical
-		 read (stdin) or write (stdout, stderr) operation will fail.
-		 With descriptor 0, we can do even better on systems that
-		 have /dev/full, by opening that write-only instead of
-		 /dev/null.  The only drawback is that a write-provoked
-		 failure comes with a misleading errno value, ENOSPC.  */
-	      if (mode == O_RDONLY
-		  || (new_fd = open ("/dev/full", mode) != fd))
-		new_fd = open ("/dev/null", mode);
-	      if (new_fd != fd)
-		{
-		  if (0 <= new_fd)
-		    close (new_fd);
-		  ok = false;
-		}
-	    }
-	}
-    }
-
-  return ok;
-}

lib/stdopen.h

@@ -1,16 +0,0 @@
-#ifndef STDOPEN_H
-# define STDOPEN_H 1
-
-# include <stdbool.h>
-
-# ifdef __cplusplus
-extern "C" {
-# endif
-
-bool stdopen (void);
-
-# ifdef __cplusplus
-}
-# endif
-
-#endif

m4/stdopen.m4

@@ -1,13 +0,0 @@
-#serial 1
-dnl Copyright (C) 2005 Free Software Foundation, Inc.
-dnl This file is free software; the Free Software Foundation
-dnl gives unlimited permission to copy and/or distribute it,
-dnl with or without modifications, as long as this notice is preserved.
-
-AC_DEFUN([gl_STDOPEN],
-[
-  AC_LIBSOURCES([stdopen.c, stdopen.h])
-  AC_LIBOBJ([stdopen])
-
-  dnl Prerequisites.
-])