2009-12-16 Eric Blake <ebb9@byu.net>
+ fcntl: support F_DUPFD_CLOEXEC on systems with fcntl
+ * modules/fcntl (Files): List new files.
+ (configure.ac): Run a test.
+ * m4/fcntl.m4 (gl_FUNC_FCNTL): New file.
+ * lib/fcntl.c (rpl_fcntl): Likewise.
+ * m4/fcntl_h.m4 (gl_FCNTL_H_DEFAULTS): Add witness defaults.
+ (gl_FCNTL_H): Always replace fcntl.h.
+ * modules/fcntl-h (Makefile.am): Substitute witnesses.
+ * lib/fcntl.in.h (fcntl): Declare replacement.
+ (F_DUPFD_CLOEXEC, GNULIB_defined_F_DUPFD_CLOEXEC): New macro when
+ needed, plus a witness.
+ * doc/posix-functions/fcntl.texi (fcntl): Document this.
+ * doc/posix-headers/fcntl.texi (fcntl.h): Likewise.
+ * tests/test-fcntl.c: New file.
+ * modules/fcntl-tests: Likewise.
+
binary-io: avoid potential compilation warning
* lib/binary-io.h [__DJGPP__]: Avoid null preprocessor
directives.
POSIX specification: @url{http://www.opengroup.org/onlinepubs/9699919799/functions/fcntl.html}
-Gnulib module: ---
+Gnulib module: fcntl
Portability problems fixed by Gnulib:
@itemize
+@item
+This function does not support @code{F_DUPFD_CLOEXEC} on some
+platforms:
+MacOS X 10.3, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, AIX 5.1, HP-UX 11,
+IRIX 6.5, OSF/1 5.1, Solaris 10, Cygwin 1.7.1, mingw, Interix 3.5,
+BeOS.
+Note that the gnulib replacement code is functional but not atomic.
@end itemize
Portability problems not fixed by Gnulib:
@samp{FD_CLOEXEC} is not defined on some platforms:
mingw.
+@item
+@samp{F_DUPFD_CLOEXEC} is not defined on some platforms:
+MacOS X 10.3, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, AIX 5.1, HP-UX 11,
+IRIX 6.5, OSF/1 5.1, Solaris 10, Cygwin 1.7.1, mingw, Interix 3.5,
+BeOS.
+
@item
@samp{AT_FDCWD}, @samp{AT_EACCESS}, @samp{AT_SYMLINK_NOFOLLOW},
@samp{AT_SYMLINK_FOLLOW}, and @samp{AT_REMOVEDIR}
on some platforms.
@item
-@samp{F_DUPFD}, @samp{F_DUPFD_CLOEXEC}, @samp{F_GETFD}, and
-@samp{F_SETFD} are not defined on some platforms:
-mingw
+@samp{F_DUPFD} and @samp{F_GETFD} are not defined on some platforms:
+mingw.
@item
-@samp{F_GETFL}, @samp{F_SETFL}, @samp{F_GETLK}, @samp{F_SETLK},
-@samp{F_SETLOKW}, @samp{F_GETOWN}, and @samp{F_SETOWN} are not defined
-on some platforms.
+@samp{F_SETFD}, @samp{F_GETFL}, @samp{F_SETFL}, @samp{F_GETLK},
+@samp{F_SETLK}, @samp{F_SETLOKW}, @samp{F_GETOWN}, and @samp{F_SETOWN}
+are not defined on some platforms:
+mingw.
@item
@samp{POSIX_FADV_DONTNEED}, @samp{POSIX_FADV_NOREUSE},
--- /dev/null
+/* Provide file descriptor control.
+
+ Copyright (C) 2009 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 Eric Blake <ebb9@byu.net>. */
+
+#include <config.h>
+
+/* Specification. */
+#include <fcntl.h>
+
+#include <errno.h>
+#include <stdarg.h>
+
+#if !HAVE_FCNTL
+# error not ported to mingw yet
+#endif
+#undef fcntl
+
+/* Perform the specified ACTION on the file descriptor FD, possibly
+ using the argument ARG further described below. This replacement
+ handles the following actions, and forwards all others on to the
+ native fcntl.
+
+ F_DUPFD_CLOEXEC - duplicate FD, with int ARG being the minimum
+ target fd. If successful, return the duplicate, which will not be
+ inheritable; otherwise return -1 and set errno. */
+
+int
+rpl_fcntl (int fd, int action, /* arg */...)
+{
+ va_list arg;
+ int result = -1;
+ va_start (arg, action);
+ switch (action)
+ {
+ case F_DUPFD_CLOEXEC:
+ {
+ int target = va_arg (arg, int);
+
+ /* Try the system call first, if the headers claim it exists
+ (that is, if GNULIB_defined_F_DUPFD_CLOEXEC is 0), since we
+ may be running with a glibc that has the macro but with an
+ older kernel that does not support it. Cache the
+ information on whether the system call really works, but
+ avoid caching failure if the corresponding F_DUPFD fails
+ for any reason. 0 = unknown, 1 = yes, -1 = no. */
+ static int have_dupfd_cloexec = GNULIB_defined_F_DUPFD_CLOEXEC ? -1 : 0;
+ if (0 <= have_dupfd_cloexec)
+ {
+ result = fcntl (fd, action, target);
+ if (0 <= result || errno != EINVAL)
+ have_dupfd_cloexec = 1;
+ else
+ {
+ result = fcntl (fd, F_DUPFD, target);
+ if (result < 0)
+ break;
+ have_dupfd_cloexec = -1;
+ }
+ }
+ else
+ result = fcntl (fd, F_DUPFD, target);
+ if (0 <= result && have_dupfd_cloexec == -1)
+ {
+ int flags = fcntl (result, F_GETFD);
+ if (flags < 0 || fcntl (result, F_SETFD, flags | FD_CLOEXEC) == -1)
+ {
+ int saved_errno = errno;
+ close (result);
+ errno = saved_errno;
+ result = -1;
+ }
+ }
+#if REPLACE_FCHDIR
+ if (0 <= result)
+ result = _gl_register_dup (fd, result);
+#endif
+ break;
+ } /* F_DUPFD_CLOEXEC */
+
+ default:
+ {
+ void *p = va_arg (arg, void *);
+ result = fcntl (fd, action, p);
+ break;
+ }
+ }
+ va_end (arg);
+ return result;
+}
extern "C" {
#endif
+#if @GNULIB_FCNTL@
+# if @REPLACE_FCNTL@
+# undef fcntl
+# define fcntl rpl_fcntl
+extern int fcntl (int fd, int action, ...);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef fcntl
+# define fcntl \
+ (GL_LINK_WARNING ("fcntl is not always POSIX compliant - " \
+ "use gnulib module fcntl for portability"), \
+ fcntl)
+#endif
+
#if @GNULIB_OPEN@
# if @REPLACE_OPEN@
# undef open
# define FD_CLOEXEC 1
#endif
+/* Fix up the supported F_* macros. Intentionally leave other F_*
+ macros undefined. */
+
+#ifndef F_DUPFD_CLOEXEC
+# define F_DUPFD_CLOEXEC 0x40000000
+/* Witness variable: 1 if gnulib defined F_DUPFD_CLOEXEC, 0 otherwise. */
+# define GNULIB_defined_F_DUPFD_CLOEXEC 1
+#else
+# define GNULIB_defined_F_DUPFD_CLOEXEC 0
+#endif
+
/* Fix up the O_* macros. */
#if !defined O_DIRECT && defined O_DIRECTIO
--- /dev/null
+# fcntl.m4 serial 1
+dnl Copyright (C) 2009 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.
+
+# For now, this module ensures that fcntl()
+# - supports or emulates F_DUPFD_CLOEXEC
+# Still to be ported to various platforms:
+# - supports F_DUPFD correctly
+# Still to be ported to mingw:
+# - F_GETFD, F_SETFD, F_DUPFD
+# - F_DUPFD_CLOEXEC
+# - F_GETFL, F_SETFL
+# - F_GETOWN, F_SETOWN
+# - F_GETLK, F_SETLK, F_SETLKW
+AC_DEFUN([gl_FUNC_FCNTL],
+[
+ dnl Persuade glibc to expose F_DUPFD_CLOEXEC.
+ AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+ AC_REQUIRE([gl_FCNTL_H_DEFAULTS])
+ AC_CHECK_FUNCS_ONCE([fcntl])
+ if test $ac_cv_func_fcntl = no; then
+ HAVE_FCNTL=0
+ else
+ AC_CACHE_CHECK([whether fcntl understands F_DUPFD_CLOEXEC],
+ [gl_cv_func_fcntl_f_dupfd_cloexec],
+ [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+#include <fcntl.h>
+#ifndef F_DUPFD_CLOEXEC
+choke me
+#endif
+ ]])],
+ [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+#ifdef __linux__
+/* The Linux kernel only added F_DUPFD_CLOEXEC in 2.6.24, so we always replace
+ it to support the semantics on older kernels that failed with EINVAL. */
+choke me
+#endif
+ ]])],
+ [gl_cv_func_fcntl_f_dupfd_cloexec=yes],
+ [gl_cv_func_fcntl_f_dupfd_cloexec="needs runtime check"])],
+ [gl_cv_func_fcntl_f_dupfd_cloexec=no])])
+ if test "$gl_cv_func_fcntl_f_dupfd_cloexec" != yes; then
+ REPLACE_FCNTL=1
+ AC_LIBOBJ([fcntl])
+ fi
+ fi
+])
-# serial 6
+# serial 7
# Configure fcntl.h.
dnl Copyright (C) 2006, 2007, 2009 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
AC_REQUIRE([gl_FCNTL_H_DEFAULTS])
AC_REQUIRE([gl_FCNTL_O_FLAGS])
gl_CHECK_NEXT_HEADERS([fcntl.h])
- FCNTL_H='fcntl.h'
- AC_SUBST([FCNTL_H])
])
# Test whether the flags O_NOATIME and O_NOFOLLOW actually work.
AC_DEFUN([gl_FCNTL_H_DEFAULTS],
[
+ GNULIB_FCNTL=0; AC_SUBST([GNULIB_FCNTL])
GNULIB_OPEN=0; AC_SUBST([GNULIB_OPEN])
GNULIB_OPENAT=0; AC_SUBST([GNULIB_OPENAT])
dnl Assume proper GNU behavior unless another module says otherwise.
HAVE_OPENAT=1; AC_SUBST([HAVE_OPENAT])
+ REPLACE_FCNTL=0; AC_SUBST([REPLACE_FCNTL])
REPLACE_OPEN=0; AC_SUBST([REPLACE_OPEN])
REPLACE_OPENAT=0; AC_SUBST([REPLACE_OPENAT])
])
Description:
-Placeholder for eventual fcntl() replacement.
+Support for fcntl() action F_DUPFD_CLOEXEC.
Files:
+m4/fcntl.m4
+lib/fcntl.c
Depends-on:
fcntl-h
configure.ac:
+gl_FUNC_FCNTL
+gl_FCNTL_MODULE_INDICATOR([fcntl])
Makefile.am:
gl_FCNTL_H
Makefile.am:
-BUILT_SOURCES += $(FCNTL_H)
+BUILT_SOURCES += fcntl.h
# We need the following in order to create <fcntl.h> when the system
# doesn't have one that works with the given compiler.
sed -e 's|@''INCLUDE_NEXT''@|$(INCLUDE_NEXT)|g' \
-e 's|@''PRAGMA_SYSTEM_HEADER''@|@PRAGMA_SYSTEM_HEADER@|g' \
-e 's|@''NEXT_FCNTL_H''@|$(NEXT_FCNTL_H)|g' \
+ -e 's|@''GNULIB_FCNTL''@|$(GNULIB_FCNTL)|g' \
-e 's|@''GNULIB_OPEN''@|$(GNULIB_OPEN)|g' \
-e 's|@''GNULIB_OPENAT''@|$(GNULIB_OPENAT)|g' \
+ -e 's|@''HAVE_OPENAT''@|$(HAVE_OPENAT)|g' \
+ -e 's|@''REPLACE_FCNTL''@|$(REPLACE_FCNTL)|g' \
-e 's|@''REPLACE_OPEN''@|$(REPLACE_OPEN)|g' \
-e 's|@''REPLACE_OPENAT''@|$(REPLACE_OPENAT)|g' \
- -e 's|@''HAVE_OPENAT''@|$(HAVE_OPENAT)|g' \
-e '/definition of GL_LINK_WARNING/r $(LINK_WARNING_H)' \
-e '/definition of _GL_ARG_NONNULL/r $(ARG_NONNULL_H)' \
< $(srcdir)/fcntl.in.h; \
--- /dev/null
+Files:
+tests/test-fcntl.c
+
+Depends-on:
+binary-io
+getdtablesize
+stdbool
+
+configure.ac:
+
+Makefile.am:
+TESTS += test-fcntl
+check_PROGRAMS += test-fcntl
--- /dev/null
+/* Test of fcntl(2).
+ Copyright (C) 2009 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 Eric Blake <ebb9@byu.net>, 2009. */
+
+#include <config.h>
+
+/* Specification. */
+#include <fcntl.h>
+
+/* Helpers. */
+#include <errno.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+/* Get declarations of the Win32 API functions. */
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
+#endif
+
+#include "binary-io.h"
+
+/* Use O_CLOEXEC if available, but test works without it. */
+#ifndef O_CLOEXEC
+# define O_CLOEXEC 0
+#endif
+
+#if !O_BINARY
+# define setmode(f,m) zero ()
+static int zero (void) { return 0; }
+#endif
+
+#define ASSERT(expr) \
+ do \
+ { \
+ if (!(expr)) \
+ { \
+ fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
+ fflush (stderr); \
+ abort (); \
+ } \
+ } \
+ while (0)
+
+/* Return true if FD is open. */
+static bool
+is_open (int fd)
+{
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+ /* On Win32, the initial state of unassigned standard file
+ descriptors is that they are open but point to an
+ INVALID_HANDLE_VALUE, and there is no fcntl. */
+ return (HANDLE) _get_osfhandle (fd) != INVALID_HANDLE_VALUE;
+#else
+# ifndef F_GETFL
+# error Please port fcntl to your platform
+# endif
+ return 0 <= fcntl (fd, F_GETFL);
+#endif
+}
+
+/* Return true if FD is open and inheritable across exec/spawn. */
+static bool
+is_inheritable (int fd)
+{
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+ /* On Win32, the initial state of unassigned standard file
+ descriptors is that they are open but point to an
+ INVALID_HANDLE_VALUE, and there is no fcntl. */
+ HANDLE h = (HANDLE) _get_osfhandle (fd);
+ DWORD flags;
+ if (h == INVALID_HANDLE_VALUE || GetHandleInformation (h, &flags) == 0)
+ return false;
+ return (flags & HANDLE_FLAG_INHERIT) != 0;
+#else
+# ifndef F_GETFD
+# error Please port fcntl to your platform
+# endif
+ int i = fcntl (fd, F_GETFD);
+ return 0 <= i && (i & FD_CLOEXEC) == 0;
+#endif
+}
+
+/* Return non-zero if FD is open in the given MODE, which is either
+ O_TEXT or O_BINARY. */
+static bool
+is_mode (int fd, int mode)
+{
+ int value = setmode (fd, O_BINARY);
+ setmode (fd, value);
+ return mode == value;
+}
+
+/* Since native fcntl can have more supported operations than our
+ replacement is aware of, and since various operations assign
+ different types to the vararg argument, a wrapper around fcntl must
+ be able to pass a vararg of unknown type on through to the original
+ fcntl. Make sure that this works properly: func1 behaves like the
+ original fcntl interpreting the vararg as an int or a pointer to a
+ struct, and func2 behaves like rpl_fcntl that doesn't know what
+ type to forward. */
+struct dummy_struct
+{
+ long filler;
+ int value;
+};
+static int
+func1 (int a, ...)
+{
+ va_list arg;
+ int i;
+ va_start (arg, a);
+ if (a < 4)
+ i = va_arg (arg, int);
+ else
+ {
+ struct dummy_struct *s = va_arg (arg, struct dummy_struct *);
+ i = s->value;
+ }
+ va_end (arg);
+ return i;
+}
+static int
+func2 (int a, ...)
+{
+ va_list arg;
+ void *p;
+ va_start (arg, a);
+ p = va_arg (arg, void *);
+ va_end (arg);
+ return func1 (a, p);
+}
+
+/* Ensure that all supported fcntl actions are distinct, and
+ usable in preprocessor expressions. */
+static void
+check_flags (void)
+{
+ switch (0)
+ {
+#ifdef F_DUPFD
+ case F_DUPFD:
+# if F_DUPFD
+# endif
+#endif
+
+#ifdef F_DUPFD_CLOEXEC
+ case F_DUPFD_CLOEXEC:
+# if F_DUPFD_CLOEXEC
+# endif
+#endif
+
+#ifdef F_GETFD
+ case F_GETFD:
+# if F_GETFD
+# endif
+#endif
+
+#ifdef F_SETFD
+ case F_SETFD:
+# if F_SETFD
+# endif
+#endif
+
+#ifdef F_GETFL
+ case F_GETFL:
+# if F_GETFL
+# endif
+#endif
+
+#ifdef F_SETFL
+ case F_SETFL:
+# if F_SETFL
+# endif
+#endif
+
+#ifdef F_GETOWN
+ case F_GETOWN:
+# if F_GETOWN
+# endif
+#endif
+
+#ifdef F_SETOWN
+ case F_SETOWN:
+# if F_SETOWN
+# endif
+#endif
+
+#ifdef F_GETLK
+ case F_GETLK:
+# if F_GETLK
+# endif
+#endif
+
+#ifdef F_SETLK
+ case F_SETLK:
+# if F_SETLK
+# endif
+#endif
+
+#ifdef F_SETLKW
+ case F_SETLKW:
+# if F_SETLKW
+# endif
+#endif
+
+ ;
+ }
+}
+
+int
+main (int argc, char **argv)
+{
+ const char *file = "test-fcntl.tmp";
+ int fd;
+
+ /* Sanity check that rpl_fcntl is likely to work. */
+ ASSERT (func2 (1, 2) == 2);
+ ASSERT (func2 (2, -2) == -2);
+ ASSERT (func2 (3, 0x80000000) == 0x80000000);
+ {
+ struct dummy_struct s = { 0L, 4 };
+ ASSERT (func2 (4, &s) == 4);
+ }
+ check_flags ();
+
+#if HAVE_FCNTL
+
+ /* Assume std descriptors were provided by invoker, and ignore fds
+ that might have been inherited. */
+ fd = creat (file, 0600);
+ ASSERT (STDERR_FILENO < fd);
+ close (fd + 1);
+ close (fd + 2);
+
+ /* For F_DUPFD*, the source must be valid. */
+ errno = 0;
+ ASSERT (fcntl (-1, F_DUPFD, 0) == -1);
+ ASSERT (errno == EBADF);
+ errno = 0;
+ ASSERT (fcntl (fd + 1, F_DUPFD, 0) == -1);
+ ASSERT (errno == EBADF);
+ errno = 0;
+ ASSERT (fcntl (10000000, F_DUPFD, 0) == -1);
+ ASSERT (errno == EBADF);
+ errno = 0;
+ ASSERT (fcntl (-1, F_DUPFD_CLOEXEC, 0) == -1);
+ ASSERT (errno == EBADF);
+ errno = 0;
+ ASSERT (fcntl (fd + 1, F_DUPFD_CLOEXEC, 0) == -1);
+ ASSERT (errno == EBADF);
+ errno = 0;
+ ASSERT (fcntl (10000000, F_DUPFD_CLOEXEC, 0) == -1);
+ ASSERT (errno == EBADF);
+
+ /* For F_DUPFD*, the destination must be valid. */
+ ASSERT (getdtablesize () < 10000000);
+ errno = 0;
+ ASSERT (fcntl (fd, F_DUPFD, -1) == -1);
+ ASSERT (errno == EINVAL);
+ errno = 0;
+ ASSERT (fcntl (fd, F_DUPFD, 10000000) == -1);
+ ASSERT (errno == EINVAL);
+ ASSERT (getdtablesize () < 10000000);
+ errno = 0;
+ ASSERT (fcntl (fd, F_DUPFD_CLOEXEC, -1) == -1);
+ ASSERT (errno == EINVAL);
+ errno = 0;
+ ASSERT (fcntl (fd, F_DUPFD_CLOEXEC, 10000000) == -1);
+ ASSERT (errno == EINVAL);
+
+ /* For F_DUPFD*, check for correct inheritance, as well as
+ preservation of text vs. binary. */
+ setmode (fd, O_BINARY);
+ ASSERT (is_open (fd));
+ ASSERT (!is_open (fd + 1));
+ ASSERT (!is_open (fd + 2));
+ ASSERT (is_inheritable (fd));
+ ASSERT (is_mode (fd, O_BINARY));
+
+ ASSERT (fcntl (fd, F_DUPFD, fd) == fd + 1);
+ ASSERT (is_open (fd));
+ ASSERT (is_open (fd + 1));
+ ASSERT (!is_open (fd + 2));
+ ASSERT (is_inheritable (fd + 1));
+ ASSERT (is_mode (fd, O_BINARY));
+ ASSERT (is_mode (fd + 1, O_BINARY));
+ ASSERT (close (fd + 1) == 0);
+
+ ASSERT (fcntl (fd, F_DUPFD_CLOEXEC, fd + 2) == fd + 2);
+ ASSERT (is_open (fd));
+ ASSERT (!is_open (fd + 1));
+ ASSERT (is_open (fd + 2));
+ ASSERT (is_inheritable (fd));
+ ASSERT (!is_inheritable (fd + 2));
+ ASSERT (is_mode (fd, O_BINARY));
+ ASSERT (is_mode (fd + 2, O_BINARY));
+ ASSERT (close (fd) == 0);
+
+ setmode (fd + 2, O_TEXT);
+ ASSERT (fcntl (fd + 2, F_DUPFD, fd + 1) == fd + 1);
+ ASSERT (!is_open (fd));
+ ASSERT (is_open (fd + 1));
+ ASSERT (is_open (fd + 2));
+ ASSERT (is_inheritable (fd + 1));
+ ASSERT (!is_inheritable (fd + 2));
+ ASSERT (is_mode (fd + 1, O_TEXT));
+ ASSERT (is_mode (fd + 2, O_TEXT));
+ ASSERT (close (fd + 1) == 0);
+
+ ASSERT (fcntl (fd + 2, F_DUPFD_CLOEXEC, 0) == fd);
+ ASSERT (is_open (fd));
+ ASSERT (!is_open (fd + 1));
+ ASSERT (is_open (fd + 2));
+ ASSERT (!is_inheritable (fd));
+ ASSERT (!is_inheritable (fd + 2));
+ ASSERT (is_mode (fd, O_TEXT));
+ ASSERT (is_mode (fd + 2, O_TEXT));
+ ASSERT (close (fd + 2) == 0);
+
+ /* Cleanup. */
+ ASSERT (close (fd) == 0);
+ ASSERT (unlink (file) == 0);
+
+#endif /* HAVE_FCNTL */
+
+ return 0;
+}