1 files changed, 121 insertions, 0 deletions
diff --git a/tests/test-dup2.c b/tests/test-dup2.c
new file mode 100644
index 00000000..2009aaa2
--- /dev/null
+++ b/tests/test-dup2.c
@@ -0,0 +1,121 @@
+/* Test duplicating file descriptors.
+   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>
+
+#include <unistd.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+/* Get declarations of the Win32 API functions.  */
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
+#endif
+
+#define ASSERT(expr) \
+  do									     \
+    {									     \
+      if (!(expr))							     \
+        {								     \
+          fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
+          fflush (stderr);						     \
+          abort ();							     \
+        }								     \
+    }									     \
+  while (0)
+
+/* Return non-zero if FD is open.  */
+static int
+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
+}
+
+int
+main ()
+{
+  const char *file = "test-dup2.tmp";
+  char buffer[1];
+  int fd = open (file, O_CREAT | O_RDWR, 0600);
+
+  /* Assume std descriptors were provided by invoker.  */
+  ASSERT (STDERR_FILENO < fd);
+  ASSERT (is_open (fd));
+  /* Ignore any other fd's leaked into this process.  */
+  close (fd + 1);
+  close (fd + 2);
+  ASSERT (!is_open (fd + 1));
+  ASSERT (!is_open (fd + 2));
+
+  /* Assigning to self must be a no-op.  */
+  ASSERT (dup2 (fd, fd) == fd);
+  ASSERT (is_open (fd));
+
+  /* If the source is not open, then the destination is unaffected.  */
+  errno = 0;
+  ASSERT (dup2 (fd + 1, fd + 1) == -1);
+  ASSERT (errno == EBADF);
+  ASSERT (!is_open (fd + 1));
+  errno = 0;
+  ASSERT (dup2 (fd + 1, fd) == -1);
+  ASSERT (errno == EBADF);
+  ASSERT (is_open (fd));
+
+  /* The destination must be valid.  */
+  errno = 0;
+  ASSERT (dup2 (fd, -2) == -1);
+  ASSERT (errno == EBADF);
+
+  /* Using dup2 can skip fds.  */
+  ASSERT (dup2 (fd, fd + 2) == fd + 2);
+  ASSERT (is_open (fd));
+  ASSERT (!is_open (fd + 1));
+  ASSERT (is_open (fd + 2));
+
+  /* Prove that dup2 closes the previous occupant of a fd.  */
+  ASSERT (open ("/dev/null", O_WRONLY, 0600) == fd + 1);
+  ASSERT (dup2 (fd + 1, fd) == fd);
+  ASSERT (close (fd + 1) == 0);
+  ASSERT (write (fd, "1", 1) == 1);
+  ASSERT (dup2 (fd + 2, fd) == fd);
+  ASSERT (write (fd + 2, "2", 1) == 1);
+  ASSERT (lseek (fd, SEEK_SET, 0) == 0);
+  ASSERT (read (fd, buffer, 1) == 1);
+  ASSERT (*buffer == '2');
+
+  /* Clean up.  */
+  ASSERT (close (fd + 2) == 0);
+  ASSERT (close (fd) == 0);
+  ASSERT (unlink (file) == 0);
+
+  return 0;
+}