1 files changed, 99 insertions, 0 deletions
diff --git a/gnulib-tests/test-isatty.c b/gnulib-tests/test-isatty.c
new file mode 100644
index 0000000..352365b
--- /dev/null
+++ b/gnulib-tests/test-isatty.c
@@ -0,0 +1,99 @@
+/* Test isatty() function.
+   Copyright (C) 2011-2023 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 <https://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+#include <unistd.h>
+
+#include "signature.h"
+SIGNATURE_CHECK (isatty, int, (int));
+
+#include <errno.h>
+#include <fcntl.h>
+
+#include "macros.h"
+
+/* The name of the "always silent" device.  */
+#if defined _WIN32 && ! defined __CYGWIN__
+/* Native Windows API.  */
+# define DEV_NULL "NUL"
+#else
+/* Unix API.  */
+# define DEV_NULL "/dev/null"
+#endif
+
+int
+main (void)
+{
+  const char *file = "test-isatty.txt";
+
+  /* Test behaviour for invalid file descriptors.  */
+  {
+    errno = 0;
+    ASSERT (isatty (-1) == 0);
+    ASSERT (errno == EBADF
+            || errno == 0 /* seen on IRIX 6.5, Solaris 10 */
+           );
+  }
+  {
+    close (99);
+    errno = 0;
+    ASSERT (isatty (99) == 0);
+    ASSERT (errno == EBADF
+            || errno == 0 /* seen on IRIX 6.5, Solaris 10 */
+           );
+  }
+
+  /* Test behaviour for regular files.  */
+  {
+    int fd;
+
+    fd = open (file, O_WRONLY|O_CREAT|O_TRUNC, 0644);
+    ASSERT (0 <= fd);
+    ASSERT (write (fd, "hello", 5) == 5);
+    ASSERT (close (fd) == 0);
+
+    fd = open (file, O_RDONLY);
+    ASSERT (0 <= fd);
+    ASSERT (! isatty (fd));
+    ASSERT (close (fd) == 0);
+  }
+
+  /* Test behaviour for pipes.  */
+  {
+    int fd[2];
+
+    ASSERT (pipe (fd) == 0);
+    ASSERT (! isatty (fd[0]));
+    ASSERT (! isatty (fd[1]));
+    ASSERT (close (fd[0]) == 0);
+    ASSERT (close (fd[1]) == 0);
+  }
+
+  /* Test behaviour for /dev/null.  */
+  {
+    int fd;
+
+    fd = open (DEV_NULL, O_RDONLY);
+    ASSERT (0 <= fd);
+    ASSERT (! isatty (fd));
+    ASSERT (close (fd) == 0);
+  }
+
+  ASSERT (unlink (file) == 0);
+
+  return 0;
+}