1 files changed, 73 insertions, 0 deletions
diff --git a/gnulib-tests/test-read.c b/gnulib-tests/test-read.c
new file mode 100644
index 0000000..872f34c
--- /dev/null
+++ b/gnulib-tests/test-read.c
@@ -0,0 +1,73 @@
+/* Test the read() function.
+   Copyright (C) 2011-2020 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 (read, ssize_t, (int, void *, size_t));
+
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+
+#include "macros.h"
+
+int
+main (void)
+{
+  const char *filename = "test-read.tmp";
+  int fd;
+
+  /* Create a file with a simple contents.  */
+  fd = open (filename, O_CREAT | O_WRONLY, 0600);
+  ASSERT (fd >= 0);
+  ASSERT (write (fd, "Hello World", 11) == 11);
+  ASSERT (close (fd) == 0);
+
+  /* Read from the middle of the file.  */
+  fd = open (filename, O_RDONLY);
+  ASSERT (fd >= 0);
+  ASSERT (lseek (fd, 6, SEEK_SET) == 6);
+  {
+    char buf[10];
+    ssize_t ret = read (fd, buf, 10);
+    ASSERT (ret == 5);
+    ASSERT (memcmp (buf, "World", 5) == 0);
+  }
+  ASSERT (close (fd) == 0);
+
+  /* Test behaviour for invalid file descriptors.  */
+  {
+    char byte;
+    errno = 0;
+    ASSERT (read (-1, &byte, 1) == -1);
+    ASSERT (errno == EBADF);
+  }
+  {
+    char byte;
+    close (99);
+    errno = 0;
+    ASSERT (read (99, &byte, 1) == -1);
+    ASSERT (errno == EBADF);
+  }
+
+  /* Clean up.  */
+  unlink (filename);
+
+  return 0;
+}