nuttx-apps/examples/elf/tests/errno/errno.c

/****************************************************************************
 * examples/elf/tests/errno/errno.c
 *
 *   Copyright (C) 2012 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>

/****************************************************************************
 * Included Files
 ****************************************************************************/

static const char g_nonexistent[] = "aflav-sautga-ay";

/****************************************************************************
 * Public Functions
 ****************************************************************************/

int main(int argc, char **argv)
{
  FILE *test_stream;

  /* Try using stdout and stderr explicitly.  These are global variables
   * exported from the base code.
   */

  fprintf(stdout, "Hello, World on stdout\n");
  fprintf(stderr, "Hello, World on stderr\n");

  /* Try opening a non-existent file using buffered IO. */

  test_stream = fopen(g_nonexistent, "r");
  if (test_stream)
    {
      fprintf(stderr, "Hmm... Delete \"%s\" and try this again\n",
              g_nonexistent);
      exit(1);
    }

  /* Now print the errno on stderr.  Errno is also a global
   * variable exported by the base code.
   */

  fprintf(stderr, "We failed to open \"%s!\" errno is %d\n",
          g_nonexistent, errno);

  return 0;
}