/* Test of strerror() function.
   Copyright (C) 2007-2021 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, 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/>.  */

/* Written by Eric Blake <ebb9@byu.net>, 2007.  */

#include <config.h>

#include <string.h>

#include "signature.h"
SIGNATURE_CHECK (strerror, char *, (int));

#include <errno.h>

#include "macros.h"

int
main (void)
{
  char *str;

  errno = 0;
  str = strerror (EACCES);
  ASSERT (str);
  ASSERT (*str);
  ASSERT (errno == 0);

  errno = 0;
  str = strerror (ETIMEDOUT);
  ASSERT (str);
  ASSERT (*str);
  ASSERT (errno == 0);

  errno = 0;
  str = strerror (EOVERFLOW);
  ASSERT (str);
  ASSERT (*str);
  ASSERT (errno == 0);

  /* POSIX requires strerror (0) to succeed.  Reject use of "Unknown
     error", but allow "Success", "No error", or even Solaris' "Error
     0" which are distinct patterns from true out-of-range strings.
     http://austingroupbugs.net/view.php?id=382  */
  errno = 0;
  str = strerror (0);
  ASSERT (str);
  ASSERT (*str);
  ASSERT (errno == 0);
  ASSERT (strstr (str, "nknown") == NULL);
  ASSERT (strstr (str, "ndefined") == NULL);

  /* POSIX requires strerror to produce a non-NULL result for all
     inputs; as an extension, we also guarantee a non-empty result.
     Reporting EINVAL is optional.  */
  errno = 0;
  str = strerror (-3);
  ASSERT (str);
  ASSERT (*str);
  ASSERT (errno == 0 || errno == EINVAL);

  return 0;
}
