/* Tests of setenv.
   Copyright (C) 2009-2023 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/>.  */

/* Written by Eric Blake <ebb9@byu.net>, 2009.  */

#include <config.h>

#include <stdlib.h>

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

#include <errno.h>
#include <string.h>
#include <unistd.h>

#include "macros.h"

int
main (void)
{
  /* Test overwriting.  */
  ASSERT (setenv ("a", "==", -1) == 0);
  ASSERT (setenv ("a", "2", 0) == 0);
  ASSERT (strcmp (getenv ("a"), "==") == 0);

  /* Required to fail with EINVAL.  */
  errno = 0;
  ASSERT (setenv ("", "", 1) == -1);
  ASSERT (errno == EINVAL);
  errno = 0;
  ASSERT (setenv ("a=b", "", 0) == -1);
  ASSERT (errno == EINVAL);
#if 0
  /* glibc and gnulib's implementation guarantee this, but POSIX no
     longer requires it: http://austingroupbugs.net/view.php?id=185  */
  errno = 0;
  ASSERT (setenv (NULL, "", 0) == -1);
  ASSERT (errno == EINVAL);
#endif

  return 0;
}