1  /* Tests of unsetenv.
       2     Copyright (C) 2009-2021 Free Software Foundation, Inc.
       3  
       4     This program is free software: you can redistribute it and/or modify
       5     it under the terms of the GNU General Public License as published by
       6     the Free Software Foundation; either version 3 of the License, or
       7     (at your option) any later version.
       8  
       9     This program is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      12     GNU General Public License for more details.
      13  
      14     You should have received a copy of the GNU General Public License
      15     along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
      16  
      17  /* Written by Eric Blake <ebb9@byu.net>, 2009.  */
      18  
      19  #include <config.h>
      20  
      21  #include <stdlib.h>
      22  
      23  #include "signature.h"
      24  SIGNATURE_CHECK (unsetenv, int, (char const *));
      25  
      26  #include <errno.h>
      27  #include <string.h>
      28  #include <unistd.h>
      29  
      30  #include "macros.h"
      31  
      32  int
      33  main (void)
      34  {
      35    char entry[] = "b=2";
      36  
      37    /* Test removal when multiple entries present.  */
      38    ASSERT (putenv ((char *) "a=1") == 0);
      39    ASSERT (putenv (entry) == 0);
      40    entry[0] = 'a'; /* Unspecified what getenv("a") would be at this point.  */
      41    ASSERT (unsetenv ("a") == 0); /* Both entries will be removed.  */
      42    ASSERT (getenv ("a") == NULL);
      43    ASSERT (unsetenv ("a") == 0);
      44  
      45    /* Required to fail with EINVAL.  */
      46    errno = 0;
      47    ASSERT (unsetenv ("") == -1);
      48    ASSERT (errno == EINVAL);
      49    errno = 0;
      50    ASSERT (unsetenv ("a=b") == -1);
      51    ASSERT (errno == EINVAL);
      52  #if 0
      53    /* glibc and gnulib's implementation guarantee this, but POSIX no
      54       longer requires it: http://austingroupbugs.net/view.php?id=185  */
      55    errno = 0;
      56    ASSERT (unsetenv (NULL) == -1);
      57    ASSERT (errno == EINVAL);
      58  #endif
      59  
      60    return 0;
      61  }