truncate: New module.
[gnulib/ericb.git] / tests / test-unsetenv.c
blobd7d7d05a49e9eddb32ae6e48522ee221d7df6fc4
1 /* Tests of unsetenv.
2 Copyright (C) 2009-2017 Free Software Foundation, Inc.
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.
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.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
17 /* Written by Eric Blake <ebb9@byu.net>, 2009. */
19 #include <config.h>
21 #include <stdlib.h>
23 #include "signature.h"
24 SIGNATURE_CHECK (unsetenv, int, (char const *));
26 #include <errno.h>
27 #include <string.h>
28 #include <unistd.h>
30 #include "macros.h"
32 int
33 main (void)
35 char entry[] = "b=2";
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);
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
60 return 0;