1 /* Test the write() function.
2 Copyright (C) 2011-2020 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 #include <config.h>
18
19 #include <unistd.h>
20
21 #include "signature.h"
22 SIGNATURE_CHECK (write, ssize_t, (int, const void *, size_t));
23
24 #include <errno.h>
25 #include <fcntl.h>
26 #include <string.h>
27
28 #include "macros.h"
29
30 int
main(void)31 main (void)
32 {
33 const char *filename = "test-write.tmp";
34 int fd;
35
36 /* Create a file with a simple contents. */
37 fd = open (filename, O_CREAT | O_WRONLY, 0600);
38 ASSERT (fd >= 0);
39 ASSERT (write (fd, "Hello World", 11) == 11);
40 ASSERT (close (fd) == 0);
41
42 /* Write into the middle of the file. */
43 fd = open (filename, O_WRONLY);
44 ASSERT (fd >= 0);
45 ASSERT (lseek (fd, 6, SEEK_SET) == 6);
46 ASSERT (write (fd, "fascination", 11) == 11);
47
48 /* Verify the contents of the file. */
49 {
50 char buf[64];
51 int rfd = open (filename, O_RDONLY);
52 ASSERT (rfd >= 0);
53 ASSERT (read (rfd, buf, sizeof (buf)) == 17);
54 ASSERT (close (rfd) == 0);
55 ASSERT (memcmp (buf, "Hello fascination", 17) == 0);
56 }
57
58 ASSERT (close (fd) == 0);
59
60 /* Test behaviour for invalid file descriptors. */
61 {
62 char byte = 'x';
63 errno = 0;
64 ASSERT (write (-1, &byte, 1) == -1);
65 ASSERT (errno == EBADF);
66 }
67 {
68 char byte = 'x';
69 close (99);
70 errno = 0;
71 ASSERT (write (99, &byte, 1) == -1);
72 ASSERT (errno == EBADF);
73 }
74
75 /* Clean up. */
76 unlink (filename);
77
78 return 0;
79 }
80