1 /* Common definitions for pread and pwrite.
2 Copyright (C) 2016-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19 #include <errno.h>
20 #include <error.h>
21 #include <string.h>
22 #include <unistd.h>
23 #include <sys/stat.h>
24
25 static void do_prepare (void);
26 #define PREPARE(argc, argv) do_prepare ()
27 static int do_test (void);
28 #define TEST_FUNCTION do_test ()
29
30 /* This defines the `main' function and some more. */
31 #include <test-skeleton.c>
32
33 /* These are for the temporary file we generate. */
34 static char *name;
35 static int fd;
36
37 static void
do_prepare(void)38 do_prepare (void)
39 {
40 fd = create_temp_file ("tst-preadwrite.", &name);
41 if (fd == -1)
42 error (EXIT_FAILURE, errno, "cannot create temporary file");
43 }
44
45
46 static ssize_t
do_test_with_offset(off_t offset)47 do_test_with_offset (off_t offset)
48 {
49 char buf[1000];
50 char res[1000];
51 int i;
52 ssize_t ret;
53
54 memset (buf, '\0', sizeof (buf));
55 memset (res, '\xff', sizeof (res));
56
57 if (write (fd, buf, sizeof (buf)) != sizeof (buf))
58 error (EXIT_FAILURE, errno, "during write");
59
60 for (i = 100; i < 200; ++i)
61 buf[i] = i;
62 ret = pwrite (fd, buf + 100, 100, offset + 100);
63 if (ret == -1)
64 error (EXIT_FAILURE, errno, "during pwrite");
65
66 for (i = 450; i < 600; ++i)
67 buf[i] = i;
68 ret = pwrite (fd, buf + 450, 150, offset + 450);
69 if (ret == -1)
70 error (EXIT_FAILURE, errno, "during pwrite");
71
72 ret = pread (fd, res, sizeof (buf) - 50, offset + 50);
73 if (ret == -1)
74 error (EXIT_FAILURE, errno, "during pread");
75
76 if (memcmp (buf + 50, res, ret) != 0)
77 {
78 printf ("error: read of pread != write of pwrite\n");
79 return -1;
80 }
81
82 return ret;
83 }
84