1/* Copyright (C) 1991-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library 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 GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#include <stdio.h>
19
20#define TESTFILE OBJPFX "test.dat"
21
22static int
23do_test (void)
24{
25 FILE *fp;
26 int i, j;
27
28 puts (s: "\nFile seek test");
29 fp = fopen (TESTFILE, "w");
30 if (fp == NULL)
31 {
32 perror (TESTFILE);
33 return 1;
34 }
35
36 for (i = 0; i < 256; i++)
37 putc (c: i, stream: fp);
38 if (freopen (TESTFILE, "r", fp) != fp)
39 {
40 perror ("Cannot open file for reading");
41 return 1;
42 }
43
44 for (i = 1; i <= 255; i++)
45 {
46 printf (format: "%3d\n", i);
47 fseek (fp, (long) -i, SEEK_END);
48 if ((j = getc (stream: fp)) != 256 - i)
49 {
50 printf (format: "SEEK_END failed %d\n", j);
51 break;
52 }
53 if (fseek (fp, (long) i, SEEK_SET))
54 {
55 puts (s: "Cannot SEEK_SET");
56 break;
57 }
58 if ((j = getc (stream: fp)) != i)
59 {
60 printf (format: "SEEK_SET failed %d\n", j);
61 break;
62 }
63 if (fseek (fp, (long) i, SEEK_SET))
64 {
65 puts (s: "Cannot SEEK_SET");
66 break;
67 }
68 if (fseek (fp, (long) (i >= 128 ? -128 : 128), SEEK_CUR))
69 {
70 puts (s: "Cannot SEEK_CUR");
71 break;
72 }
73 if ((j = getc (stream: fp)) != (i >= 128 ? i - 128 : i + 128))
74 {
75 printf (format: "SEEK_CUR failed %d\n", j);
76 break;
77 }
78 }
79 fclose (fp);
80 remove (TESTFILE);
81
82 puts (s: (i > 255) ? "Test succeeded." : "Test FAILED!");
83 return (i > 255) ? 0 : 1;
84}
85
86#define TEST_FUNCTION do_test ()
87#include "../test-skeleton.c"
88

source code of glibc/stdio-common/test-fseek.c