1 /* Test of freadahead() function.
2 Copyright (C) 2007-2018 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 Bruno Haible <bruno@clisp.org>, 2007. */
18
19 #include <config.h>
20
21 #include "freadahead.h"
22
23 #include <stdlib.h>
24 #include <unistd.h>
25
26 #include "macros.h"
27
28 int
main(int argc,char ** argv)29 main (int argc, char **argv)
30 {
31 int nbytes = atoi (argv[1]);
32 if (nbytes > 0)
33 {
34 void *buf = malloc (nbytes);
35 ASSERT (fread (buf, 1, nbytes, stdin) == nbytes);
36 }
37
38 if (nbytes == 0)
39 ASSERT (freadahead (stdin) == 0);
40 else
41 {
42 if (lseek (0, 0, SEEK_CUR) == nbytes)
43 /* An unbuffered stdio, such as BeOS or on uClibc compiled without
44 __STDIO_BUFFERS. */
45 ASSERT (freadahead (stdin) == 0);
46 else
47 {
48 /* Normal buffered stdio. */
49 size_t buffered;
50 int c, c2;
51
52 ASSERT (freadahead (stdin) != 0);
53 buffered = freadahead (stdin);
54
55 c = fgetc (stdin);
56 ASSERT (freadahead (stdin) == buffered - 1);
57 ungetc (c, stdin);
58 ASSERT (freadahead (stdin) == buffered);
59 c2 = fgetc (stdin);
60 ASSERT (c2 == c);
61 ASSERT (freadahead (stdin) == buffered - 1);
62
63 c = '@';
64 ungetc (c, stdin);
65 ASSERT (freadahead (stdin) == buffered);
66 c2 = fgetc (stdin);
67 ASSERT (c2 == c);
68 ASSERT (freadahead (stdin) == buffered - 1);
69 }
70 }
71
72 return 0;
73 }
74