1/* Verify that print functions return error when there is an I/O error.
2
3 Copyright (C) 2005-2022 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <https://www.gnu.org/licenses/>. */
19
20#include <errno.h>
21#include <error.h>
22#include <stdio.h>
23#include <stdlib.h>
24#include <unistd.h>
25
26
27static int
28do_test (void)
29{
30 char tmpl[] = "/tmp/tst-put-error.XXXXXX";
31 int fd = mkstemp (template: tmpl);
32 if (fd == -1)
33 error (EXIT_FAILURE, errno, format: "cannot create temporary file");
34 FILE *fp = fdopen (fd, "w");
35 if (fp == NULL)
36 error (EXIT_FAILURE, errno, format: "fdopen");
37
38 /* All of the tests below verify that flushing buffers result in failure of
39 the fprintf calls. We ensure that the buffer is flushed at the end of
40 each fprintf call by doing two things - setting the file pointer to
41 line-buffered so that it is flushed whenever it encounters a newline and
42 then ensuring that there is a newline in each of the format strings we
43 pass to fprintf. */
44
45 setlinebuf (fp);
46 close (fd: fd);
47 unlink (name: tmpl);
48
49 int n = fprintf (fp, "hello world\n");
50 printf (format: "fprintf = %d\n", n);
51 if (n >= 0)
52 error (EXIT_FAILURE, errnum: 0, format: "first fprintf succeeded");
53
54 n = fprintf (fp, "hello world\n");
55 printf (format: "fprintf = %d\n", n);
56 if (n >= 0)
57 error (EXIT_FAILURE, errnum: 0, format: "second fprintf succeeded");
58
59 /* Padded printing takes a different code path. */
60 n = fprintf (fp, "%100s\n", "foo");
61 printf (format: "fprintf = %d\n", n);
62 if (n >= 0)
63 error (EXIT_FAILURE, errnum: 0, format: "padded fprintf succeeded");
64
65 return 0;
66}
67
68#define TEST_FUNCTION do_test ()
69#include "../test-skeleton.c"
70

source code of glibc/stdio-common/tst-put-error.c