glibc/stdio-common/tst-put-error.c
Siddhesh Poyarekar 2b766585f9 printf should return negative value on error
[BZ #11741]
Fixed bug where printf and family may return a spurious success when
printing padded formats.
2012-11-16 19:13:11 +05:30

60 lines
1.8 KiB
C

/* Verify that print functions return error when there is an I/O error.
Copyright (C) 2005-2012 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <error.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
static int
do_test (void)
{
char tmpl[] = "/tmp/tst-put-error.XXXXXX";
int fd = mkstemp (tmpl);
if (fd == -1)
error (EXIT_FAILURE, errno, "cannot create temporary file");
FILE *fp = fdopen (fd, "w");
if (fp == NULL)
error (EXIT_FAILURE, errno, "fdopen");
setlinebuf (fp);
close (fd);
unlink (tmpl);
int n = fprintf (fp, "hello world\n");
printf ("fprintf = %d\n", n);
if (n >= 0)
error (EXIT_FAILURE, 0, "first fprintf succeeded");
n = fprintf (fp, "hello world\n");
printf ("fprintf = %d\n", n);
if (n >= 0)
error (EXIT_FAILURE, 0, "second fprintf succeeded");
/* Padded printing takes a different code path. */
n = fprintf (fp, "%10000s", "foo");
printf ("fprintf = %d\n", n);
if (n >= 0)
error (EXIT_FAILURE, 0, "padded fprintf succeeded");
return 0;
}
#define TEST_FUNCTION do_test ()
#include "../test-skeleton.c"