glibc/stdio-common/tst-fflush-all-input.c

95 lines
2.7 KiB
C

/* Test fflush (NULL) flushes input files (bug 32369).
Copyright (C) 2025 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
<https://www.gnu.org/licenses/>. */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <wchar.h>
#include <support/check.h>
#include <support/xstdio.h>
#include <support/xunistd.h>
int
do_test (void)
{
FILE *temp = tmpfile ();
TEST_VERIFY_EXIT (temp != NULL);
fprintf (temp, "abc");
TEST_COMPARE (fflush (temp), 0);
TEST_COMPARE (lseek (fileno (temp), 0, SEEK_SET), 0);
TEST_COMPARE (fgetc (temp), 'a');
TEST_COMPARE (fflush (NULL), 0);
TEST_COMPARE (lseek (fileno (temp), 0, SEEK_CUR), 1);
xfclose (temp);
/* Likewise, but in wide mode. */
temp = tmpfile ();
TEST_VERIFY_EXIT (temp != NULL);
fwprintf (temp, L"abc");
TEST_COMPARE (fflush (temp), 0);
TEST_COMPARE (lseek (fileno (temp), 0, SEEK_SET), 0);
TEST_COMPARE (fgetwc (temp), L'a');
TEST_COMPARE (fflush (NULL), 0);
TEST_COMPARE (lseek (fileno (temp), 0, SEEK_CUR), 1);
xfclose (temp);
/* Similar tests, but with the flush implicitly occurring on exit
(in a forked subprocess). */
temp = tmpfile ();
TEST_VERIFY_EXIT (temp != NULL);
pid_t pid = xfork ();
if (pid == 0)
{
fprintf (temp, "abc");
TEST_COMPARE (fflush (temp), 0);
TEST_COMPARE (lseek (fileno (temp), 0, SEEK_SET), 0);
TEST_COMPARE (fgetc (temp), 'a');
exit (EXIT_SUCCESS);
}
else
{
TEST_COMPARE (xwaitpid (pid, NULL, 0), pid);
TEST_COMPARE (lseek (fileno (temp), 0, SEEK_CUR), 1);
xfclose (temp);
}
temp = tmpfile ();
TEST_VERIFY_EXIT (temp != NULL);
pid = xfork ();
if (pid == 0)
{
fwprintf (temp, L"abc");
TEST_COMPARE (fflush (temp), 0);
TEST_COMPARE (lseek (fileno (temp), 0, SEEK_SET), 0);
TEST_COMPARE (fgetwc (temp), L'a');
exit (EXIT_SUCCESS);
}
else
{
TEST_COMPARE (xwaitpid (pid, NULL, 0), pid);
TEST_COMPARE (lseek (fileno (temp), 0, SEEK_CUR), 1);
xfclose (temp);
}
return 0;
}
#include <support/test-driver.c>