unplugged-system/external/ltp/testcases/kernel/syscalls/read/read04.c

61 lines
1.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (c) International Business Machines Corp., 2001
*/
/*\
* [Description]
*
* Testcase to check if read() returns the number of bytes read correctly.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <fcntl.h>
#include "tst_test.h"
static const char *fname = "test_file";
static const char palfa[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
#define PALFA_LEN (sizeof(palfa)-1)
static void verify_read(void)
{
int fd;
char prbuf[BUFSIZ];
fd = SAFE_OPEN(fname, O_RDONLY);
TEST(read(fd, prbuf, BUFSIZ));
if (TST_RET != PALFA_LEN) {
tst_res(TFAIL, "Bad read count - got %ld - expected %zu",
TST_RET, PALFA_LEN);
goto out;
}
if (memcmp(palfa, prbuf, PALFA_LEN)) {
tst_res(TFAIL, "read buffer not equal to write buffer");
goto out;
}
tst_res(TPASS, "read() data correctly");
out:
SAFE_CLOSE(fd);
}
static void setup(void)
{
int fd;
fd = SAFE_CREAT(fname, 0777);
SAFE_WRITE(SAFE_WRITE_ALL, fd, palfa, PALFA_LEN);
SAFE_CLOSE(fd);
}
static struct tst_test test = {
.needs_tmpdir = 1,
.setup = setup,
.test_all = verify_read,
};