int
main(void)
{
const off_t offset = 0xdefaceddeadbeefLL;
char *buf = tail_alloc(LEN);
struct iovec *iov = tail_alloc(sizeof(*iov));
iov->iov_base = buf;
iov->iov_len = LEN;
(void) close(0);
if (open("/dev/zero", O_RDONLY))
perror_msg_and_fail("open");
if (preadv(0, iov, 1, offset) != LEN)
perror_msg_and_fail("preadv");
printf("preadv(0, ");
print_iovec(iov, 1);
printf(", 1, %lld) = %u\n", (long long) offset, LEN);
if (preadv(0, iov, 1, -1) != -1)
perror_msg_and_fail("preadv");
printf("preadv(0, [{iov_base=%p, iov_len=%zu}], 1, -1) = "
"-1 EINVAL (%m)\n", iov->iov_base, iov->iov_len);
if (preadv(0, NULL, 1, -2) != -1)
perror_msg_and_fail("preadv");
printf("preadv(0, NULL, 1, -2) = -1 EINVAL (%m)\n");
if (preadv(0, iov, 0, -3) != -1)
perror_msg_and_fail("preadv");
printf("preadv(0, [], 0, -3) = -1 EINVAL (%m)\n");
static const char tmp[] = "preadv-tmpfile";
int fd = open(tmp, O_RDWR | O_CREAT | O_TRUNC, 0600);
if (fd < 0)
perror_msg_and_fail("open");
if (unlink(tmp))
perror_msg_and_fail("unlink");
static const char w[] = "0123456789abcde";
if (write(fd, w, LENGTH_OF(w)) != LENGTH_OF(w))
perror_msg_and_fail("write");
static const char r0_c[] = "01234567";
static const char r1_c[] = "89abcde";
const unsigned int r_len = (LENGTH_OF(w) + 1) / 2;
void *r0 = tail_alloc(r_len);
const struct iovec r0_iov_[] = {
{
.iov_base = r0,
.iov_len = r_len
}
};
int
main(void)
{
(void) close(0);
if (open("/dev/null", O_WRONLY))
perror_msg_and_fail("open");
char *buf = tail_alloc(LEN);
unsigned i;
for (i = 0; i < LEN; ++i)
buf[i] = i;
struct iovec *iov = tail_alloc(sizeof(*iov) * LEN);
for (i = 0; i < LEN; ++i) {
buf[i] = i;
iov[i].iov_base = &buf[i];
iov[i].iov_len = LEN - i;
}
const off_t offset = 0xdefaceddeadbeefLL;
long rc;
int written = 0;
for (i = 0; i < LEN; ++i) {
written += iov[i].iov_len;
if (pwritev(0, iov, i + 1, offset + i) != written)
perror_msg_and_fail("pwritev");
fputs("pwritev(0, ", stdout);
print_iovec(iov, i + 1, LEN);
printf(", %u, %lld) = %d\n",
i + 1, (long long) offset + i, written);
}
for (i = 0; i <= LEN; ++i) {
unsigned int n = LEN + 1 - i;
fputs("pwritev(0, ", stdout);
print_iovec(iov + i, n, LEN - i);
rc = pwritev(0, iov + i, n, offset + LEN + i);
printf(", %u, %lld) = %ld %s (%m)\n",
n, (long long) offset + LEN + i, rc, errno2name());
}
iov->iov_base = iov + LEN * 2;
rc = pwritev(0, iov, 1, -1);
printf("pwritev(0, [{%p, %d}], 1, -1) = %ld %s (%m)\n",
iov->iov_base, LEN, rc, errno2name());
iov += LEN;
rc = pwritev(0, iov, 42, -2);
printf("pwritev(0, %p, 42, -2) = %ld %s (%m)\n",
iov, rc, errno2name());
rc = pwritev(0, NULL, 1, -3);
printf("pwritev(0, NULL, 1, -3) = %ld %s (%m)\n",
rc, errno2name());
rc = pwritev(0, iov, 0, -4);
printf("pwritev(0, [], 0, -4) = %ld %s (%m)\n",
rc, errno2name());
puts("+++ exited with 0 +++");
return 0;
}