LBUF_SIZE
static unsigned char buf[LBUF_SIZE];
assert(bytes_read < LBUF_SIZE - 1);
rv = read(fd, buf + bytes_read, LBUF_SIZE - bytes_read - 1);
assert(bytes_read <= LBUF_SIZE - 1);
buf[LBUF_SIZE - 1] = '\0';
if (bytes_read < LBUF_SIZE - 1)
assert(len <= LBUF_SIZE);