请问：read函数如何被信号中断

windywater

用select的超时功能呢？类似：
fd_set set;
FD_ZERO(&set);
FD_SET(0, &set);
timeval timeout = { 3, 0 };
select(1, &set, NULL, NULL, &timeout);
if (FD_ISSET(0, &set))
    read(0, buf, 1024);