多任务I/O之poll函数

#include <stdio.h>
#include <unistd.h>
#include <sys/poll.h>

int main(void){
    //要等待的文件的数组
    struct pollfd fds[2];
    int ret;

    fds[0].fd = STDIN_FILENO;//文件符
    fds[0].events = POLLIN;//等待的事件类型

    fds[1].fd = STDOUT_FILENO;
    fds[1].events = POLLOUT;

    ret = poll(fds, 1, 5000);
    if(ret == -1){
    perror("poll");
    return 1;
    }

    if(!ret){
    printf("time out\n");
    return 0;
    }

    if(fds[0].revents & POLLIN){
    printf("can read\n");
    }
    if(fds[1].revents & POLLOUT){
        printf("can write\n");
    }
    return 0;
}