poll 函数简单介绍
#include <fcntl.h>#include <stdio.h>#include <unistd.h>#include <stdlib.h>#include <string.h>#include <time.h>#include <errno.h>#include <poll.h>#define MAX_BUFFER_SIZE 1024#define IN_FILES 3#define TIME_DELAY 60*5#define MAX(a,b) ((a>b)?(a):(b))int main(int argc ,char **argv){struct pollfd fds[IN_FILES];char buf[MAX_BUFFER_SIZE];int i,res,real_read, maxfd;fds[0].fd = 0;if((fds[1].fd=open("data1",O_RDONLY|O_NONBLOCK)) < 0){fprintf(stderr,"open data1 error:%s",strerror(errno));return 1;}if((fds[2].fd=open("data2",O_RDONLY|O_NONBLOCK)) < 0){fprintf(stderr,"open data2 error:%s",strerror(errno));return 1;}for (i = 0; i < IN_FILES; i++){fds[i].events = POLLIN;}while(fds[0].events || fds[1].events || fds[2].events){if (poll(fds, IN_FILES, TIME_DELAY) <= 0){printf("Poll error\n");return 1;}for (i = 0; i< IN_FILES; i++){if (fds[i].revents){memset(buf, 0, MAX_BUFFER_SIZE);real_read = read(fds[i].fd, buf, MAX_BUFFER_SIZE);if (real_read < 0){if (errno != EAGAIN){return 1;}}else if (!real_read){close(fds[i].fd);fds[i].events = 0;}else{if (i == 0){if ((buf[0] == 'q') || (buf[0] == 'Q')){return 1;}}else{buf[real_read] = '\0';printf("%s", buf);}}}}}exit(0);}
