Linux c++(socket网络通信 & epoll 案例一)

 #include <stdio.h>                                                           
  #include <unistd.h>
  #include <stdlib.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <string.h>
  #include <sys/epoll.h>
 int main(int argc, char *argv[]){
      int fd[2];
      pipe(fd);
      pid_t pid = 0;
      pid=fork();
      if(pid == 0)
      {
          close(fd[0]);
          char buf[5];
          char ch='a';
          while(1)
          {
              sleep(3);
              memset(buf,ch++,sizeof(buf));
              write(fd[1],buf,strlen(buf)+1);
          }
      }else if(pid > 0)
      {
          close(fd[1]);
          // 创建树
          int epfd = epoll_create(1);
          struct epoll_event ev;
          ev.events = EPOLLIN;
          ev.data.fd = fd[0];
          struct epoll_event evs[1];
          epoll_ctl(epfd,EPOLL_CTL_ADD,fd[0],&ev);
          //监听
          while(1)
          {
              int n = epoll_wait(epfd,evs,1,-1);
              if (n == 1) {
                  char buf[1024] = {0};
                  int ret = read(fd[0],buf,sizeof(buf));
                  if(ret <= 0)
                  {
                      close(fd[0]);
                      epoll_ctl(epfd,EPOLL_CTL_DEL,fd[0],&ev);
                      break;
                  }else
                      printf("buf = %s\n",buf);
              }
          }
      }
      return 0;
  }