socket 断线重连

if(send(sockfd, serbuf, readlen, 0) < 0)//serbuf中有数据可以发送才会执行这条语句
{
    printf("serial to tcp send msg error: %s(errno: %d)\n", strerror(errno), errno);//服务端断掉，则发送失败。
    //exit(0);
    
    //断线重连        
    sleep(3);        
    close(sockfd);
    sockfd = socket(AF_INET, SOCK_STREAM, 0);//重新创建一个套接子，但描述符可能重复
    if (sockfd == -1) 
    {
        printf("recreate socket Error!!! Error # is %d. Exit!\n", errno);
        exit(-1);
    }
    printf("recreate sockfd is %d\n",sockfd);

    // connect to server
    while (-1 == connect(sockfd,(struct sockaddr *)(&servaddr), sizeof(servaddr))) 
    {
        printf("sockfd reconnect error: %s(errno: %d)\n",strerror(errno),errno);
        sleep(5);
    }                    
}

#include <signal.h>

signal(SIGPIPE, SIG_IGN);    // prevent exiting when we send data to closed socket