socket 服务端如何获取IP地址？

    local_sock_fd = socket(AF_INET,SOCK_STREAM,0);
    if(local_sock_fd == -1){
        perror("ERROR socket()");
        return -1;
    }

    /*initialize socket addr*/
    local_sock_addr.sin_family = AF_INET;
    local_sock_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    local_sock_addr.sin_port = htons(LISTENING_PORT);

    int opt = 1;
    setsockopt(local_sock_fd,SOL_SOCKET,SO_REUSEADDR,&opt,sizeof(opt));

    if( bind(local_sock_fd,(struct sockaddr*)(&local_sock_addr),sizeof(struct sockaddr)) == -1){
        perror("ERROR bind()");
        return -1;
    }