SIGPIPE信号

 #include <sys/types.h>

 #include <sys/socket.h>

 #include <netinet/in.h>

 #include <arpa/inet.h>

 #include <unistd.h>

 #include <errno.h>

 #include <signal.h>

 #include <string.h>

 #include <assert.h>

 #include <iostream>

 void signal_func(int sig)

 {

     int saved_errno = errno;

     std::cout << "broken pipe!" << std::endl;

     errno = saved_errno;

 }

 int main()

 {

     struct sigaction sa;

     sa.sa_handler = signal_func;

     sigemptyset(&sa.sa_mask);

     sa.sa_flags = ;

     if (sigaction(SIGPIPE, &sa, NULL) < )

     {

         perror("cannot ignore SIGPIPE");

         return -;

     }

     int sockfd = socket(AF_INET, SOCK_STREAM, );

     uint16_t port = ;

     const char* ip= "192.168.16.105";

     assert(sockfd > );

     struct sockaddr_in sock_address;

     memset(&sock_address, , sizeof(sock_address));

     sock_address.sin_family = AF_INET;

     sock_address.sin_port = htons();

     inet_pton(AF_INET, ip, &(sock_address.sin_addr));

     socklen_t sock_len = sizeof(sock_address);

     int ret = connect(sockfd, (sockaddr*)&sock_address, sock_len);

     assert(ret != -);

     sleep(); // 在sleep之前断开服务端连接

     char send_buff[] = "hello server!";

     char recv_buff[] = {};

     ssize_t ret_1 = send(sockfd, send_buff, strlen(send_buff), ); // 收到对端FIN后依然可以发送成功　不过对端会响应RST

     if (ret_1 < )

     {

         std::cout << strerror(errno) << std::endl;

     }

     else

     {

         std::cout << "send success!" << std::endl;

     }

     ssize_t ret_2 = recv(sockfd, recv_buff, sizeof(recv_buff), );

     if(ret_2 == )

     {

         std::cout << "remote close connection" << std::endl;

     }

     ssize_t ret_3 = send(sockfd, send_buff, strlen(send_buff), ); // 这时再send会出错　并产生SIGPIPE信号　默认终止进程

     if(ret_3 < )

     {

         if (errno == EPIPE)

         {

             std::cout << strerror(errno) << std::endl;

         }

     }

     else

     {

         std::cout << "send success" << std::endl;

     }

     return ;

 }