根据unix环境高级编程一书,我们知道管道在读端关闭时,写端继续写会引发SIGPIPE,而在网络(socket)连接的情况下,
如果接收端在发送端正在写的情况下关闭,发送端也会触发SIGPIPE,如果不处理该信号,那么程序就会崩溃。
测试代码:
服务端:
#include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <string.h> #include <errno.h> #include <fcntl.h> #include <sys/socket.h> #include <netinet/in.h> #define BUFFER_SIZE 8192 char buffer[BUFFER_SIZE]; void child_handle_send_recieve(int *client_fd); int main() { int rc; int socket_fd; int client_fd; int reuse = 1; socket_fd = socket(AF_INET, SOCK_STREAM, 0); if (socket_fd < 0) { perror("socket initial error"); } struct sockaddr_in addr; addr.sin_addr.s_addr = inet_addr("127.0.0.1"); addr.sin_family = AF_INET; addr.sin_port = htons(1989); rc = setsockopt(socket_fd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse)); if (rc < 0) { perror("set socket failed."); } rc = bind(socket_fd, (struct sockaddr*) &addr, sizeof(addr)); if (rc < 0) { perror("bind failed"); } rc = listen(socket_fd, 5); if (rc < 0) { perror("listen failed"); } while (1) { client_fd = rc = accept(socket_fd, NULL, 0); if (rc < 0) { perror("accept failed"); } int fork_rt; if ((fork_rt = fork()) < 0) { perror("fork error"); } else if (fork_rt > 0) { // parent close(client_fd); } else { // child process. close(socket_fd); child_handle_send_recieve(&client_fd); } } close(socket_fd); return 0; } void child_handle_send_recieve(int *client) { int client_fd = *client; int rc; memset(buffer, '\0', sizeof(buffer)); rc = recv(client_fd, buffer, BUFFER_SIZE, 0); if (rc < 0) { perror("receive failed"); } printf("received:%s\n", buffer); // close it now. close(client_fd); exit(0); }
客户端:
#include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <string.h> #include <sys/types.h> #include <sys/socket.h> #include <sys/ioctl.h> #include <sys/stat.h> #include <arpa/inet.h> #include <fcntl.h> #define BUFFER_SIZE 8192 int main(){ int socket_fd; struct sockaddr_in addr; char buf[BUFFER_SIZE]; int rc; socket_fd = socket(AF_INET,SOCK_STREAM,0); addr.sin_addr.s_addr = inet_addr("127.0.0.1"); addr.sin_family = AF_INET; addr.sin_port = htons(1989); rc = connect(socket_fd, (struct sockaddr*)&addr, sizeof(addr)); if(rc < 0){ perror("connect failed"); } bzero(buf, sizeof(buf)); strncpy(buf,"hello man.",11); while(1){ rc = send(socket_fd, buf,strlen(buf),0); if(rc < 0){ perror("send failed"); } } // never can print. printf("It's ok here????"); return 0; }
用gdb调试之,客户端截图: