在服务器多进程版本的基础上，使用管道来向一个子进程发送接收到的数据，该子进程将接收到的数据保存到文件中。客户端代码不变。

服务器代码

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <unistd.h>
#include <csignal>
#include <sys/wait.h>
#include <arpa/inet.h>
#include <sys/socket.h>const int BUF_SIZE = 30;void error_handling(const char *messgae);
void read_childproc(int sig);// 接收一个参数，argv[1]为端口号
int main(int argc, char *argcv[]) {int server_sock, client_sock;struct sockaddr_in server_addr, client_addr;int fds[2]; // 管道描述符pid_t pid;struct sigaction act;socklen_t addr_size;int str_len, state;char buf[BUF_SIZE];if (argc != 2) {printf("Usgae : %s <port>\n", argcv[0]);exit(1);}act.sa_handler = read_childproc;sigemptyset(&act.sa_mask);act.sa_flags = 0;state = sigaction(SIGCHLD, &act, 0);server_sock = socket(PF_INET, SOCK_STREAM, 0);memset(&server_addr, 0, sizeof(server_addr));server_addr.sin_family = AF_INET;server_addr.sin_addr.s_addr = htonl(INADDR_ANY);server_addr.sin_port = htons(atoi(argcv[1]));if (bind(server_sock, (struct sockaddr*)&server_addr, sizeof(server_addr)) == -1) {error_handling("bind() error");}if (listen(server_sock, 5) == -1) {error_handling("listen() error");}pipe(fds);pid = fork();if (pid == 0) { // 负责保存数据到文件的子进程FILE *fp = fopen("echomsg.txt", "wt");char msgbuf[BUF_SIZE];int len;for (int i = 0; i < 10; ++i) {len = read(fds[0], msgbuf, BUF_SIZE);fwrite((void*)msgbuf, 1, len, fp);}fclose(fp);return 0;}while (1) {addr_size = sizeof(client_addr);client_sock =accept(server_sock, (struct sockaddr*)&server_addr, &addr_size);if (client_sock == -1) {continue;} else {puts("new client connected...");}pid = fork();if (pid == 0) {close(server_sock);while ((str_len = read(client_sock, buf, BUF_SIZE)) != 0) {write(client_sock, buf, str_len);write(fds[1], buf, str_len); // 发送数据给负责保存文件的子进程}close(client_sock);puts("client disconnected...");return 0;} else {close(client_sock);}}close(server_sock);return 0;
}

项目代码

github

参考

《TCP/IP网络编程》