完成了第 11 章 进程间通信

ch11/echo_storeserv.c

@@ -0,0 +1,102 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <signal.h>
+#include <sys/wait.h>
+#include <arpa/inet.h>
+#include <sys/socket.h>
+
+#define BUF_SIZE 30
+void error_handling(char *message);
+void read_childproc(int sig);
+
+int main(int argc, char *argv[])
+{
+    int serv_sock, clnt_sock;
+    struct sockaddr_in serv_adr, clnt_adr;
+    int fds[2];
+
+    pid_t pid;
+    struct sigaction act;
+    socklen_t adr_sz;
+    int str_len, state;
+    char buf[BUF_SIZE];
+    if (argc != 2)
+    {
+        printf("Usgae : %s <port>\n", argv[0]);
+        exit(1);
+    }
+    act.sa_handler = read_childproc; //防止僵尸进程
+    sigemptyset(&act.sa_mask);
+    act.sa_flags = 0;
+    state = sigaction(SIGCHLD, &act, 0);         //注册信号处理器,把成功的返回值给 state
+    serv_sock = socket(PF_INET, SOCK_STREAM, 0); //创建服务端套接字
+    memset(&serv_adr, 0, sizeof(serv_adr));
+    serv_adr.sin_family = AF_INET;
+    serv_adr.sin_addr.s_addr = htonl(INADDR_ANY);
+    serv_adr.sin_port = htons(atoi(argv[1]));
+
+    if (bind(serv_sock, (struct sockaddr *)&serv_adr, sizeof(serv_adr)) == -1) //分配IP地址和端口号
+        error_handling("bind() error");
+    if (listen(serv_sock, 5) == -1) //进入等待连接请求状态
+        error_handling("listen() error");
+
+    pipe(fds);
+    pid = fork();
+    if (pid == 0)
+    {
+        FILE *fp = fopen("echomsg.txt", "wt");
+        char msgbuf[BUF_SIZE];
+        int i, 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)
+    {
+        adr_sz = sizeof(clnt_adr);
+        clnt_sock = accept(serv_sock, (struct sockaddr *)&clnt_adr, &adr_sz);
+        if (clnt_sock == -1)
+            continue;
+        else
+            puts("new client connected...");
+        pid = fork(); //此时，父子进程分别带有一个套接字
+        if (pid == 0) //子进程运行区域,此部分向客户端提供回声服务
+        {
+            close(serv_sock); //关闭服务器套接字，因为从父进程传递到了子进程
+            while ((str_len = read(clnt_sock, buf, BUFSIZ)) != 0)
+            {
+                write(clnt_sock, buf, str_len);
+                write(fds[1], buf, str_len);
+            }
+
+            close(clnt_sock);
+            puts("client disconnected...");
+            return 0;
+        }
+        else
+            close(clnt_sock); //通过 accept 函数创建的套接字文件描述符已经复制给子进程，因为服务器端要销毁自己拥有的
+    }
+    close(serv_sock);
+
+    return 0;
+}
+
+void error_handling(char *message)
+{
+    fputs(message, stderr);
+    fputc('\n', stderr);
+    exit(1);
+}
+void read_childproc(int sig)
+{
+    pid_t pid;
+    int status;
+    pid = waitpid(-1, &status, WNOHANG);
+    printf("removed proc id: %d \n", pid);
+}