2

server-exp2/togglesp.c

@@ -0,0 +1,82 @@
+#include "common.h"
+
+void sigchld_handler(int sig) 
+{
+    while (waitpid(-1, 0, WNOHANG) > 0);
+    return;
+}
+
+typedef void (*sighandler_t) (int sig) ;
+
+void Signal(int sig, sighandler_t handler){
+    struct sigaction sa;
+    sa.sa_handler = sigchld_handler;
+    sigemptyset(&sa.sa_mask);
+    sa.sa_flags = SA_RESTART;  // 确保被信号中断的系统调用自动重启
+    sigaction(SIGCHLD, &sa, NULL);
+}
+
+void toggle(int conn_sock,int hit) 
+{
+    size_t n; int i,no=0;
+    char buf[MAXLINE]; 
+
+    printf("第%d个客户通信开始\n",hit);
+    while((n =recv(conn_sock, buf, MAXLINE,0))> 0) {
+	printf("toggle服务器收到第%d个客户第%d个消息,长度为%d字节\n", hit,++no,(int)n);
+
+        for(i=0; i<n; i++)
+            if(isupper(buf[i])) 
+                buf[i]=tolower(buf[i]);
+            else if(islower(buf[i]))
+                buf[i]=toupper(buf[i]);
+               
+	send (conn_sock, buf, n, 0);
+    }
+    printf("第%d个客户通信结束\n",hit);
+}
+
+int main(int argc, char **argv) 
+{
+    int listen_sock, conn_sock, port; 
+    struct sockaddr_in clientaddr; 
+    struct hostent *hp;
+    char *haddrp;
+    int hit;
+        
+    socklen_t clientlen=sizeof(struct sockaddr_in);
+
+    if (argc != 2) {
+	    fprintf(stderr, "usage: %s <port>\n", argv[0]);
+	    exit(1);
+    }
+    port = atoi(argv[1]);
+
+    //设置SIGHLD的信号处理函数，用于收割结束的子进程
+    Signal(SIGCHLD, sigchld_handler);
+    
+    listen_sock = open_listen_sock(port);
+    
+    if( listen_sock==-1) {
+    	printf("端口号%d繁忙\n",port);
+    	exit(1);
+    }
+    
+    for(hit=1; ; hit++) {
+	conn_sock = accept(listen_sock, (SA *) &clientaddr, &clientlen);
+
+        /* determine the domain name and IP address of the client */
+	hp = gethostbyaddr((const char *)&clientaddr.sin_addr.s_addr, 
+			   sizeof(clientaddr.sin_addr.s_addr), AF_INET);
+	haddrp = inet_ntoa(clientaddr.sin_addr);
+	printf("server connected to %s (%s)\n", hp->h_name, haddrp);
+
+	if (fork() == 0) { 
+	       close(listen_sock);     /* Child process closes its listening socket */
+	       toggle(conn_sock,hit);    /* Child process services client */
+	       close(conn_sock);     /* Child process closes connection with client */
+	       exit(0);                /* Child process exits */
+	}
+	close(conn_sock);         /* Parent closes connected socket (important!) */
+    }
+}