#include "common.h"

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, clientlen;
    struct sockaddr_in clientaddr;
    struct hostent *hp;
    char *haddrp;
    int hit;
	
    if (argc != 2) {
	    fprintf(stderr, "usage: %s <port>\n", argv[0]);
	    exit(1);
    }
    port = atoi(argv[1]);

    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++) {
	    clientlen = sizeof(clientaddr);
	    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);

	    toggle(conn_sock,hit);
	    close(conn_sock);
    }
    exit(0);
}