server.c

Linux下服务器即时通信程序

#include <arpa/inet.h>
#include<stdlib.h>
#include<unistd.h>
#include<errno.h>
#include<sys/socket.h>
#include<sys/select.h>
#include <sys/types.h>
#include <sys/stat.h>
#include<stdio.h>
#define MAX_LISTEN 10
char *buff2;
//接受客户数据
int recv_data(int sock, char *buf, int len)
{
	int lt=0;
	if((lt=read(sock, buf,len)) < 0){
		perror("recv error");
		return -1;
	  }
	else if(lt == 0){
		printf("client shutdown the socket %d", sock);
		return 0;
	  }
    printf("recv data %s\n", buf);
	return lt;
}
//将数据发到客户指定地点
int send_data(char *buf)
{
	int i=0;
	while((*(buff2+i) = *(buf + i + 1)) != '\0')
		i++;

}	

int
main(void)
{
	int client,ret,i,max_fd;
	char sig;
	char buff[1000]; //客户数据缓存
	char buf2[10]={0,1,2,3,4,5,6,7,8,9};  //10个客户 
	int sock;
	struct sockaddr_in addr;
	int client_fd[MAX_LISTEN];
    
	fd_set readset,writeset;
	if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0)
	{
		perror("socket");
		exit(1);
	}
	addr.sin_family = AF_INET;
	addr.sin_port = htons(2008);
	inet_pton(AF_INET, "192.168.1.57", &addr.sin_addr);
	if (bind(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0){
        perror("bind");
        exit(1);
       }
		listen(sock, MAX_LISTEN);
  
	   
	for(i = 0;i < MAX_LISTEN;i++) 
     client_fd[i]= -1;
	FD_ZERO(&writeset);
    max_fd=sock;
while(1){
    
    FD_ZERO(&readset);
	FD_CLR(sock,&readset);
	FD_CLR(sock,&writeset);
    FD_SET(sock,&readset);
	FD_SET(sock,&writeset);
   if((ret= select(max_fd+1 , &readset , &writeset , NULL , NULL)) < 0)
   {
	   perror("select");
	   exit(-1);
   }
   else if( ret == 0)
   {
  	   printf("select timeout\n");
       continue;
   }
   printf("select\n ");
   
  if( FD_ISSET(sock, &readset)){

	   if( (client = accept(sock, NULL, NULL) < 0))
	   {
		    perror("accept failed");
			continue;
	   }
	   for(i=0;i<MAX_LISTEN;i++)
	   {
		   if(client_fd[i] != -1)
			   continue;
		   client_fd[i] = client;

		   FD_SET(client,&readset);
		    break;
	   }
	   if(max_fd < client)
		   max_fd = client;
	   printf("add client socket connection %d \n", i);
	   continue;
   }
     FD_SET(client, &writeset);
  for(i=0;i < MAX_LISTEN;i++){
	  if( client_fd[i] ==-1)
		  continue;
	  if(!FD_ISSET( client_fd[i],&readset))
		  continue;
     if( (ret = recv_data(client_fd[i], buff, sizeof(buff))) <= 0)      
       {
	    close(client_fd[i]);
		FD_CLR( client_fd[i], &readset);
		printf("del socket %d from select pipe.\n",client_fd[i]);
		client_fd[i] = -1;
		}
     else 
      printf("%s\n",buff);		 
	   send_data(buff);
      sig=*buff;
  if( FD_ISSET(client_fd[sig], &writeset)){
	if ( (ret =send(client_fd[sig], buff2, sizeof(buff2), MSG_EOR)) < 0){
		perror(" send error");
		return -1;
	   }
    else
	printf("send %d data\n", sizeof(buff2));
  }
   }  
    max_fd = sock; 
   for(i = 0; i < MAX_LISTEN;i++){
	if(max_fd < client_fd[i])
	 max_fd = client_fd[i];
   }
  }
return 0;
}