一个简单的循环式TCP服务器

#include <stdio.h>
#include <stdlib.h>
#include <winsock.h>
#define WSVERS MAKEWORD(2,0)

int passivesock(const char *service, const char *transport, int qlen) ;

int main(int argc, char *argv[])
{
 char s[] = "+OK.THIS IS A TEST SERVCIE";
 char *service = "8273";
 struct sockaddr_in fsin;
 int len;
 WSADATA wsadata;
 SOCKET msock,ssock;

 if(WSAStartup(WSVERS, &wsadata) != 0)
 {
  printf("WSAStartup 初始化失败");
  exit(0);
 }
 msock = passivesock(service,"tcp",5);//5为等待队列长度
 while(1)
 {
  printf("等待连接请求...\n");
  len = sizeof(struct sockaddr);
  ssock = accept(msock, (struct sockaddr *)&fsin, &len);
  if(ssock == -1)
  {
   printf("accept出错");
   exit(0);
  }
    
  if(send(ssock, s, strlen(s) + 1, 0) == SOCKET_ERROR)
  {
  
   printf("send出错");
   exit(0);
  }
  //printf("%s\n",fsin.sin_addr.S_un);
  printf("成功输出\n");
  closesocket(ssock);
 }
 
 return 0;
}

int passivesock(const char *service, const char *transport, int qlen)
{
        struct servent  *pse;
        struct sockaddr_in sin;
        int s, type;       

        memset(&sin, 0, sizeof(sin));
        sin.sin_family = AF_INET;
        sin.sin_addr.s_addr = INADDR_ANY;
        if ( pse = getservbyname(service, transport) )
   sin.sin_port = htons(pse->s_port);
        else if ((sin.sin_port=htons((unsigned short)atoi(service))) == 0)
   exit(0);
       
  if (strcmp(transport, "udp") == 0)               
   type = SOCK_DGRAM;
        else
   type = SOCK_STREAM;
        if(( s = socket(PF_INET, type, 0))<0)
   exit(0);
        if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) < 0)
            exit(0);
        if (type == SOCK_STREAM && listen(s, qlen) < 0)
            exit(0);
        return s;
}