简化服务器端Socket创建的函数

#include
#include
#include
#include
#include
using namespace std;

SOCKET sockserver(char const* service,char const* transport,int qlen)
{
 struct sockaddr_in ipaddr; //主机IP地址
 struct servent * servinfo; //服务器信息
 struct protoent* protoinfo; //传输类型信息
 int sock,type; //套接字描述符

 memset(&ipaddr, 0, sizeof(ipaddr));
 ipaddr.sin_family = AF_INET;
 ipaddr.sin_addr.s_addr = INADDR_ANY;

 //从服务名得到服务端口
 if(servinfo=getservbyname(service,transport))
  ipaddr.sin_port = htons(ntohs((u_short)servinfo->s_port));
 else if((ipaddr.sin_port=htons((u_short)atoi(service)))==0){
  cout<< "Get portnumber error \n" <  WSACleanup();
  exit(1);
 }

 //从传输协议名得到对应编号
 if((protoinfo = getprotobyname(transport)) == 0){
  cout << "get proto naumber error" << endl;
  WSACleanup();
  exit(1);
 }

 //根据传输协议给对应变量赋值
 if(strcmp(transport,"udp") == 0){
  type = SOCK_DGRAM;
 }else{
  type = SOCK_STREAM;
 }

 //创建套接字
 sock = socket(AF_INET,type,protoinfo->p_proto);
 if(sock == INVALID_SOCKET){
  cout << "create socket error" << endl;
  WSACleanup();
  exit(1);
 }

 //绑定本地IP地址
 if(bind(sock,(sockaddr *)&ipaddr,sizeof(ipaddr))==SOCKET_ERROR){
  cout << "socket bind error" << endl;
  WSACleanup();
  exit(1);
 }

 //如果是流式套接字，则使套接字处于监听状态
 if(type == SOCK_STREAM){
  if(listen(sock,qlen)==SOCKET_ERROR){
   cout << "socket listen error" << endl;
   WSACleanup();
   exit(1);
  }
 }
 return sock;
}

SOCKET UDPServer(char const * service){
 return sockserver(service,"udp",0);
}

SOCKET TCPServer(char const * service,int qlen){
 return sockserver(service,"tcp",qlen);
}

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