typedef unsigned int u_int; 
typedef u_int SOCKET; 

typedef unsigned char u_char; 
typedef unsigned short u_short; 
typedef unsigned int u_int; 
typedef unsigned long u_long; 

struct in_addr { 
union { 
struct { u_char s_b1,s_b2,s_b3,s_b4; } S_un_b; 
struct { u_short s_w1,s_w2; } S_un_w; 
u_long S_addr; 
} S_un; 
#define s_addr S_un.S_addr /* can be used for most tcp & ip code */ 
//下面幾行省略,反正沒什么用處。 
}; 

struct sockaddr { 
u_short sa_family; /* address family */ 
char sa_data[14]; /* up to 14 bytes of direct address */ 
}; 

struct sockaddr_in { 
short sin_family; 
u_short sin_port; 
struct in_addr sin_addr; 
char sin_zero[8]; 
}; 

unsigned long inet_addr(const char FAR * cp ) 

unsigned long addr=inet_addr("192.1.8.84") 

#define INADDR_ANY (u_long)0x00000000 

struct hostent { 
char FAR * h_name; /* official name of host */ 
char FAR * FAR * h_aliases; /* alias list */ 
short h_addrtype; /* host address type */ 
short h_length; /* length of address */ 
char FAR * FAR * h_addr_list; /* list of addresses */ 
#define h_addr h_addr_list[0] /* address, for backward compat */ 
}; 

#define IPPROTO_IP 0 
#define IPPROTO_ICMP 1 
#define IPPROTO_IGMP 2 
#define IPPROTO_TCP 6 
#define IPPROTO_UDP 17 
#define IPPROTO_RAW 255 

//允許調試輸出 
#define SO_DEBUG 0x0001 /* turn on debugging info recording */ 
//是否監(jiān)聽模式 
#define SO_ACCEPTCONN 0x0002 /* socket has had listen() */ 
//套接字與其他套接字的地址綁定 
#define SO_REUSEADDR 0x0004 /* allow local address reuse */ 
//保持連接 
#define SO_KEEPALIVE 0x0008 /* keep connections alive */ 
//不要路由出去 
#define SO_DONTROUTE 0x0010 /* just use interface addresses */ 
//設置為廣播 
#define SO_BROADCAST 0x0020 /* permit sending of broadcast msgs */ 
//使用環(huán)回不通過硬件 
#define SO_USELOOPBACK 0x0040 /* bypass hardware when possible */ 
//當前拖延值 
#define SO_LINGER 0x0080 /* linger on close if data present */ 
//是否加入帶外數(shù)據(jù) 
#define SO_OOBINLINE 0x0100 /* leave received OOB data in line */ 
//禁用LINGER選項 
#define SO_DONTLINGER (int)(~SO_LINGER) 
//發(fā)送緩沖區(qū)長度 
#define SO_SNDBUF 0x1001 /* send buffer size */ 
//接收緩沖區(qū)長度 
#define SO_RCVBUF 0x1002 /* receive buffer size */ 
//發(fā)送超時時間 
#define SO_SNDTIMEO 0x1005 /* send timeout */ 
//接收超時時間 
#define SO_RCVTIMEO 0x1006 /* receive timeout */ 
//錯誤狀態(tài) 
#define SO_ERROR 0x1007 /* get error status and clear */ 
//套接字類型 
#define SO_TYPE 0x1008 /* get socket type */ 

int getsockopt(SOCKET s, int level, int optname, char FAR * optval, int FAR * optlen) 

int ttl=0; //讀取TTL值 
int rc = getsockopt( s, IPPROTO_IP, IP_TTL, (char *)&ttl, sizeof(ttl)); 
//來自MS platform SDK 2003 

int setsockopt(SOCKET s,int level, int optname,const char FAR * optval, int optlen) 

int ttl=32; //設置TTL值 
int rc = setsockopt( s, IPPROTO_IP, IP_TTL, (char *)&ttl, sizeof(ttl)); 

int WSAStartup( WORD wVersionRequested, LPWSADATA lpWSAData ) 

wVersionRequested=MAKEWORD(2,0) 

typedef struct WSAData { 
WORD wVersion; 
WORD wHighVersion; 
char szDescription[WSADESCRIPTION_LEN+1]; 
char szSystemStatus[WSASYS_STATUS_LEN+1]; 
unsigned short iMaxSockets; 
unsigned short iMaxUdpDg; 
char FAR * lpVendorInfo; 
} WSADATA, FAR * LPWSADATA; 

WORD wVersion=MAKEWORD(2,0); 
WSADATA wsData; 
int nResult= WSAStartup(wVersion,&wsData); 
if(nResult !=0) 
{ 
//錯誤處理 
} 

SOCKET socket( int af, int type, int protocol ); 

SOCKET sock=socket(AF_INET,SOCK_STREAM,IPPROTO_IP); 
if(sock==INVALID_SOCKET) 
{ 
//錯誤處理 
} 

int bind( SOCKET s, const struct sockaddr FAR * name, int namelen ) 

sockaddr_in addr; 
addr. sin_family=AF_INET; 
addr. sin_port= htons(0); //保證字節(jié)順序 
addr. sin_addr.s_addr= inet_addr("192.1.8.84") 
int nResult=bind(s,(sockaddr*)&addr,sizeof(sockaddr)); 
if(nResult==SOCKET_ERROR) 
{ 
//錯誤處理 
} 

int listen(SOCKET s, int backlog ) 

int nResult=listen(s,5) //最多5個連接 
if(nResult==SOCKET_ERROR) 
{ 
//錯誤處理 
} 

SOCKET accept( SOCKET s, struct sockaddr FAR * addr, int FAR * addrlen ) 

sockaddr_in addr; 
SOCKET s_d=accept(s,(sockaddr*)&addr,sizeof(sockaddr)); 
if(s==INVALID_SOCKET) 
{ 
//錯誤處理 
}