The Windows Sockets socket function creates a socket that is bound to a specific service provider.
SOCKET socket( int af, int type, int protocol );The following are the only two type specifications supported for Windows Sockets 1.1:
TypeExplanationSOCK_STREAMProvides sequenced, reliable, two-way, connection-based byte streams with an OOB data transmission mechanism. Uses TCP for the Internet address family.SOCK_DGRAMSupports datagrams, which are connectionless, unreliable buffers of a fixed (typically small) maximum length. Uses UDP for the Internet address family.In Windows Sockets 2, many new socket types will be introduced and no longer need to be specified, since an application can dynamically discover the attributes of each available transport protocol through the WSAEnumProtocols function. Socket type definitions appear in Winsock2.h, which will be periodically updated as new socket types, address families, and protocols are defined.
protocol [in] Protocol to be used with the socket that is specific to the indicated address family. 该函数创建一个套接字,參数af为协议族类型AF_INET为TCP/IP协议族 type为套接字类型，有两种类似SOCK_STREAM为使用TCP进行通信 SOCK_STREAM为使用UDP进行通信 protocol能够为IPPROTO_TCP或IPPROTO_IP，此參数英语type保存一致 举例:SOCKET S; S=socket(AF_INET,SOCK_STREAM,IPPOTO_TCP)表示使用TCP协议进行通信 2.bind 顾名思义即绑定,用过套接字编程的都知道,当我们编写服务端程序的时候须要使用该函数 MSDN这样描写叙述:The Windows Sockets bind function associates a local address with a socket.
int bind( SOCKET s, const struct sockaddr FAR *name, int namelen );If no error occurs, bind returns zero. Otherwise, it returns SOCKET_ERROR, and a specific error code can be retrieved by calling WSAGetLastError.
该函数将一个本地的地址绑定到一个套接字上，假设绑定不错位，将返回0，否则将返回SOCKET_ERROR 參数s为须要绑定的套接字 參数*name为一个常量sockaddr结构。可是普通情况下我们都使用sockaddr_in结构 其结构定义例如以下: struct sockaddr_in { short int sin_family; /* Address family */ unsigned short int sin_port; /* Port number */ struct sin_addr sin_addr; /* Internet address */ unsigned char sin_zero[8]; /* Same size as struct sockaddr */ }; sin_family：指代协议族，在socket编程中仅仅能是AF_INET sin_port：存储端口号（使用网络字节顺序） sin_addr：存储IP地址。使用in_addr这个数据结构 sin_zero：是为了让sockaddr与sockaddr_in两个数据结构保持大小同样而保留的空字节。 当中sin_addr定义 typedef struct in_addr { union { struct{ unsigned char s_b1,s_b2, s_b3,s_b4;} S_un_b; struct{ unsigned short s_w1, s_w2;} S_un_w; unsigned long S_addr; } S_un; } IN_ADDR; 一般我们这样用 addrs.sin_addr.S_addr=inet_addr("192.168.1.110") 函数inet_addr能够把字符串直接转换成in_addr类型 也能够使用inet_ntoa()将in_addr类型转换为字符串类型 參数namelen即为name的长度 即sizeof(name) 举个典型的样例: SOCKET s; s=socket(AF_INET,SOCK_STREAM,IPPOTO_TCP); sockaddr_in addrbindto; addrbindto.sin_family=AF_INET; addrbindto.port=htons(8001) htons是将u_short类型转换为网络字节序,htonl是将u_long类型转换为网络字节序 addrbindto.sin_addr_S_addr=inet_addr("192.168.1.110") bind(s,( const struct sockaddr )&addrbindto,sizeof(addrbindto)) 3.listenThe Windows Sockets listen function places a socket a state where it is listening for an incoming connection.
int listen( SOCKET s, int backlog );If no error occurs, listen returns zero. Otherwise, a value of SOCKET_ERROR is returned, and a specific error code can be retrieved by calling WSAGetLastError.
该函数在指定的套接字上监听连接请求,參数s为监听的套接字,backlog表示表示同意的最大连接数 举例: listen(s,5); 4.connectThe Windows Sockets connect function establishes a connection to a specified socket.
int connect( SOCKET s, const struct sockaddr FAR *name, int namelen );The Windows Sockets send function sends data on a connected socket.
int send( SOCKET s, const char FAR *buf, int len, int flags );The Windows Sockets recv function receives data from a connected socket.
int recv( SOCKET s, char FAR *buf, int len, int flags );转载于:https://www.cnblogs.com/bhlsheji/p/5404355.html
