Echo实验

#include <stdio.h>
#include <time.h>
#include <winsock2.h>
#include <conio.h>
#define BUFLEN 2000
#define WSVERS MAKEWORD(2, 0)
#pragma comment(lib, "ws2_32.lib") //使用winsock 2.2 library
int main(int argc, char *argv[])   // argc: 命令行参数个数，例如：C:\> TCPServer 8080 argc=2 argv[0]=「TCPServer", argv[1]="8080"
{
	struct sockaddr_in fsin; // the from address of a client
	SOCKET msock, ssock;	 // master & slave sockets
	WSADATA wsadata;
	char service[] = "50500";
	struct sockaddr_in sin;							   // an Internet endpoint address
	int alen;										   // from-address length
	char pts[BUFLEN + 1];							   // pointer to time string
	time_t now;										   // current time
	WSAStartup(WSVERS, &wsadata);					   // 加载winsock library，WSVERS为请求版本，wsadata返回系统实际支持的最高版本
	msock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP); // 创建套接字。 参数：因特网协议簇(family)，字节流，TCP协议号。 返回：要监听套接字的描述符或INVALID_SOCKET
	memset(&sin, 0, sizeof(sin));					   //从&sin开始的长度为sizeof(sin)的内存清0 , sin为一个地址结构
	sin.sin_family = AF_INET;						   //因特网地址簇(INET-Internet)
	sin.sin_addr.s_addr = INADDR_ANY;				   //监听所有(接口的)IP地址(32位)，// 0.0.0.0
	sin.sin_port = htons((u_short)atoi(service));	  //监听的端口号(16位) 。atoi--把ascii转化为int，htons—主机序到网络序
	bind(msock, (struct sockaddr *)&sin, sizeof(sin)); // 通过sin把要监听的IP地址和端口号绑定到套接字上
	listen(msock, 5);								   // 建立长度为5的连接请求队列，并开始监听是否有连接请求到来，来了则放入队列
	printf("Server Start to listen.\n");
	while (!_kbhit()) // 检测是否有按键 (什么时候执行？)
	{
		alen = sizeof(struct sockaddr);
		ssock = accept(msock, (struct sockaddr *)&fsin, &alen); // accept：如果有新的连接请求，返回连接套接字，否则，被阻塞，fsin包含客户端IP地址和端口号
		time(&now);												// 取得系统时间
		int cnt = sprintf(pts, "Accept Time:\n"
							   "%s"
							   "sin_port:\n"
							   "%u\n"
							   "sin_addr:\n"
							   "%d.%d.%d.%d\n"
							   "Receive Message:\n",
						  ctime(&now),
						  fsin.sin_port,
						  fsin.sin_addr.S_un.S_un_b.s_b1,
						  fsin.sin_addr.S_un.S_un_b.s_b2,
						  fsin.sin_addr.S_un.S_un_b.s_b3,
						  fsin.sin_addr.S_un.S_un_b.s_b4); // 把时间转换为字符串
		int cc = recv(ssock, pts + cnt, BUFLEN - cnt, 0);
		pts[cnt + cc] = 0;
		printf("\n%s\n", pts);
		send(ssock, pts, cnt + cc, 0);
		closesocket(ssock); //  关闭连接套接字
	}
	closesocket(msock);
	WSACleanup();
	system("pause");
}

#include <stdio.h>
#include <string.h>
#include <winsock2.h>
#define BUFLEN 2000
#define WSVERS MAKEWORD(2, 0)
#pragma comment(lib, "ws2_32.lib")
int main(int argc, char *argv[])
{
	char host[] = "127.0.0.1";			   // server IP to connect，127.0.0.1指本机
	char service[] = "50500";			   // server port to connect
	struct sockaddr_in sin;				   // an Internet endpoint address
	char buf[BUFLEN + 1], msg[BUFLEN + 1]; // buffer for one line of text
	SOCKET sock;						   // socket descriptor
	int cc;								   // recv character count
	WSADATA wsadata;
	WSAStartup(WSVERS, &wsadata);
	sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
	memset(&sin, 0, sizeof(sin));				  // sin的内存清0
	sin.sin_family = AF_INET;					  // 因特网地址簇
	sin.sin_addr.s_addr = inet_addr(host);		  // 服务器IP地址(32位)
	sin.sin_port = htons((u_short)atoi(service)); // 服务器端口号(16位)
	printf("Send the Message:\n");
	gets(msg);
	int ret = connect(sock, (struct sockaddr *)&sin, sizeof(sin)); // 连接到服务器.无错时，返回0， // 否则，返回SOCKET_ERROR ，可以调用 //    函数WSAGetLastError取得错误代码
	cc = send(sock, msg, strlen(msg), 0);						   //把缓冲区pts的数据发送出去，len为要发送的字节数， // 返回值：(>0) 实际发送的字节数(≤len), (=0) 对方正常关闭， //    （=SOCKET_ERROR) 出错，用函数WSAGetLastError取错误码。
	cc = recv(sock, buf, BUFLEN, 0);							   // BUFLEN为缓冲区buf的长度。 // 返回值：接收的字符数(>0)、对方已关闭(=0) 或连接出错(<0)
	if (cc == SOCKET_ERROR)
		printf("Error:\n%d.\n", GetLastError());
	else if (cc == 0)
		printf("Server closed.\n");
	else if (cc > 0)
	{
		buf[cc] = '\0';		   //  ensure null-termination
		printf("\n%s\n", buf); // 显示所接收的字符串
	}
	closesocket(sock); // 关闭套接字
	WSACleanup();	  //  卸载winsock library
	system("pause");
}

#include <stdio.h>
#include <string.h>
#include <time.h>
#include <conio.h>
#include <winsock2.h>
#define BUFLEN 2000				   // 缓冲区大小
#define WSVERS MAKEWORD(2, 2)	  // 指明版本2.2
#pragma comment(lib, "ws2_32.lib") // 加载winsock 2.2 Llibrary
void main(int argc, char *argv[])
{
	char host[] = "127.0.0.1"; // server IP Address to connect
	char service[] = "50500";  // server port to connect
	struct sockaddr_in sin;	// an Internet endpoint address
	struct sockaddr_in from;   // sender address
	int fromsize = sizeof(from);
	char buf[BUFLEN + 1], pts[BUFLEN + 1]; // buffer for one line of text
	SOCKET sock;						   // socket descriptor
	int cc;								   // recv character count
	WSADATA wsadata;
	WSAStartup(WSVERS, &wsadata);					 // 加载winsock library，WSVERS为请求版本,wsadata返回系统实际支持的最高版本。
	sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP); // 创建UDP套接字, 参数：因特网协议簇(family)，数据报套接字，UDP协议号， 返回：要监听套接字的描述符或INVALID_SOCKET
	memset(&sin, 0, sizeof(sin));
	sin.sin_family = AF_INET;
	sin.sin_addr.s_addr = INADDR_ANY;				  // 绑定(监听)所有的接口。
	sin.sin_port = htons((u_short)atoi(service));	 // 绑定指定接口。atoi--把ascii转化为int，htons -- 主机序(host)转化为网络序(network), 为short类型。
	bind(sock, (struct sockaddr *)&sin, sizeof(sin)); // 绑定本地端口号（和本地IP地址)
	printf("UDPServer Start.\n");
	while (!_kbhit())
	{																	   //检测是否有按键
		cc = recvfrom(sock, buf, BUFLEN, 0, (SOCKADDR *)&from, &fromsize); //接收客户数据。返回结果：cc为接收的字符数，from中将包含客户IP地址和端口号。
		if (cc == SOCKET_ERROR)
		{
			printf("recvfrom() failed; %d\n", WSAGetLastError());
			break;
		}
		else if (cc == 0)
			break;
		else
		{
			buf[cc] = 0;
			time_t now;
			time(&now); // 取得系统时间
			sprintf(pts,
					"Accept Time:\n"
					"%s"
					"sin_port:\n"
					"%u\n"
					"sin_addr:\n"
					"%d.%d.%d.%d\n"
					"Receive Message:\n"
					"%s\n",
					ctime(&now),
					from.sin_port,
					from.sin_addr.S_un.S_un_b.s_b1,
					from.sin_addr.S_un.S_un_b.s_b2,
					from.sin_addr.S_un.S_un_b.s_b3,
					from.sin_addr.S_un.S_un_b.s_b4,
					buf);
			printf("%s", pts);
			cc = sendto(sock, pts, strlen(pts), 0, (SOCKADDR *)&from, fromsize);
		}
	}
	closesocket(sock);
	WSACleanup(); // 卸载某版本的DLL
	system("pause");
}

#include <stdio.h>
#include <string.h>
#include <winsock2.h>
#define BUFLEN 2000				   // 缓冲区大小
#define WSVERS MAKEWORD(2, 2)	  // 指明版本2.2
#pragma comment(lib, "ws2_32.lib") // 加载winsock 2.2 Llibrary
void main(int argc, char *argv[])
{
	char host[] = "127.0.0.1";		 // server IP to connect
	char service[] = "50500";		 // server port to connect
	struct sockaddr_in toAddr, from; // an Internet endpoint address
	int fromsize = sizeof(from);
	char buf[BUFLEN + 1]; // buffer for one line of text
	SOCKET sock;		  // socket descriptor
	int cc;				  // recv character count
	WSADATA wsadata;
	WSAStartup(WSVERS, &wsadata); // 启动某版本Socket的DLL
	sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
	memset(&toAddr, 0, sizeof(toAddr));
	toAddr.sin_family = AF_INET;
	toAddr.sin_port = htons((u_short)atoi(service)); //atoi：把ascii转化为int. htons：主机序(host)转化为网络序(network), s--short
	toAddr.sin_addr.s_addr = inet_addr(host);		 //如果host为域名，需要先用函数gethostbyname把域名转化为IP地址
	printf("Send the Message:\n");
	gets(buf);
	cc = sendto(sock, buf, strlen(buf), 0, (SOCKADDR *)&toAddr, sizeof(toAddr));
	if (cc == SOCKET_ERROR)
		printf("Error:\n%d\n", WSAGetLastError());
	else
	{
		cc = recvfrom(sock, buf, BUFLEN, 0, (SOCKADDR *)&from, &fromsize);
		if (cc == SOCKET_ERROR)
			printf("Receive Error:\n%d\n", WSAGetLastError());
		else
			printf("%s", buf);
	}
	closesocket(sock);
	WSACleanup(); // 卸载某版本的DLL
	system("pause");
}