Windows Simple Network socket Programming __ Programming

1. File transfer

File transfer by establishing a server client connection. The client enters a filename, the server searches the element, and after the search succeeds, transmits the data to the client. The client accepts the creation of a file in the current directory.

Hdksjfkl.cpp:Defines the entry point for the console application. #include "stdafx.h" #include <stdio.h> #include <stdlib.h> #include <winsock2.h> #include "iostream
"#define MAXSTRINGSIZE 9000 using namespace std;  
    #pragma comment (lib, "Ws2_32.lib")//Get native IP in_addr gethostname (void) {char host_name[255]; Gets the local host name if (GetHostName (host_name, sizeof (host_name)) = = Socket_error) {cout<< "ERROR%d when get" Ting the local host name.  
        <<wsagetlasterror ();  
        Sleep (3000);  
    Exit (-1);  
    ///From the host name database to get the corresponding "IP" struct hostent *phe = gethostbyname (HOST_NAME); if (phe = = 0) {cout<< "yow!  
        Bad host lookup. ";  
        Sleep (3000);  
    Exit (-1);  
    } struct IN_ADDR addr;  
    memcpy (&AMP;ADDR, phe->h_addr_list[0], sizeof (struct in_addr));   
return addr;  
    //Start server socket StartServer (void) {//create socket socket ServerSocket; if ((Serversocket=socket (AF_INET,SOCK_STREAM,IPPROTO_TCP)) ==invalid_socket) {cout<< "failed to create socket.  
        ";  
        Sleep (3000);  
    Exit (-1);  
    Short port=1986;  
    struct sockaddr_in serveraddress;  
    Initializes the specified memory area memset (&serveraddress,0,sizeof (sockaddr_in));  
    Serveraddress.sin_family=af_inet; Serveraddress.sin_addr. S_un.  
    S_ADDR = htonl (Inaddr_any);  
	
    Serveraddress.sin_port = htons (port); Bind if (Bind (ServerSocket, (sockaddr*) &serveraddress,sizeof (serveraddress)) ==socket_error) {Cout<&lt ;" Socket binding to port failed.  
        Port: "<<port;  
        Sleep (3000);  
    Exit (-1); //Enter listening status if (Listen (serversocket,somaxconn) ==socket_error) {cout<<) listening failed.  
        ";  
        Sleep (3000);  
    Exit (-1);   
    //Get server IP struct in_addr addr = GetHostName ();  
    cout<< "Server" <<inet_ntoa (addr) << ": <<port<<" is listening ... "<<endl; Return ServerSocket;
	//Receive Client connection Socket Receiveconnect (socket &serversocket) {char sendbuffer[80] = {0};
    int bytes; Socket clientsocket;//Socket struct sockaddr_in that is used to communicate with the client clientaddress;//socket address memset (&clientaddress  
	
    , 0,sizeof (clientaddress))//initializes the memory int addrlen = sizeof (clientaddress) that holds the client information;  
        Accept connection if ((Clientsocket=accept (ServerSocket, (sockaddr*) &clientaddress,&addrlen) ==invalid_socket) { cout<< "Accept client connection failed.  
        ";  
        Sleep (3000);  
    Exit (-1);
	} cout<< "Accept connection from" <<inet_ntoa (CLIENTADDRESS.SIN_ADDR) <<endl;  sprintf (Sendbuffer, "welcome\r\n");
    Send welcome message to Client bytes = Send (Clientsocket,sendbuffer,strlen (Sendbuffer), 0);  
return clientsocket;
		} void Sendfile (SOCKET &serversocket) {while (1) {//Accept client command and invoke handler function FILE * fp = NULL;
		Char buf[30];
		Char senmm[10];
		memset (senmm,0,sizeof (SENMM));
		Char sendbuf[500]; memset (sendbuf,1,sizeof) (sendBUF));
		Char maxbuf[500];	
		memset (maxbuf,1,sizeof (MAXBUF));
		Char sendmsg[50];
		memset (sendmsg,0,sizeof (sendmsg));
		SOCKET Clientsocket = Receiveconnect (ServerSocket);
		do {memset (buf,1,sizeof (BUF));
		int bytes = 0;
			if ((bytes = recv (Clientsocket,buf,strlen (BUF) +1,0)) ==socket_error) {sprintf (sendmsg, "Receive data failed");
			Send (Clientsocket,sendmsg,strlen (sendmsg), 0);
		Break
		} if (fp = fopen (buf, "r") = = NULL) {sprintf (senmm, "filename error");
		Send (Clientsocket,senmm,strlen (SENMM) +1,0);
		printf ("The file name from the client is not \ n");
		printf ("%d bytes \ n", bytes);
			else {sprintf (senmm, "250");	
			Send (CLIENTSOCKET,SENMM, strlen (senmm) + 1,0);
			printf ("Client sends file download request, filename is%s\n", buf);
			Break
		Sleep (3000);
		}}while (1);
		Sleep (3000);
		Char mmmm[1000];
		Mmmm[0] = ' the ';
		while (Fgets (MAXBUF,80,FP)!= NULL) {//loop reads the file and sends it through H_newsocket to client printf ("%s\n", maxbuf);
			sprintf (SendBuf, "%s", maxbuf);
			strcat (MMMM,MAXBUF); Send (Clientsocket,maxbuf,strlen (MAXBUF) + 1,0);
		printf (".");
		*/printf ("%s", sendbuf);
		Fclose (FP);
		printf ("%s", MMMM);
		Send (Clientsocket,mmmm,strlen (MMMM) + 1,0);
		sprintf (SENMM, "266");
		Send (Clientsocket,senmm,strlen (SENMM) + 1,0);
	Closesocket (Clientsocket);
	int main (int argc, char* argv[]) {wsadata wsa; if (WSAStartup (Makeword (2,2), &AMP;WSA)!= 0) {printf (socket initialization failed!!)
		\ n ");
		Sleep (3000);
	Exit (-1);
	SOCKET ServerSocket = StartServer ();
	
	Sendfile (ServerSocket);
return 0;
 }

The above is the code for the server segment.

Hdksjfklclien.cpp:Defines the entry point for the console application. #include "stdafx.h" #include <windows.h> #include <process.h> #include <iostream> #include "  
String.h "using namespace std;   
    #pragma comment (lib, "Ws2_32.lib")//Receive data void receive (socket socket) {char buf[2096];  
    int bytes;  
            if ((Bytes=recv (socket,buf,sizeof (BUF), 0)) ==socket_error) {printf ("Failed to receive data!\n");  
        Exit (-1);  
        } buf[bytes]= ';   
cout<<buf<<endl;  
    //Get server IP unsigned long getserverip (void) {//Convert the IP address of the string to U_long char ipstr[20];  
	Fills the memory referred to in the first argument with the second parameter, the size of the third parameter memset (ipstr,0,sizeof (IPSTR));  
	cout<< "Please enter the server IP you want to link:";  
	cin>>ipstr;
    strcpy (Ipstr, "127.0.0.1");  
    unsigned long IP;  
        if ((Ip=inet_addr (IPSTR)) ==inaddr_none) {cout<< "Illegal IP address:";  
        Sleep (3000);  
    Exit (-1);  
} return IP; }  
Send data char path[80] = {' 0 '};
	void Sendmsg (SOCKET &sock) {printf ("Please enter the filename to download \ n");
	scanf ("%s", path);
        printf ("%d\n", strlen (path)); if (Send (Sock,path,strlen (path) +1,0) ==socket_error) {cout<< failed to send data.  
            ";  
        Exit (-1);
cout<< "Send data is" <<path<<endl;  
    }//link server void CConnect (SOCKET &sock) {unsigned long ip=getserverip ();  
    Converts the port number to an integer short port=1986;  
    cout<< "Connecting to" <<inet_ntoa (* (in_addr*) &ip) << ":" <<port<<endl;  
    struct sockaddr_in serveraddress;  
    memset (&serveraddress,0,sizeof (sockaddr_in));  
    Serveraddress.sin_family=af_inet; Serveraddress.sin_addr. S_un.  
    s_addr= IP;  
    Serveraddress.sin_port = htons (port); Establish a connection to the server if (Connect (sock, (sockaddr*) &serveraddress,sizeof (serveraddress)) ==socket_error) {cout<& lt; "   
        Failed to establish connection: "<<wsagetlasterror ();  
        Sleep (3000);Exit (-1);  
    int main (int argc, char* argv[]) {wsadata wsa;  
        Initialize socket DLL if (WSAStartup (Makeword (2,2), &AMP;WSA)!=0) {cout<< "socket initialization failed!";  
        Sleep (3000);  
    Exit (-1);  
    ///create socket socket sock; The If ((Sock=socket (AF_INET,SOCK_STREAM,IPPROTO_TCP)) ==invalid_socket) {cout<< failed to create a socket.  
        ";  
    Exit (-1);
	} cconnect (sock);//Linked server Receive (sock);	
	
	Char buf[10];	
		while (1) {if (strncmp (buf, ",", Strlen ("(") + 1) = 0)) break;
		Sendmsg (sock);
			
	Recv (Sock,buf,strlen (BUF) + 1,0);
	} FILE *FP;
	Char recvbuf[1000];
	memset (recvbuf,1,sizeof (RECVBUF));
		if (fp = fopen (Path, "w+") = = NULL) {printf ("Local open file error \ n");
	return 0;
	}//int bytee = 0;
	 printf ("%s\n", recvbuf);
	 Recv (Sock,recvbuf,sizeof (RECVBUF), 0);
	printf ("%s", recvbuf);

	
	fprintf (FP,RECVBUF);
	Fclose (FP);
	Closesocket (sock);
	WSACleanup ();
	printf ("File received \ n");
return 0;
 }

The above is the client code.