void receiveFile(int sock, char* filename)
{
	FILE * pFile;
	pFile = fopen(filename, "wb");

	message msg;
	void* buffer = (void*) &msg;
	int rBytes, rv;
	int pause;
	
	int finished = 0;
	int bytesWritten = 0;
	
	while(!finished)
	{
		//ensure that we receive a complete msg object from the other end
		for(rBytes = 0; rBytes < sizeof(msg); rBytes += rv)
		{
			if((rv = recv(sock, buffer+rBytes, sizeof(msg)-rBytes, 0)) < 0)
				dieWithError("recv() failed");
		}
		
		//convert size from network to host byte order
		msg.size = ntohl(msg.size);
		
		//write the data we just received to the file
		if(msg.size - bytesWritten < sizeof(msg.data))
		{
			fwrite(msg.data,1,msg.size - bytesWritten,pFile);
			finished = 1;
		}
		else
		{
			fwrite(msg.data, 1, sizeof(msg.data), pFile);
			bytesWritten += sizeof(msg.data);
		} 
	}
	//close file
	fclose (pFile);
}

void sendFile(int sock, char* filename)
{
	FILE* pFile;
	long fileSize;
	char* buffer;
	size_t result;
	
	int copied;

	pFile = fopen(filename,"rb");
	if(pFile==NULL)
		printf("error with fopen()");
		
	// obtain file size:
	fseek(pFile, 0, SEEK_END);
	fileSize = ftell(pFile);
	fseek(pFile, 0, SEEK_SET);

	// allocate memory to contain the whole file:
	buffer = (char*)malloc(sizeof(char) * fileSize);
	if(buffer == NULL)
		printf("error with malloc()");

	// copy the file into the buffer:
	result = fread(buffer, 1, fileSize,pFile);
	if(result != fileSize)
		printf("error with fread()");

	//the whole file is now loaded in the memory buffer.
	
	//send file to other client
	message msg;
	
	copied = 0;
	while(copied < fileSize)
	{
		memset(&msg, 0, sizeof(msg));
		if(fileSize - copied < sizeof(msg.data))
		{
			memcpy(msg.data, buffer + copied, fileSize - copied);
			copied += fileSize - copied;
		}
		else
		{
			memcpy(msg.data, buffer + copied, sizeof(msg.data));
			copied += sizeof(msg.data);
		} 
		msg.size = htonl(fileSize);
		send(sock, &msg, sizeof(msg), 0);
	}

	//close file
	fclose(pFile);
	free(buffer);
}

void sendFile(int sock, char* filename)
{
	FILE* pFile;
	long fileSize;
	char* buffer;
	size_t readIn;
	
	int copied;

	pFile = fopen(filename,"rb");
	if(pFile==NULL)
		printf("error with fopen()");
		
	// obtain file size:
	fseek(pFile, 0, SEEK_END);
	fileSize = ftell(pFile);
	fseek(pFile, 0, SEEK_SET);
	
	//send file to other client
	message msg;
	copied = 0;
	
	while(copied < fileSize)
	{
		//allocate a buffer of appropriate size
		if(fileSize - copied < sizeof(msg.data))
			buffer = (char*)malloc((fileSize - copied) * sizeof(char));
		else
			buffer = (char*)malloc(sizeof(msg.data) * sizeof(char));
		
		//read in some data from the file
		readIn = fread(buffer, 1, sizeof(buffer), pFile);
		if(readIn != sizeof(buffer))
			printf("error with fread()");
		
		//transfer the data into our message struct
		memset(&msg, 0, sizeof(msg));
		memcpy(msg.data, buffer, sizeof(buffer));
		copied += sizeof(buffer);

		msg.size = htonl(fileSize);
		send(sock, &msg, sizeof(msg), 0);
		free(buffer);
	}

	//close file
	fclose(pFile);
}