请问linux如果通过TCP传输多张图片

[ZJE_ANDY]

我传输一张图片是可以的，但如果连续传两张，那么第二张就会打不开，而且第二张为0KB
这是客户端发送的代码：

fseek(fp,0,SEEK_END);
	file_len = ftell(fp);
	fseek(fp,0,SEEK_SET);

	tcp_num = file_len/BUFFMAX;
	printf("tcpnum=%d\n",tcp_num);
	if((tcp_num*BUFFMAX)<file_len)
	{
		tcp_num+=1;
	}

	int i,write_len;
	for(i=0;i<tcp_num;i++)
	{
		if(file_len - i*BUFFMAX >= BUFFMAX)
		{
			file_send_len = BUFFMAX;
		}
		else
		{
			file_send_len = file_len - i*BUFFMAX;
		}
		bzero(buff,BUFFMAX);
		write_len = fread(buff,sizeof(unsigned char),file_send_len,fp);
		len = send(sockfd,buff,file_send_len,0);
		if(len<0)
		{
			perror("failed to send");
			break;
		}
	}
	fclose(fp);

	bzero(buff,BUFFMAX);
	printf("==================传输第二张================\n");
	if(!(fp=fopen("2.jpg","rb+")))
	{
		return -1;
	}

	fseek(fp,0,SEEK_END);
	file_len = ftell(fp);
	fseek(fp,0,SEEK_SET);

	tcp_num = file_len/BUFFMAX;
	printf("tcpnum=%d\n",tcp_num);
	if((tcp_num*BUFFMAX)<file_len)
	{
		tcp_num+=1;
	}

	for(i=0;i<tcp_num;i++)
	{
		if(file_len - i*BUFFMAX >= BUFFMAX)
		{
			file_send_len = BUFFMAX;
		}
		else
		{
			file_send_len = file_len - i*BUFFMAX;
		}
		bzero(buff,BUFFMAX);
		write_len = fread(buff,sizeof(unsigned char),file_send_len,fp);
		len = send(sockfd,buff,file_send_len,0);
		if(len<0)
		{
			perror("failed to send");
			break;
		}
	}
	fclose(fp);

这是服务端：

FILE *fp;
	if((fp = fopen("1.jpg","wb"))==NULL)
	{
		printf("file open err\n");
		return -1;

	}



	while((data_len = recv(new_sockfd,buff,BUFFMAX,0))>0)
	{
		int write_len = fwrite(buff,sizeof(char),data_len,fp);
		printf("write_len = %d\n",write_len);
	}
	fclose(fp);


	if((fp = fopen("2.jpg","wb"))==NULL)
	{
		printf("file open err\n");
		return -1;

	}

	while((data_len = recv(new_sockfd,buff,BUFFMAX,0))>0)
	{
		int write_len = fwrite(buff,sizeof(char),data_len,fp);
		printf("write_len = %d\n",write_len);
	}
	fclose(fp);


	return 0;

其中tcp的连接已经写了，没贴出来而已。
问题是为什么传第一张图片可以，传第二张就不行了

[ZJE_ANDY]

刚刚试了下，问题是因为第二次传图片时recv的返回值=0了，为什么会这样啊？

[小竹z]

楼主先了解下tcp粘包问题吧，再看看recv阻塞模式是什么意思

[风在天边]

我猜测如果你先传2，后传1；会收不到1的；程序逻辑有问题。

[我用双手-成就你的梦想]

datalen = 0;
while(datalen <  filesize)
    {
        int recv_len=  recv(new_sockfd,buff,BUFFMAX,0);
        datalen += recv_len;
        fwrite(buff,sizeof(char),recv_len,fp);
    }
//写成类似这种，我随便写得代码，可能有BUG