socket文件传输功能的实现

#include <stdio.h>
#include <winsock2.h>
#pragma comment (lib, "ws2_32.lib")  //加载 ws2_32.dll

#define BUF_SIZE 1024

int main(int argc, char *argv[]){
//先检查文件是否存在
char *filename = "Beyond.mp3";//文件名
FILE *fp = fopen(filename, "rb");//以二进制方式打开文件
if(fp == NULL)
{
printf("Cannot open file, press any key to exit!\n");
system("pause");
exit(0);
}

//初始化 DLL
WSADATA wsaData;
WSAStartup( MAKEWORD(2, 2), &wsaData);

//创建套接字
SOCKET servSock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if(servSock == INVALID_SOCKET)
{
printf("Failed socket().\n");
WSACleanup();
return 0;
}

//绑定套接字
struct sockaddr_in sockAddr;
memset(&sockAddr, 0, sizeof(sockAddr));  //每个字节都用0填充
sockAddr.sin_family = PF_INET;  //使用IPv4地址
sockAddr.sin_addr.s_addr = inet_addr("127.0.0.1");  //具体的IP地址
sockAddr.sin_port = htons(1234);  //端口
if(bind(servSock, (SOCKADDR*)&sockAddr, sizeof(SOCKADDR)) == SOCKET_ERROR)
{
printf("Failed bind().\n");
WSACleanup();
return 0;
}

//进入监听状态
listen(servSock, 20);

//循环接收客户端请求
int nSize = sizeof(SOCKADDR);
char buffer[BUF_SIZE] = {0};//缓冲区
SOCKADDR clntAddr;
SOCKET clntSock;

for(;;)
{
clntSock = accept(servSock, (SOCKADDR*)&clntAddr, &nSize);
if(clntSock == INVALID_SOCKET)
{
printf("Failed accept().\n");
continue;
}

int nCount;
while(nCount = fread(buffer, 1, BUF_SIZE, fp) > 0)
{
send(clntSock, buffer, nCount, 0);//循环发送数据，直到文件结尾
}
shutdown(clntSock, SD_SEND);//文件读取完毕，断开输出流，向客户端发送FIN包

recv(clntSock, buffer, BUF_SIZE, 0);//阻塞，等待客户端接收完毕

memset(buffer, 0, BUF_SIZE);//设置缓冲区

fclose(fp);
closesocket(clntSock);
}

//关闭套接字
closesocket(servSock);

//终止 DLL 的使用
WSACleanup();

system("pause");
return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <winsock2.h>
#pragma comment(lib, "ws2_32.lib")

#define BUF_SIZE 1024

int main(int argc, char *agrv[])
{
//先输入文件名，看文件是否能创建成功
char filename[100] = {0}; //文件名
printf("Input filename to save: ");
gets(filename);
FILE *fp = fopen(filename, "wb");//以二进制方式打开（创建）文件
if(fp == NULL)
{
printf("Cannot open file, press any key to exit!\n");
system("pause");
exit(0);
}

//初始化DLL
WSADATA wsaData;
WSAStartup(MAKEWORD(2,2), &wsaData);

//创建套接字
SOCKET sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if(sock == INVALID_SOCKET)
{
printf("Failed socket().\n");
WSACleanup();
return 0;
}

//向服务器发起请求
struct sockaddr_in sockAddr;
memset(&sockAddr, 0, sizeof(sockAddr)); //每个字节都用0填充
sockAddr.sin_family = PF_INET;
sockAddr.sin_addr.s_addr = inet_addr("127.0.0.1");
sockAddr.sin_port = htons(1234);
if(connect(sock, (SOCKADDR*)&sockAddr, sizeof(SOCKADDR)) == -1)
{
printf("Failed connect().\n");
WSACleanup();
return 0;
}

//循环接受数据，知道文件传输完毕
char buffer[BUF_SIZE] = {0}; //文件缓冲区
int nCount;
while((nCount = recv(sock, buffer, BUF_SIZE, 0)) > 0)
{
fwrite(buffer, nCount, 1, fp);
}
puts("File transfer success!\n");

memset(buffer, 0, BUF_SIZE);//重置缓冲区

fclose(fp);
closesocket(sock);

//终止使用DLL
WSACleanup();

system("pause");
return 0;
}