下载文件要用到操作系统的API函数，下面是一个WINDOWS系统中的实现：
//---------------------------------------------------------------------------
#include "stdafx.h"
#include <stdio.h>
#include <windows.h>
#include <wininet.h>
#define MAXBLOCKSIZE 1024
#pragma comment( lib, "wininet.lib" ) ;
void download(const char *Url,const char *save_as)/*将Url指向的地址的文件下载到save_as指向的本地文件*/
{
byte Temp[MAXBLOCKSIZE];
ULONG Number = 1;
FILE *stream;
HINTERNET hSession = InternetOpen(_T("RookIE/1.0"), INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
if (hSession != NULL)
{
HINTERNET handle2 = InternetOpenUrl(hSession,_T(Url), NULL, 0, INTERNET_FLAG_DONT_CACHE, 0);
if (handle2 != NULL)
{
if( (stream = fopen( save_as, "wb" )) != NULL )
{
while (Number > 0)
{
InternetReadFile(handle2, Temp, MAXBLOCKSIZE - 1, &Number);
fwrite(Temp, sizeof (char), Number , stream);
}
fclose( stream );
}
InternetCloseHandle(handle2);
handle2 = NULL;
}
InternetCloseHandle(hSession);
hSession = NULL;
}
}
int main(int argc, char* argv[]){
download("http://www.xmgpt.org/luke/the%20sound%20of%20science.mp3","c:\\index.html");/*调用示例，下载百度的首页到c:\index.html文件*/
return 0;
}