C++文件操作

下例使用这些函数来获得一个二进制文件的大小：
// obtaining file size
#include <iostream.h>
#include <fstream.h>
const char * filename = "example.txt";
int main () {
long l,m;
ifstream file (filename,ios::in|ios::binary);
l = file.tellg();
file.seekg (0, ios::end);
m = file.tellg();
file.close();
cout << "size of " << filename;
cout << " is " << (m-l) << "
bytes.\n";
return 0;
}

--------------------------------------------------