study notes for fstream (2)

#include 
#include 
using namespace std;

int copy (const char* A, const char* B){
 ifstream fin (A, ios::in | ios::binary);
 ofstream fout (B, ios::out | ios:: binary);
 if (!fin.is_open() || !fout.is_open()){
  return -1;
 }

 char buf [512];
 while (!fin.eof() && !fin.fail() && !fout.fail()){
  fin.read(buf, 512);
  int n = fin.gcount();
  if ( n > 0 ){
   fout.write(buf, n);
  }
 }

 return fin.eof() ? 0 : -1;
}

int main(){

 int ret = copy ("E:\\sxz\\1.docx" , "E:\\sxz\\B.docx");
 cout << "ret=" << ret << endl;
 return 0;
}