停止和启动二进制文件的读取/复制

所以我试图将二进制文件复制到某个点…停止…执行一些操作,然后将剩余内容从原始二进制文件复制到新二进制文件。但是,当我执行第二次读取操作时,我的读取缓冲区是空的。有人能指出我做错了什么吗?非常感谢。。。

ifstream fin;
fin.open(argv[1], ios::in | ios::binary);

ofstream fout("test.bin", ios::out | ios::binary);

int position = getPositionX();
fin.seekg(position);
streamoff initialCopyLength = fin.tellg();
char * readBuffer = new char[initialCopyLength];
fin.seekg(0, fin.beg);
fin.read(readBuffer, initialCopyLength);
fout.write(readBuffer, initialCopyLength);

///perform some operations, then copy out the rest of the binary

int currentPosition = fin.tellg();
fin.seekg(0, fin.end);
streamoff length = fin.tellg();
readBuffer = new char[length];
fin.read(readBuffer, length);
//write out last part of file
fout.write(readBuffer, length);
fin.close();
fout.close();