ios::end);//基地址为文件结束处,偏移地址为0,于是指针定位在文件结束处streampos sp=in.tellg();//sp为定位指针,因为它在文件结束处,所以也就是文件的大小cout<<"file size:"<<endl<<sp<<endl;in.seekg(-sp/3,ios::end);//基地址为文件末,偏移地址为负,于是向前移动sp/3个字节stre
open("my.txt", ios::in | ios::out); // getting current location cout << F.tellg() << endl; // seeing 8 bytes/characters F.seekg(8, ios::beg); // now, getting the current location cout << F.tellg() << endl; // extracting one character from current location char c = F....
in.seekg(0, ios::cur); size = in.tellg(); cout << “*** size stream7*** =” << size << endl; in.seekg(-100,ios::end); size = in.tellg(); cout << “*** size stream8*** =” << size << endl; in.seekg(ios::beg,ios::end); size = in.tellg(); cout << “*...
I want to scan for some strings in a file. I open the file using ifstream, read the line with getline and seek the string with string::find. The scan of the first string is ok, However, for the second string I need to position the pointer to the beginning of the file. I use se...
在我的机器上很正常的输出5和1.2
What is the difference between F seek and L seek in C? How do I clear the end of a file in seekg? Using seekg() to set file position in C++ file handling The seekg function is a part of iostream library and enables us to locate any position in a file. Its primary purpose is to...
例:if(in.eof())ShowMessage(“已经到达文件尾!”); 五、C++文件流文件定位 和C的文件操作方式不同的是,C++ I/O系统管理两个与一个文件相联系的指针。一个是读指针,它说明输入操作在文件中的位置;另一个是写指针,它下次写操作的位置。每次执行输入或输出时,相应的指针自动变化。所以,C++的文件定位分为读位...