NO This is what RAII is for, let the destructor do its job. There is no harm in closing it manually, but it’s not the C++ way, it’s programming in C with classes. If you want to close the file before the end of a function you can always use a nested scope. In the … Read more
-1 is get‘s way of saying you’ve reached the end of file. Compare it using the std::char_traits<char>::eof() (or std::istream::traits_type::eof()) – avoid -1, it’s a magic number. (Although the other one is a bit verbose – you can always just call istream::eof) The EOF flag is only set once a read tries to read past the … Read more
tellg does not report the size of the file, nor the offset from the beginning in bytes. It reports a token value which can later be used to seek to the same place, and nothing more. (It’s not even guaranteed that you can convert the type to an integral type.) At least according to the … Read more
As Neil pointed out, “the C++ runtime should deal correctly with whatever the line ending convention is for your particular platform.” However, people do move text files between different platforms, so that is not good enough. Here is a function that handles all three line endings (“\r”, “\n” and “\r\n”): std::istream& safeGetline(std::istream& is, std::string& t) … Read more
Updates: Be sure to check the (surprising) updates below the initial answer Memory mapped files have served me well1: #include <boost/iostreams/device/mapped_file.hpp> // for mmap #include <algorithm> // for std::find #include <iostream> // for std::cout #include <cstring> int main() { boost::iostreams::mapped_file mmap(“input.txt”, boost::iostreams::mapped_file::readonly); auto f = mmap.const_data(); auto l = f + mmap.size(); uintmax_t m_numLines = … Read more
After taking a closer look at reading text files in C++, I settled on this passable but most likely far from ideal solution: #include <iostream> #include <fstream> #include <string> using namespace std; int main() { string TextFile; cout << “Enter the wordlist to search:” << “\n”; getline(cin, TextFile); string Search; int Offset = 0; int … Read more