Fastest way to check if a file exist using standard C++/C++11/C?

Question

I would like to find the fastest way to check if a file exist in standard C++11, C++, or C. I have thousands of files and before doing something on them I need to check if all of them exist. What can I write instead of `/* SOMETHING */` in the following function? inline bool exist(const std::string& name) { /* SOMETHING */ }

Answer 1

For C++, it depends on the standard version. For C++11, you can use the std::ifstream like:

std::fstream file(fileName);

return file.good();

For C++17 and higher, and especially if you have to deal with many files, you can use the std::filesystem::exists method:

return std::filesystem::exists(fileName);

Hope this helps!

Brandon