Seeking in large files with ifstream

Question

I'm implementing a program in C++ using ifstream that must seek in large files (~1TB). However, this fails after reading 2GB. Is there a way to get file positions, even for large files? I compile for a 32-bit windows machine.

std::ifstream f;
f.open( filename.c_str(), std::ifstream::in | std::ifstream::binary );
while(true) {
    std::cout << (uint64_t)(f.tellg()) << std::endl;
    //read data
}

Answer 1

Since you are compiling on a 32-bit platform, if you use fstream, you are going to get 32-bits access. To access large files, you need to use a platform dependent solution :

• for windows, use _lseeki64()
• for linux, use lseek64()