How can I get a file's size in C++? [duplicate

Question

This question already has an answer here:

• tellg() function give wrong size of file? 3 answers

Let's create a complementary question to this one. What is the most common way to get the file size in C++? Before answering, make sure it is portable (may be executed on Unix, Mac and Windows), reliable, easy to understand and without library dependencies (no boost or qt, but for instance glib is ok since it is portable library).

Answer 1

It is also possible to find that out using the fopen(),fseek() and ftell() function.

int get_file_size(std::string filename) // path to file
{
    FILE *p_file = NULL;
    p_file = fopen(filename.c_str(),"rb");
    fseek(p_file,0,SEEK_END);
    int size = ftell(p_file);
    fclose(p_file);
    return size;
}