Question

I need a function that simply returns bool if there is an entity at the given path, no matter if file or directory. What function to use either in winapi or stl ?

Answer 1

GetFileAttributes() will return information about a file system object which can be queried to determine if it is a file or directory and it will fail with if it does not exist.

For example:

#include <windows.h>
#include <iostream>

int main(int argc, char* argv[])
{
    if (2 == argc)
    {
        const DWORD attributes = GetFileAttributes(argv[1]);
        if (INVALID_FILE_ATTRIBUTES != attributes)
        {
            std::cout << argv[1] << " exists.\n";
        }
        else if (ERROR_FILE_NOT_FOUND == GetLastError())
        {
            std::cerr << argv[1] << " does not exist\n";
        }
        else
        {
            std::cerr << "Failed to query "
                      << argv[1] 
                      << " : "
                      << GetLastError()
                      << "\n";
        }

    }
    return 0;
}