C / C++ / MFC

char* load_string(FILE* f)
{
    size_t len;
    char* str = NULL;
    fread(&len, sizeof(size_t), 1, f); /* this correctly returns # of bytes */
    if (len)
    {
        /* if not null */
        str=(char*)malloc(len);
        fread(str, sizeof(char), len, f);
    }
    else
    {
        /* null pointer */
        str=NULL;
    }
    return str;
}

fopen_s(&f, "hi.dat", "rb"); /* open for reading */
if (f)
{
    szLoad = load_string(f);
    fclose(f);
}