程序代码：

const std::string GetJustFileName(const char* str)
{
    const char* ptr_start = strrchr(str, '\\');
    if (!ptr_start)
    {
        ptr_start = str;
    }
    else
    {
        ++ptr_start;
    }

    const char* ptr_end = strrchr(str, '.');
    if (!ptr_end)
    {
        ptr_end = strrchr(str, '\0');
    }

    size_t start = ptr_start - str;
    size_t count = ptr_end - ptr_start;
    return std::string(str, start, count);
}