int fd() const { return m_fd; };
/* low level operations */
- virtual int d_ioctl(int fd, ioctl_req_t request, char *mt_com);
+ virtual int d_ioctl(int fd, ioctl_req_t request, char *mt_com=NULL);
virtual int d_open(const char *pathname, int flags);
virtual int d_close(int fd);
virtual ssize_t d_read(int fd, void *buffer, size_t count);