```python
Object representing a file entry in a DDUF file.

See [`read_dduf_file`] for how to read a DDUF file.

Attributes:
filename (str):
The name of the file in the DDUF archive.
offset (int):
The offset of the file in the DDUF archive.
length (int):
The length of the file in the DDUF archive.
dduf_path (str):
The path to the DDUF archive (for internal use).
```