Function unbounded_seek 

pub fn unbounded_seek(
    current_offset: off_t,
    target: SeekTarget,
) -> Result<off_t, Errno>

Implement the seek method for a file without an upper bound on the resulting offset.

This is useful for files without a defined size.

Errors if the calculated offset is invalid.

• current_offset: The current position
• target: The location to seek to.