You are aware that `off_t` isn't in the C standard? The standard has `fgetpos`: > The fgetpos function stores the current values of the parse state (if any) a

You are aware that `off_t` isn't in the C standard? The standard has `fgetpos`: > The fgetpos function stores the current values of the parse state (if any) and file position indicator for the stream pointed to by stream in the object pointed to by pos > If a file can support positioning requests (such as a disk file, as opposed to a terminal), then a file position indicator associated with the stream is positioned at the start (character number zero) of the file, unless the file is opened with append mode in which case it is implementation-defined whether the file position indicator is initially positioned at the beginning or the end of the file. Meaning `fgetpos` mustn't work for files that don't support `positioning requests`, whiles relative offsets using `fseek` could still work.