seek

Repositions the offset of the stream this to the argument offset according to the directive whence as follows:

SET: Seek offset bytes relative to the beginning (bound_start) of the stream.

CUR: Seek offset bytes relative to the current offset of the stream.

END: Seek offset bytes relative to the end of the stream ( bound_end if non-negative).

Parameters:

this	a Stream
offset	positional offset
whence	seek directive

Returns:

the resultant position on success or %-1 on fail.