eio_seek() repositions the offset of the open file associated with
stream, Socket instance, or file descriptor specified by fd to
the argument offset according to
the directive whence.
Parameters
fd
Stream, Socket instance, or numeric file descriptor.
offset
Starting point from which data is to be read.
whence
whence values are:
EIO_SEEK_SET - Set position equal to offset bytes.
EIO_SEEK_CUR - Set position to current location plus offset.
EIO_SEEK_END - Set position to end-of-file plus offset.