flush_before_seek  358 io.c           #define io_seek(fptr, ofs, whence) (io_unset_eof(fptr), lseek(flush_before_seek(fptr)->fd, ofs, whence))
flush_before_seek  359 io.c           #define io_tell(fptr) lseek(flush_before_seek(fptr)->fd, 0, SEEK_CUR)