Thanks for replying.
However, I cannot change to *shell* buffer when ispell is running.  It
seems that ispell operates under special mode where the keys are redefined
and the command C-x b to switch to other buffers doesn't work.

On Sat, Feb 11, 2012 at 3:40 AM, Peter Dyballa <Peter_Dyballa@web.de> wrote:

>
> Am 11.2.2012 um 02:05 schrieb Shiyuan:
>
> > 2. What is the path of the private dictionary of ispell used by emacs?
>
> Presumingly ~/.ispell_<language>. This name is also mentioned when ispell
> has finished and learned at least one new word.
>
>
> WRT your first problem: when ispell has started to check the buffer and
> stopped at a misspelled word, change to *shell* buffer and try to find out
> (with pstree, ps) what are the arguments and what is the environment in
> which ispell runs. (With lsof you could also check which files it has
> opened.) Record these findings, save them in a file. Now try it also when
> you invoke ispell the other way. After having saved the new findings,
> perform a comparison. Some difference should exist...
>
> --
> Greetings
>
>  Pete
>
> There is no national science just as there is no national multiplication
> table; what is national is no longer science.
>                                – Anton Checov
>
>