Re: call-process and incremental display of output

[Florian Weimer]

* Stefan Monnier:

>> (defun fw/get-new-mail ()
>>   (interactive)
>>   (let* ((buffer (get-buffer-create "*mbsync*"))
>>       (status (with-current-buffer buffer
>>                 (delete-region (point-min) (point-max))
>>                 (call-process "bash" nil (list buffer t) t
>>                               "-c" "
>> for x in {1..5} ; do
>>   date
>>   sleep 1
>> done
>> "))))
>>     (unless (= 0 status)
>>       (switch-to-buffer buffer)
>>       (error "mbsync exit with status %d" status))))
>>
>> When I run this using ‘M-x fw/get-new-mail RET’, the buffer is not
>> displayed, even though I passed t for the display argument.
>
> The argument to call-process controls whether redisplay will take place
> while the process is running, so you indeed need to set it to t in your
> case, but it doesn't affect which buffer is shown in which window, and
> you only display the buffer in the switch-to-buffer which is performed
> after call-process is over.

Ahh, that explains it.

> IOW, just move your switch-to-buffer (which you should also change to
> pop-to-buffer or something like that if you want your code to be robust)
> to before the call to call-process.

I see.  Further questions: How can I restore the window configuration
after the process terminates?  Is there something similar to
save-excursion?

How can I make the displayed buffer to scroll to the end?

I probably shuld rethink this approach and just launch an xterm or
something. 8-)

Thanks,
Florian