How to post-process the buffer populated by the async `start-process'

How to post-process the buffer populated by the async `start-process'

[Kaushal Modi]

Hello,

I am using a package which starts a command in a subprocess (async) using
`start-process' and the results of the command are dumped in the buffer arg
passed to subprocess.

But the stdout sent to the buffer has ANSI escape codes.

If I manually visit that buffer, and eval (ansi-color-apply-on-region-int
(point-min) (point-max)), I can see the ANSI color codes nicely rendered.

But I cannot figure out how to do that *when* the start-process initiated
command ends *in* the specified stdout buffer.

If I do:

(apply #'start-process ..)
(with-current-buffer buffer
  (ansi-color-apply-on-region-int (point-min) (point-max)) )

.. it of course doesn't work because the a-c-a-o-r-i is getting called
before start-process initiated command ends.

So I somehow need to define a hook that can get triggered when that command
ends, and then call the a-c-a-o-r-i function. But I don't know how.

--
Kaushal Modi

Re: How to post-process the buffer populated by the async `start-process'

[mail]

12.01.2019, 11:36, "Kaushal Modi" <kaushal.modi@gmail.com>:
> Hello,
>
> I am using a package which starts a command in a subprocess (async) using
> `start-process' and the results of the command are dumped in the buffer arg
> passed to subprocess.
>
> But the stdout sent to the buffer has ANSI escape codes.
>
> If I manually visit that buffer, and eval (ansi-color-apply-on-region-int
> (point-min) (point-max)), I can see the ANSI color codes nicely rendered.
>
> But I cannot figure out how to do that *when* the start-process initiated
> command ends *in* the specified stdout buffer.
>
> If I do:
>
> (apply #'start-process ..)
> (with-current-buffer buffer
>   (ansi-color-apply-on-region-int (point-min) (point-max)) )
>
> .. it of course doesn't work because the a-c-a-o-r-i is getting called
> before start-process initiated command ends.
>
> So I somehow need to define a hook that can get triggered when that command
> ends, and then call the a-c-a-o-r-i function. But I don't know how.

Have you tried (info "(elisp) Sentinels")? The info already provides a nice example, here is another example:

(set-process-sentinel
 (start-process "sleep" "*sleep*" "sleep" "3")
 (lambda (_process event)
   (when (string= event "finished\n")
     (message "TODO Do something"))))

> --
> Kaushal Modi

Re: How to post-process the buffer populated by the async `start-process'

[Kaushal Modi]

On Sat, Jan 12, 2019 at 1:32 AM <mail@xuchunyang.me> wrote:

>
> Have you tried (info "(elisp) Sentinels")? The info already provides a
> nice example, here is another example:
>
> (set-process-sentinel
>  (start-process "sleep" "*sleep*" "sleep" "3")
>  (lambda (_process event)
>    (when (string= event "finished\n")
>      (message "TODO Do something"))))
>

I did not know about Sentinels, and your example is much better than that
in the manual :)

Thanks for your help!