call-process writing to the wrong buffer

call-process writing to the wrong buffer

[Matthias Pfeifer]

I frequently have to look into a binary file and want to translate it into
text by using an external program. I came up with this snippet from which I
had expected that it opens a new buffer, selects that buffer and writes
into it the output of this external program:

(defun mp/show-x509 ()
  (interactive)
  (let ((cert-file (buffer-file-name))
        (right-window (split-window-right))
        (openssl-buffer (generate-new-buffer (generate-new-buffer-name
"*openssl*"))))
    (select-window right-window)
    (set-window-buffer nil openssl-buffer)
    (call-process "openssl" nil t (list openssl-buffer t) "x509" "-text"
"-noout" "-in" cert-file)))

However I must have some misunderstanding here. The output of call-process
is in fact inserted into the window on the left (left when assuming there
is only one window in the frame when caling mp/show-x509). And I really do
not have a clue whats wrong.

matthias

Re: call-process writing to the wrong buffer

[Joost Kremers]

On Wed, Nov 02 2016, Matthias Pfeifer wrote:
> I frequently have to look into a binary file and want to 
> translate it into
> text by using an external program. I came up with this snippet 
> from which I
> had expected that it opens a new buffer, selects that buffer and 
> writes
> into it the output of this external program:
>
> (defun mp/show-x509 ()
>   (interactive)
>   (let ((cert-file (buffer-file-name))
>         (right-window (split-window-right))
>         (openssl-buffer (generate-new-buffer 
>         (generate-new-buffer-name
> "*openssl*"))))
>     (select-window right-window)
>     (set-window-buffer nil openssl-buffer)
>     (call-process "openssl" nil t (list openssl-buffer t) "x509" 
>     "-text"
> "-noout" "-in" cert-file)))
>
> However I must have some misunderstanding here. The output of 
> call-process
> is in fact inserted into the window on the left (left when 
> assuming there
> is only one window in the frame when caling mp/show-x509). And I 
> really do
> not have a clue whats wrong.

You probably want:

    (call-process "openssl" nil (list openssl-buffer t) t "x509" 
    "-text" "-noout" "-in" cert-file)

(Swap third and fourth argument.)

-- 
Joost Kremers
Life has its moments

Re: call-process writing to the wrong buffer

[Matthias Pfeifer]

I was overlooking the obvious...

Many thanks!