Re: [O] babel :results output and format of output

[Sean O'Halpin]

On Sun, Feb 24, 2013 at 10:50 AM, D M German <address@hidden> wrote:
>
> hi everybody,
>
>
> I have been testing babel with perl and I am very puzzled by the
> following:
>
>
> Say I have the following script that outputs 10 numbers. org/babel wraps
> it as a begin_example
>
>
> #+begin_src perl :results output
> for (my $i=0;$i<10;$i++) {
>   print "$i\n";
> }
> #+end_src
>
> #+RESULTS:
> #+begin_example
> 0
> 1
> 2
> 3
> 4
> 5
> 6
> 7
> 8
> 9
> #+end_example
>
>
> But if my script only outputs 9 lines then the format is not wrapped by
> #+begin_example, and instead is prefixed by :
>
> #+begin_src perl :results output
> for (my $i=0;$i<9;$i++) {
>   print "$i\n";
> }
> #+end_src
>
> #+RESULTS:
> : 0
> : 1
> : 2
> : 3
> : 4
> : 5
> : 6
> : 7
> : 8
>
> Is this behaviour expected? Is the threshold at which it happens
> configurable?

Yes - it's controlled by =org-babel-min-lines-for-block-output= in
lisp/ob-core.el:

#+BEGIN_QUOTE
(defvar org-babel-min-lines-for-block-output 10
  "The minimum number of lines for block output.
If number of lines of output is equal to or exceeds this
value, the output is placed in a #+begin_example...#+end_example
block.  Otherwise the output is marked as literal by inserting
colons at the starts of the lines.  This variable only takes
effect if the :results output option is in effect.")
#+END_QUOTE

Regards,
Sean