From: "Eric Schulte" <schulte.eric@gmail.com>
To: Julien Fantin <julienfantin@gmail.com>
Cc: emacs-orgmode@gnu.org
Subject: Re: [babel] ob-C.el annoyances
Date: Fri, 15 Apr 2011 10:24:58 -0600 [thread overview]
Message-ID: <87zknr8osr.fsf@gmail.com> (raw)
In-Reply-To: m2mxjraac9.fsf@gmail.com
Julien Fantin <julienfantin@gmail.com> writes:
> Hi list, hi Eric,
>
> I've been using ob-C to go through the K&R book, and I've noticed a few
> annoyances along the way.
>
> * Use of the captial C identifier
>
> Support functions are defined as ob-C-*. In consequence, I need to
> #+begin_src C to get a block to execute, because #+begin_src c fails
> with "No org-babel-execute function for c!". The problem is that I can't
> edit the block since there is no C-mode. Defining an alias fixed the
> issue, but it doesn't work OOTB, and doesn't feel like a good solution
> at all.
>
I've changed the default value of `org-src-lang-modes' so with the
latest version of Org-mode the "begin_src C" code blocks will use the
appropriate mode without the need to define an alias. Thanks for
pointing out this inconsistency.
>
> Is there a reasoning behind this, or where you, as I suspect, trying to
> define some support functions that would work for both C and C++ ?
>
For a while we had a mix of both "C" and "c" in our function names, and
recently we normalized on "C". It seems we left a few loose ends in
this process.
>
>
> * Feeding text into blocks
>
> This is not directly related to ob-C.el, but I was looking for a way to
> feed some text to a block's STDIN while it was executed by babel. I
> wanted to specifiy this text either inline from the block's header
> arguments or from a dedicated text block.
>
There is currently the option of passing command line arguments to C
code blocks, e.g.,
#+begin_src C :cmdline 1 2 3 4 5 :includes <stdio.h>
int main(int argc, char **argv){
printf("argv[1] %s\n", argv[1]);
return 0;
}
#+end_src
#+results:
: argv[1] 1
However there is no support for piping to/from the STDIN/STDOUT/STDERR
of code blocks. The issue of pipes has come up before (for example with
a robust piping interface, we could stream data between code blocks in
much the same way as piped commands on the command line). Such a change
would require significant work, may require support for asynchronous
code block execution.
While such large projects may make (for example) a good google SOC
project, I don't believe they will be implemented in the near future.
>
> It'd ideally look like this :
>
> ** Inline
>
> #+begin_src c :feed foo bar
> int main(void) {
> while ((c = getchar()) != EOF) {
> putchar(c);
> }
> return 0;
> }
> #+end_src
>
> #+results:
> : foo bar
>
> ** From a text block
>
> #+source: my-stdin
> #+begin_src text
> foo bar
> #+end_src
>
> #+begin_src c :feed my-stdin
> int main(void) {
> while ((c = getchar()) != EOF) {
> putchar(c);
> }
> return 0;
> }
> #+end_src
>
> #+results:
> : foo bar
>
> TL;DR if this is already possible somehow please skip the following and let
> me know :)
>
> I couldn't figure out how to pipe the text from within babel though. So
> I resorted to tangling the text blocks, and redefined
> org-babel-C-execute to use that new header argument :feed. It gets
> prepended to the cmdline in the org-babel-eval function call ; if foo is
> an existing file it gets cat'ed through a pipe to the rest of the
> cmdline in org-babel-eval, otherwise it is simply echo'ed. This is not
> as good as what I described above, but after getting to use it, I really
> think a generalization of this use-case is desirable.
>
> Please let me know whar you think.
>
I agree fully, however I would want to implement piping in such a manner
that it can easily be extended to any language, rather than in a C
specific manner. It sounds like you have a nice solution currently.
Perhaps rather than overwriting the execute function, you could wrap
this up into a new function, and share the code on Worg so others could
incorporate it into their workflow.
Best -- Eric
>
> Regards,
> Julien.
>
>
>
--
Eric Schulte
http://cs.unm.edu/~eschulte/
prev parent reply other threads:[~2011-04-15 16:26 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-15 13:54 [babel] ob-C.el annoyances Julien Fantin
2011-04-15 16:24 ` Eric Schulte [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87zknr8osr.fsf@gmail.com \
--to=schulte.eric@gmail.com \
--cc=emacs-orgmode@gnu.org \
--cc=julienfantin@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this external index
https://git.savannah.gnu.org/cgit/emacs.git
https://git.savannah.gnu.org/cgit/emacs/org-mode.git
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.