Org-mode: use result from babel in another programming language

Question

Org and babel in emacs are awesome. Is it possible to have something like this:

Here is a C code

#+BEGIN_SRC C :output results 
  #include <stdio.h>
  int main(){
    int x = 5.00;
    int i;
    for (i = 0; i < 5; ++i) {
      x = x+1;
    }
    printf("X = %d", x);
    return 0;
  }
#+END_SRC

Then I would like to use this X in another programming environment, say Python and do something else with this X.

#+BEGIN_SRC python :output resultPython
print(x+2)
#+END_SRC

It is not as simple as just directly use the variable X. Is it possible to do this in Babel?

Answer 1

That is one of the main pillars of babel.

Give the C source block a name if you want to use in the variable assignments of another source block.

You input the result of the C source block to another source block by the :var header argument.

The python source blocks are described at https://orgmode.org/worg/org-contrib/babel/languages/ob-doc-python.html. The output of a non-session python block is its return value.

#+NAME: myCSrcBlock
#+BEGIN_SRC C
  #include <stdio.h>
  int main(){
    int x = 5.00;
    int i;
    for (i = 0; i < 5; ++i) {
      x = x+1;
    }
    printf("%d", x);
    return 0;
  }
#+END_SRC

#+RESULTS: myCSrcBlock
: 10

#+RESULTS:
: X = 10

Then I would like to use this X in another programming environment, say Python and do something else with this X.

#+BEGIN_SRC python :var x=myCSrcBlock
return x+2;
#+END_SRC

#+RESULTS:
: 12