Capturing output from C/C++

Capturing output from C/C++

[Roger Mason]

Hello,

I have a short C++ program:

#+BEGIN_SRC cpp :flags -lm :results output
#include <iostream>
#include <fstream>
#include <cmath>		// for ceil
#include <cstdlib>		// for atof

  double f (double fv, double o, int i) {
    return fv / 2.0 + (1.0 - o) * fv * i;
  }

int num (double d, double fv, double o) {
  return (int)ceil( d / ((1.0 - o) * fv ));
  }

int main (int argc, char* argv[]) {
    if ( argc < 6 ) {
      std::cout << "Usage:\n" << std::endl;
      std::cout << "grid w fovx ox h fovy oy\n" << std::endl;
      return 1;
    }
...
#+END_SRC

that outputs some data to stdout.

So far I have not been able to capture the output of the program back
into to my org buffer.

Is that possible and, if so, how?

Thanks,
Roger
Org-mode version 8.2.6

Re: Capturing output from C/C++

[John Kitchin]

I think you need to tangle the file, compile it and run the executable
in a shell block.

Here is a Fortran example:

http://kitchingroup.cheme.cmu.edu/blog/2014/02/04/Literate-programming-example-with-Fortran-and-org-mode/

I have done similar things with C, java, etc... before.

I don't know of a built in way to type C-c C-c and have it do all those
things for you.


Roger Mason writes:

> Hello,
>
> I have a short C++ program:
>
> #+BEGIN_SRC cpp :flags -lm :results output
> #include <iostream>
> #include <fstream>
> #include <cmath>		// for ceil
> #include <cstdlib>		// for atof
>
>   double f (double fv, double o, int i) {
>     return fv / 2.0 + (1.0 - o) * fv * i;
>   }
>
> int num (double d, double fv, double o) {
>   return (int)ceil( d / ((1.0 - o) * fv ));
>   }
>
> int main (int argc, char* argv[]) {
>     if ( argc < 6 ) {
>       std::cout << "Usage:\n" << std::endl;
>       std::cout << "grid w fovx ox h fovy oy\n" << std::endl;
>       return 1;
>     }
> ...
> #+END_SRC
>
> that outputs some data to stdout.
>
> So far I have not been able to capture the output of the program back
> into to my org buffer.
>
> Is that possible and, if so, how?
>
> Thanks,
> Roger
> Org-mode version 8.2.6

--
Professor John Kitchin
Doherty Hall A207F
Department of Chemical Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
412-268-7803
@johnkitchin
http://kitchingroup.cheme.cmu.edu

Re: Capturing output from C/C++

[Thierry Banel]

It might be due to the return 1; statement.
Change it to return 0; and try again.


Le 05/03/2015 17:27, Roger Mason a écrit :
> Hello,
>
> I have a short C++ program:
>
> #+BEGIN_SRC cpp :flags -lm :results output
> #include <iostream>
> #include <fstream>
> #include <cmath>		// for ceil
> #include <cstdlib>		// for atof
>
>   double f (double fv, double o, int i) {
>     return fv / 2.0 + (1.0 - o) * fv * i;
>   }
>
> int num (double d, double fv, double o) {
>   return (int)ceil( d / ((1.0 - o) * fv ));
>   }
>
> int main (int argc, char* argv[]) {
>     if ( argc < 6 ) {
>       std::cout << "Usage:\n" << std::endl;
>       std::cout << "grid w fovx ox h fovy oy\n" << std::endl;
>       return 1;
>     }
> ...
> #+END_SRC
>
> that outputs some data to stdout.
>
> So far I have not been able to capture the output of the program back
> into to my org buffer.
>
> Is that possible and, if so, how?
>
> Thanks,
> Roger
> Org-mode version 8.2.6
>
>

Re: Capturing output from C/C++

[Nick Dokos]

Roger Mason <rmason@mun.ca> writes:

> Hello,
>
> I have a short C++ program:
>
> #+BEGIN_SRC cpp :flags -lm :results output
> #include <iostream>
> #include <fstream>
> #include <cmath>		// for ceil
> #include <cstdlib>		// for atof
>
>   double f (double fv, double o, int i) {
>     return fv / 2.0 + (1.0 - o) * fv * i;
>   }
>
> int num (double d, double fv, double o) {
>   return (int)ceil( d / ((1.0 - o) * fv ));
>   }
>
> int main (int argc, char* argv[]) {
>     if ( argc < 6 ) {
>       std::cout << "Usage:\n" << std::endl;
>       std::cout << "grid w fovx ox h fovy oy\n" << std::endl;
>       return 1;
>     }
> ...
> #+END_SRC
>
> that outputs some data to stdout.
>
> So far I have not been able to capture the output of the program back
> into to my org buffer.
>
> Is that possible and, if so, how?
>

You call your program with no arguments, which means that it returns 1,
which is interpreted as an error. Try returning 0 or fix the call so
that it goes through the path that returns 0.

Nick