Time for action - writing a "Hello World" program

1. 1. Let us try to implement the classical "Hello World" program. Open your editor and type in the following lines of code:

   Code Listing 8.1
   #include <octave/oct.h> #1
   #2
   DEFUN_DLD(hello, argv, , "Usage: hello()"){ #3
   octave_value_list retval; #4
   #5
   octave_stdout << "Hello World\n"; #6
   #7
   return retval; #8
   } #9
   

2. 2. Save the file as hello.cc in your working directory. At the Octave prompt, type in the following command:

octave:10> mkoctfile hello.cc

• This compiles the C++ code.

1. 3. Make a call to the function, which is then dynamically linked to the Octave environment:

octave:11> hello()
Hello World

What just happened?

To use the C++ interface and library, we need to include the header oct.h, which is done in line 1 in Code Listing 8.1. In line 3, we set the function name to hello and name the input argument list argv. We do not specify the number of outputs as this is not used and write a small help text string. The help text is...