Execute a function with arguments from the commande-line

add.m

#!/usr/bin/octave --silent
a = str2num(argv(){1});
b = str2num(argv(){2});


printf("%d\n", a + b);

add_example.m

#!/usr/bin/octave --silent
a = str2num(argv(){1});
b = str2num(argv(){2});

function result = add (a, b)
  result = a + b;
endfunction

printf("%d\n", add(a , b));

I run the script by ./add_example.m 23 43, the result is 66 as expected.
Make sure that the file add_example.m is executable by calling chmod +x ./add_example.m.