Testing Ruby FFI - Calling from C and Ruby

main.c

#include <stdio.h>
#include "mylibrary.h"

int main(){
    
    char x[10];
    double d = 10.0;
    double *dp = &d;
    double dd[3];
    printf("tf0 - %lf\n",calculate_something(1,2.33));
    printf("tf1 - %s\n", test_function_1("hello"));
    printf("tf2 - %d\n", test_function_2(10.0,dp,x));
    test_function_3();
    test_function_4(dd);
    printf("tf4 - %lf, %lf, %lf", dd[0], dd[1], dd[2]);
    return 1;
}

main.rb

require 'ffi'
require './mylibrary.rb'

objptr = FFI::MemoryPointer.new(:double).put_double(0, 10.0)
p objptr.get_double(0)
dd = FFI::MemoryPointer.new(:double,4, true)


c = MyLibrary.calculate_something(TESTVAR, 98.6) # note FFI handles literals just fine
d = MyLibrary.test_function_1("hello world")
e = MyLibrary.test_function_2(10.0,objptr,"hello")
MyLibrary.test_function_3
MyLibrary.test_function_4(dd)
puts "tf0 - #{c}"
puts "tf1 - #{d}"
puts "tf2 - #{e}"
arr = dd.get_array_of_double(0, 3)
puts "tf4 - #{arr}"