Mimic 'ruby' executable

Rakefile

require "rake/clean"
require "rbconfig"

def compile_c(source, target)
  cflags = RbConfig::CONFIG["CFLAGS"]
  cppflags = RbConfig::CONFIG["CPPFLAGS"]

  hdr_dir = RbConfig::CONFIG["rubyhdrdir"]
  arch_dir = RbConfig::CONFIG["arch"]

  include_dirs = "-I#{hdr_dir}/#{arch_dir} -I#{hdr_dir}"

  cc = ENV.fetch("CC", RbConfig::CONFIG["CC"])

  sh "#{cc} -c #{source} -o #{target} #{cflags} #{cppflags} #{include_dirs}"
end

def link_ruby(objects, target)
  libruby_dir = RbConfig::CONFIG["libdir"]
  libruby = RbConfig::CONFIG["LIBRUBYARG"]

  libs = RbConfig::CONFIG["LIBS"]
  libs_dir = "-L#{libruby_dir} #{libruby} #{libs}"

  cc = ENV.fetch("CC", RbConfig::CONFIG["CC"])

  sh "#{cc} #{objects.join(' ')} -o #{target} #{libs_dir}"
end

rule ".o" => ".c" do |t|
  compile_c t.source, t.name
end

SRCS = FileList["*.c"]
OBJS = SRCS.ext(".o")

file "simple-ruby.exe" => OBJS do |t|
  link_ruby t.prerequisites, t.name
end

CLEAN.include OBJS
CLEAN.include "simple-ruby.exe"

desc "Compile executable"
task :compile => ["simple-ruby.exe"]

task :default => [:compile]

simple.c

#include "ruby.h"

#ifdef HAVE_LOCALE_H
#include <locale.h>
#endif

int
main(int argc, char **argv)
{
#ifdef HAVE_LOCALE_H
	setlocale(LC_CTYPE, "");
#endif

	ruby_sysinit(&argc, &argv);
	{
		RUBY_INIT_STACK;
		ruby_init();
		return ruby_run_node(ruby_options(argc, argv));
	}
}