Running another ruby script from a ruby script

Question

In ruby, is it possible to specify to call another ruby script using the same ruby interpreter as the original script is being run by?

For example, if a.rb runs b.rb a couple of times, is it possible to replace

system("ruby", "b.rb", "foo", "bar")

with something like

run_ruby("b.rb", "foo", "bar")

so that if you used ruby1.9.1 a.rb on the original, ruby1.9.1 would be used on b.rb, but if you just used ruby a.rb on the original, ruby would be used on b.rb?

I'd prefer not to use shebangs, as I'd like it to be able to run on different computers, some of which don't have /usr/bin/env.

Edit: I didn't mean load or require and the like, but spawning new processes (so I can use multiple CPUs).

Answer 1

require "b.rb"

will execute the contents of b.rb (you call leave off the ".rb", and there is a search path). In your case, you would probably do something like:

a.rb:

require "b.rb";
b("Hello", "world")

b.rb:

def b(first, second)
  puts first + ", " + second
end

Note that if you use require, Ruby will only load and execute the file once (every time you call load it will be reloaded), but you can call methods defined in the file as many times as you want.

As things get more complex, you will want to move towards an object-oriented design.

EDIT: In that case, you should look into Ruby threading. A simple example is:

a.rb:

require "b";
t1 = Thread.new{b("Hello", "world");}
t2 = Thread.new{b("Hello", "galaxy");}
t1.join
t2.join

b.rb:

def b(first, second)
  10.times {
    puts first + ", " + second;
    sleep(0.1);
  }
end