From: Lyle Johnson <jlj@...>
Date: 2002-04-27T06:59:37+09:00
Subject: Re: Help learning Ruby

> I looked at the online version, and they still don't explain how to do the
> simplest things. I open ruby, and type 'Print "Hello world!"'... Nothing
> happens!!
>     How do you compile/interpret a ruby file?

In the Preface to "Programming Ruby":

    http://www.rubycentral.com/book/preface.html

under the heading "Running Ruby", the authors describe different ways you
can run Ruby (i.e. interactively versus interpreting a program file).
Running Interactive Ruby (IRB) is a good way to get familiar with some of
the basics, before you plunge into your first program. Assuming you've
installed the Windows version, you should be able to start IRB by typing IRB
at the prompt:

    C:\>irb
    irb(main):001:0> puts "Hello, world!"
    Hello, world!
    nil
    irb(main):002:0> exit

Because irb reports the return value of any method you call, you're seeing
both the action from calling puts() -- it prints the string "Hello,
world!" -- as well as the return value of the puts method, which happens to
be nil.

More often, however, you'll save your programs into a text file (with
extension .rb) and then let Ruby interpret that program. For example,

    C:\>ECHO puts "Hello, world!" > hello.rb
    C:\>ruby hello.rb
    Hello, world!
    C:\>

Hope this helps,

Lyle