From: Stefano Crocco <stefano.crocco@...>
Date: 2012-05-13T01:02:49+09:00
Subject: Re: Beginner's questions

Il giorno Sun, 13 May 2012 00:34:13 +0900
Manfredi Pivetta <lists@ruby-forum.com> ha scritto:

> Hello everyone.
> I've recently picked up programming languages yet again, and since I've
> spent some time on Ruby in the past already, I've decided to start from
> here. However, I've encountered some problems. I've gone through
> at least three tutorials already, but they are kind of useless at this
> stage for me because they all focus on teaching the syntax and how to
> code, while I'm stuck mostly on the tools and libraries. So, here are
> my questions; feel free to redirect me towards a proper tutorial if you
> wish (as long as the tutorial actually has the information I need...).
> 
> First question. How do I compile Ruby code on Linux?

You don't. Ruby is an interpreted language (like shell script, for example) so
you don't need to compile a program to use it. From a terminal you just write:

ruby myscript.rb

and it'll run. You can also add the line

#!/usr/bin/ruby

at the beginning of the script, make it executable (using chmod) and run it as

./myscript.rb


> 
> Second question. How do I work with a graphic interface? Is there a
> library? If there is a library, is there a reference manual for the
> library? I don't require big things, but I've never been able to
> actually produce a graphical output, and tutorials do not help in any
> meaningful way. I've learned to create even quite complex programs in C,
> but they were always on the terminal and the most interesting graphical
> output command I had was printf. Since I'm trying to write a program for
> some elementary kids, I'd rather avoid the terminal altogether.

Ruby comes with bindings to the Tk library. You can find some documentation
at [1]. There are also bindings for other graphics libraries, such as Qt [2],
Gtk [3] and WxWidgets [4]. You can most likely find packages for them using
your distribution's package manager.

> Third question. If I compile a ruby program, how can I make sure that
> double clicking on it will make it run properly (and activate the above
> mentioned user interface)? Again, I'm used to executing programs from
> the terminal but I'd rather have something much much simpler for this
> project. Do you have any advice?

That depends on the desktop environment you use.

> I understand these are some pretty stupid questions, but they got me
> stuck for quite a while and I have noone to ask them to. :)
> 

[1] http://www.tkdocs.com/tutorial/index.html
[2] http://techbase.kde.org/Development/Languages/Ruby
[3] http://ruby-gnome2.sourceforge.jp/
[4] http://wxruby.rubyforge.org/wiki/wiki.pl