From: Justin Rudd <justin.rudd@...>
Date: 2004-09-10T04:55:50+09:00
Subject: Ruby on Windows

Is it just me, or is getting anything other than standard ruby a true
ordeal on Windows?

Now I'm sure everyone is snickering right about now, that's OK.  

Anyway, I'm trying to write a product using Ruby that will be
downloaded and run locally.  I need to support different databases. 
MySQL has native Windows binaries.  Looking for Ruby bindings to MySQL
led me to http://www.tmtm.org/en/mysql/ruby/.  So I download the
archive, extract it, run ruby extconf.rb, and it stops there.

It can't find mysql_query in any of the library paths that it looks
at.  So I look at the log file and see that it is basically generate
mini-C programs and if they compile, the stuff is there.

On Windows, there is a mysqlclient.lib file that it is trying to link
to.  Hm...why would it still show up unresolved?

Fast forward 3 hours of digging through mkmf to figure out how it is
generating paths...  Screw this.  I'll just generate the C file myself
and write my own project to generate the library.  That wasn't too
hard.  Got the project going.  Got the shared library compiled. 
Hm...where do I put the file?  Ah...I put it in the i386-msvcrt
directory in site_ruby.  Hm...everything in there is a .so file. 
OK...I'll rename mine to mysql.so (is this necessary?)

Now I'll go and do this - 

    require 'mysql'

Run this through the interpreter...

Get this...

C:/shared/tools/sdks/ruby/lib/ruby/1.8/i386-mswin32/mysql.so: 127: The
specified procedure could not be found.   - Init_mysql (LoadError)
C:/shared/tools/sdks/ruby/lib/ruby/1.8/i386-mswin32/mysql.so    from
connect.rb:1

Look at my C project, Init_mysql does exist.  But it isn't exported. 
In the Windows world, I have to export functions from DLLS.  So that
things like GetProcAddress work.  So I start off by exporting the one
method.

Rerun the interpreter, no errors.  WOOHOO!!!

So I extend the script to this...

   require 'mysql'

   c = Mysql.new('localhost', 'root', 'my_root_password')

   c.list_dbs.each { |db|
      p db
   }

I get a list of all Databases in MySQL instance.  Try some inserts,
deletes, etc.  Everything seems to be working.

Now here are my problems -
* This took 6 hours
* extconf gave me no ideas that it required a C compiler
* extconf gave me no ideas what was going wrong (I just got a no)

I'm a pretty decent Windows programmer (been doing it for 10+ years
now).  And I think I've got to go through the whole process again to
get Ruby DBI working and SQLLite/Ruby (which I probably won't use
since it is GPL).  And PostgresQL.  But for someone starting out with
Ruby on Windows, would they know they needed a C compiler?  Would they
know they needed to add __declspec(dllexport) to that one function?

Now let's contrast this with Python.  I go to
http://sourceforge.net/projects/mysql-python/ and they have an EXE I
can download, run it, and I can connect to MySQL in under 5 minutes
(after download).

I love Ruby.  And a lot of that love comes from Rails (which I've been
using quite successfully).  But building an app is harder than it
should be.

I'm going to document what I did and post it on my weblog along with
the binary file that I generated.  Hopefully someone else out there
can make use of it.

-- 
Justin Rudd
http://seagecko.org/thoughts/