From: Rainer <wolf.rainer@...>
Date: 2007-10-31T03:05:10+09:00
Subject: The return of the son of Umlaute

Hello everybody,

I'd like to get a hint about a little Ruby problem I'm dealing with.
In my spare time I wrote a little Ruby program with a plain text
interface for I/O. I use Windows XP (yeah, I know :-) with Ruby 1.8.6.

Now for the problem: In Germany, we have letters called "Umlaute",
which are rarely used in the English language. An example you might be
familiar with is the name ot the rock band "Motörhead". (No, I don't
know their music, it's just an example.)

Now, if I wanted to save a file with the single line "Motörhead", I
would want to do something like this:

irb(main):001:0> a_string = "Motörhead"
=> "Mot\224rhead"
irb(main):002:0> a_file = File.new("test.txt", "w")
=> #<File:test.txt>
irb(main):003:0> a_file << a_string
=> #<File:test.txt>
irb(main):004:0> a_file.close
=> nil
irb(main):005:0>

However, when I open "test.txt" with a text editor, I get this result:

Mot"rhead

When I read a file with the correct spelling...

irb(main):006:0> puts File.open("test.txt", "r").readlines

..I get this result:

Mot÷rhead
=> nil

I've tried to use Iconv, but I don't know the names of the character
sets I have to use. To solve the problem, I've written this little
script..

def umlaute (line, replace_dict = File_To_Shell)
  changed_line = line.clone
  replace_dict.each_pair {|from, to| changed_line.sub!(from, to)}
  changed_line
end

...which uses two hashes in order to replace the "offending"
characters back and forth:

File_To_Shell = {
  /\344/ => "\204", # "ä"
  /\366/ => "\224", # "ö"
  /\374/ => "\201",  # "ü"
  /\304/ => "\216", # "Ä"
  /\326/ => "\231", # "Ö"
  /\334/ => "\232",  # "Ü"
  /\337/ => "\341"  # "ß"
}

Shell_To_File = {
  /\204/ => "\344", # "ä"
  /\224/ => "\366", # "ö"
  /\201/ => "\374",  # "ü"
  /\216/ => "\304", # "Ä"
  /\231/ => "\326", # "Ö"
  /\232/ => "\334",  # "Ü"
  /\341/ => "\337"  # "ß"
}

This seems to work, but I consider this a rather ugly workaround and
hardly a decent solution, since it forces me to type..

a_string = umlaute("Motörhead")

..or even..

puts umlaute("Motörhead")

..whenever I have a "strange" character or two in my strings. Any help
is appreciated.

Thanks in advance,

Rainer Wolf