From: "gabriele renzi <surrender_it@" <remove@...>, yahoo.it@...
Date: 2002-09-29T23:11:53+09:00
Subject: How to load vars from users' app.conf (quite long)

Hi gurus,

I'm writing a simple app that needs to read a configuration file in
the common unix format

#that is a comment
var_name=var

Well, the question is : what's the better way to load those global
variables?
i thought 5 ways:
---------
1: clear, long, unpretty
	
#I like adding methods to existing classes
class File
  def read_val
    readline.split("=")[1].sub("\n",'')
  
  end
end

file=File::new "app.conf"
	$var1=file.read_val
   	$var2=file.read_val
        ...
        $varN=file.read_val
	file.close

(and what if the user leaves an empty line, or switches them ?)
---------
2: shameless ripped from rbot/config.rb
 IO.foreach("app.conf") do |line|
          next if(line =~ /^\s*#/)
          if(line =~ /(\S+)\s+=\s+(.*)$/)
            $1 = $2 if($2)
          end
---------
3: shorter, but using eval 
IO.foreach ("app.conf") {|line|  eval ("$#{line}") unless
line=~/(^#|^\s*$)/ }

(I supposed even the unless statement could be avoided, but I'm
getting a SyntaxError.
Anyway, I heard using eval is Wrong(tm), but what are the problems in
a use case like this?)

#these 2 ideas came out while I was writing this mesg:
---------
4: huge case , kind of 
	case line
	 when line =~/varX=(.*)/
		$varX=$1
	 ...
	end

(the user could reverse the order, delete some parameter, 
 adding useless ones and all should work anyway) 

---------
5: quicky and risky:

require "app.conf"

(I lose the tainted nature of input this way, actually I 
 should hope the user won't load a var like `rm -fr` :-)