From: John Maclean <info@...>
Date: 2006-01-30T14:30:46+09:00
Subject: creating file names with string

Hey chaps,

# A script to ask a user for a string and use it to grep through a
file. My first version works. 

# It was suggested to turn the constants into objects whilst chatting on
ruby-lang.  Please compare the two methods
(excuse the pun). What's wrong with using constants and what am I doing
wrong in my OO version?


#first version using constants

DataDir= "/home/jayeola/bin/acid/data/lookups/"
DataFile = "lookup_assetype.txt"
Lookup = File.join(DataDir, DataFile)

def usage
  screen = "type some letters in the word"
end

def grabber
  # grab first couple letters and grep thru file
  xx = gets.chomp!
  File.open("#{Lookup}") do |test|
    test.each do |line|
      puts line if line =~ /#{xx}/
    end
  end
end

puts usage
grabber

# This doesn't work. The "object" way...


def usage
  screen = "type a few letters containing the word"
end

i = Greppa.new("{@datadir}", "{@datafile}")
i.inspect
puts usage
puts lookup

# filelocations
class Greppa
  def initialize(datadir, datafile )
    @datadir= "/home/jayeola/bin/acid/data/lookups/"
    @datafile = "lookup_assetype.txt"
    @lookup = File.join(@datadir, @datafile)
  end
end


def grabber
  lookup = File.join("{@datadir}", "{@datafile}")
  # grab first couple letters and grep thru file
  xx = gets.chomp!  
  File.open("#{lookup}") do |test|
    test.each do |line|
      puts line if line =~ /#{xx}/
    end
  end 
end
#
i = Greppa.new("{@datadir}", "{@datafile}")
i.inspect
puts usage
puts lookup


-- 
John Maclean
MSc (DIC)
07739 171 531