From: Dan George <endege@...>
Date: 2007-09-20T03:05:07+09:00
Subject: Re: YAML & readlines & modify text files

On Sep 19, 5:27 pm, Stefano Crocco <stefano.cro...@alice.it> wrote:
> Alle mercoled� 19 settembre 2007, Dan George ha scritto:

> I'm not at all sure I understand correctly what you want to do. I think you
> want to replace the line under
>
> Name-line: Name01
>
> with some text containing a string taken from the Name01 entry in the yaml
> file. Is it correct? If it isn't, then please explain better what you mean.
> Otherwise, read on.
>
> In my opinion, you're storing data in the YAML file in the wrong way, because,
> at each iteration, name contains only one pair of name/replacement string,
> which forces you to iterate over all the files for each document in the YAML
> file (and also makes the replacing code more complicated). I think your YAML
> file should contain a single hash, with the names as keys and the replacement
> strings as values:
>
> ---
> Name01: N01
> Name02: N02
>
> Then, you can do the following (untested)
>
> require 'yaml'
> lnk = 'blabla.something.'
> op = '&=bla'
> hash = File.open('name.yaml'){|f| YAML.load f}
> Dir.glob('**/.txt').each do |path|
>   lines = File.readlines(path)
>   lines.each_with_index do |line, i|
>     if line.match(/Link-line/)
>       match = lines[i-1].match(/Name-line:\s(.*)$/)[1]
>       line.gsub!(/Link-line.*/, 'Link-line: '+ lnk+hash[match[1]]+
>              op) if match and hash.has_key?(match[1])
>     end
>   end
>   File.open(path,'w'){|f| f.write lines}
> end
>
> When iterating on the lines, the block is passed not only the line, but also
> the line number. This way, when you meet a Link-line line, you can access the
> corresponding name-line using its index. It then matches the previous line
> with a regexp to extract the name from it and stores the result in the match
> variable. If match is not nil (i.e if the name line had the expected format)
> and the name is included in hash, the replacement is performed (of course,
> you can skip this test if you're confident enough in the format of the files
> and in the contents of the yaml file)
>
> I hope this helps
>
> Stefano

You are correct, that is what I want!

I tryied what you suggested but I get some weird errors:

new.rb:45: undefined method `[]' for nil:NilClass (NoMethodError)
	from D:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
`each_with_index'
	from new.rb:43:in `each'
	from new.rb:43:in `each_with_index'
	from new.rb:43
	from new.rb:41:in `each'
	from new.rb:41

Line 45 is:       match = lines[i-1].match(/Name-line:\s(.*)$/)[1]
Line 43 is:       lines.each_with_index do |line, i|
Line 41 is:       Dir.glob('**/*.jad').each do |path|

I don't get it, as far as I can tell the code is ok...