From: Dan George <endege@...>
Date: 2007-09-07T00:25:35+09:00
Subject: Re: Using external text file to do search and replace?

On Aug 22, 5:43 pm, Stefano Crocco <stefano.cro...@alice.it> wrote:
> Alle mercoled� 22 agosto 2007, Dan George ha scritto:
>
>
>
> > I recently started to take an interest in Ruby programming and with
> > the help of some people and by reading Learn to program by Chris Pine
> > I made myself a little program that has come to a halt because I don't
> > know if or how I can use anexternalfile where I store the strings I
> > want to search and replace in text type files.
>
> > This is what I have so far:
>
> > txt_files = Dir.glob('**/*.txt').each do |path|
> > puts path
> > txts = path.to_s
> >   file = File.open(txts).readlines.each { |line|
> >     if line.match(/PROMOS:/)
> >       then line.gsub!(/PROMO1=[A-Za-z0-9]+/, 'PROMO1=some_text')
> >     end }
> >   file2=File.open(txts, "w")
> >   file2.write( file )
> > end
>
> > What I want is to be able to use anexternalfile where I store the
> > values I want to search and replace with "line.gsub!" eg.: "/PROMOn=[A-
> > Za-z0-9]+/, 'PROMOn=some_other_text'".
> > I will need to use RubyScript2Exe because I'm not sure that on some
> > other machines I will have ruby installed and it's easier to just put
> > the strings I want to search and replace in anexternalfile that is
> > located in the same folder as the script or on a predefined path.
>
> > Any ideas, hints, improvements and critiques are highly welcome.
>
> First some comments about your code:
> * path is already a string, so calling to_s on it does nothing.
> * You can replace the File.open(txts).readlines part with
> File.readlines(txts), which is (in my opinion) clearer and doesn't force you
> to remember to close the file (which by the way, you don't do).
> * When you write to file2, you can use the block form of File.open, which
> takes care of closing the file for you.
>
> Here's how what I'd have written:
>
> Dir.glob('**/*.txt').each do |path|
>   lines = File.readlines(path)
>   if line.match(/PROMOS:/)
>     lines.map!{|l| l.gsub(/PROMO1=[A-Za-z0-9]+/, 'PROMO1=some_text')
>   end
>   File.open(path, 'w'){|f| f.write lines}
> end
>
> As you can see, I've also replaced the each/gsub! combination with map!/gsub,
> which, in my opinion makes clearer what you're doing (changing the contents
> of the array).
>
> As for storing the search/replacement pairs on a file, I'd use YAML. It's
> included in the standard library, so there shouldn't be problems with
> RubyScript2Exe. You can get information on yaml for ruby athttp://yaml4r.sourceforge.net/(look in particular at the cookbook and doc
> sections). A simple example could be this:
>
> 'PROMO1=[A-za-z0-9]+': 'PROMO1=some_text'
> 'PROMO2=[A-za-z0-9]+': 'PROMO1=some_other_text'
> ...
>
> When read into rubyusingYAML.load, this would return the following hash:
>
> {
>  'PROMO1=[A-za-z0-9]+' => 'PROMO1=some_text',
>  'PROMO2=[A-za-z0-9]+' => 'PROMO1=some_other_text'
>
> }
>
> You could then create regexpsusingRegexp.new. (Actually, you can also store
> the regexps directly in the yaml file, prefixing them with the
> string !ruby/regexp, but I think the file is easier to read/write this way).
>
> I hope this helps.
>
> Stefano

I tried what you said and it shows it works and I get an Exit code: 0
but nothing is modified.

Here's what I have now:

require 'yaml'
promo = File.open('promo.yaml')
yp = YAML::load_documents(promo) do |item|
txt_files = Dir.glob('**/*.txt').each do |path|
puts path
  file = File.open(path).readlines.each { |line|
    if line.match(/PROMOS/)
      then line.gsub!(item['search'], item['sub'])
    end }
  File.open(path, 'w'){|f| f.write file}
end
end

And my YAML file looks like this:

---
search: /PROMO1=[A-Za-z0-9]+/
sub: PROMO1=some_text

Can anyone please tell me what's wrong with it?