From: Stefano Crocco <stefano.crocco@...>
Date: 2007-09-20T17:51:53+09:00
Subject: Re: YAML & readlines & modify text files

Alle gioved� 20 settembre 2007, Dan George ha scritto:
> On Sep 20, 1:41 am, Stefano Crocco <stefano.cro...@alice.it> wrote:
> > Alle gioved� 20 settembre 2007, Dan George ha scritto:
> > > On Sep 20, 12:39 am, Stefano Crocco <stefano.cro...@alice.it> wrote:
> > > > Alle mercoled� 19 settembre 2007, Dan George ha scritto:
> > > > > CATEG being another line inside the text files... and the problem
> > > > > might be because the Name-line isn't always above the Link-line. I
> > > > > could have n lines between or below, what I'm trying to say is that
> > > > > I don't know where the Name-line is inside the texts files.
> > > >
> > > > This changes everything. I assumed (according to the example lines
> > > > you posted) that each Link-line had the corresponding Name-line above
> > > > it. But, if there isn't a relation between the position of the two
> > > > kind of lines, how can you know what to put in the link line? I mean,
> > > > what is the relation which connects a Link-line and the corresponding
> > > > Name-line? Since (from what you say now) the position of the two kind
> > > > of lines are random (as far as this problem is concerned, at any
> > > > rate) are you able, given a single Link-line, to understand which is
> > > > the corresponding Name-line? If yes, how? Whithout knowing this, I
> > > > can't help you.
> > > >
> > > > Stefano
> > >
> > > All I can say is that in each text file there will only be one Name-
> > > line and one Link-line. The only connection between this 2 lines is
> > > that the Link uses the shorter version of what is written in the Name-
> > > line (i.e. if the Name-line: New York the Link line will use NY)
> > >
> > > Isn't it possible to read the Name-line, take the correspond value
> > > from the YAML file, store it in a variable (string?) inside the code
> > > and then use it in the Link-line, when going to the next text file
> > > read again the Name-line and take the value from YAML and so on...
> >
> > If each file contains only one Name-line and one instance of the
> > corresponding Link-line, this should work:
> >
> > require 'yaml'
> >
> > lnk='blabla.something.'
> > op = '&=bla'
> > hash = File.open('name.yaml'){|f| YAML.load f}
> >
> > Dir.glob('**/*.txt').each do |f|
> >   lines = File.readlines f
> >   name = nil
> >   link_idx = nil
> >   lines.each_with_index do |l, i|
> >     if l.match(/Name-line:\s+(.*)$/) then name $1
> >     elsif l.match(/Link-line/) then link = i
> >     end
> >     break if name and link_idx
> >   end
> >   if name
> >     rep = hash[name]
> >     if rep
> >       lines[link_idx]="Link-line: #{lnk}#{rep}#{op}"
> >       File.open(f, 'w'){|of| of.write lines}
> >     else puts "name.yaml doesn't contain an entry for #{name} (file
> > #{f})" end
> >   else puts "Couldn't find a Name line in file #{f}"
> >   end
> > end
> >
> > For each file, it loops each line looking for a Name-line or a Link-line.
> > When it finds the former, it stores the name in the name variable; when
> > it finds the latter, it stores its index in the link_idx variable. When
> > both are found, the loop stops (no point in examining the remaining
> > lines). If a name has been found and it corresponds to an entry in the
> > hash, the line with index link_idx is replaced with a new one (I removed
> > the call to gsub!, since we're rebuilding the entire line,  but you can
> > put it back, if you need it), then the array is written to the file. If
> > the Name-line wasn't found, or if the hash doesn't contain an entry for
> > it, an error message is printed on screen and the next file is processed.
> >
> > I hope this helps
> >
> > Stefano
>
> Thanks for your reply Stefano!
>
> I had to do:
>           link_idx = nil.to_i
> otherwise I would get this error: `[]': no implicit conversion from
> nil to integer (TypeError)
>
> And it seems to be working but if I use this:
>           lines[link_idx]="Link-line: #{lnk}#{rep}#{op}"
> the Name-line is removed and is replaced by the "Link-line:
> #{lnk}#{rep}#{op}" but the old Link-line = 0 is kept too.
>
> If I use
>          lines[link_idx].gsub!(/Link-line.*/, 'Link-line: '+lnk+rep
> +op)
> nothing happends, no errors, no modified files, no nothing.
>
> I don't see anything wrong with the gsub! so what might be the problem?

Another couple of mistakes on my part, I'm afraid. This should work

require 'yaml'

lnk='blabla.something.'
op = '&=bla'
hash = File.open('name.yaml'){|f| YAML.load f}

Dir.glob('**/*.txt').each do |f|
  lines = File.readlines f
  name = nil
  link_idx = nil
  lines.each_with_index do |l, i|
    #added missing = between name and $1
    if l.match(/Name-line:\s+(.*)$/) then name = $1
    #changed link = i to link_idx = i
    elsif l.match(/Link-line/) then link_idx = i     
    end
    break if name and link_idx
  end
  #checking that also link_idx is not nil
  if name and link_idx
    rep = hash[name]
    if rep 
      lines[link_idx]="Link-line: #{lnk}#{rep}#{op}"
      File.open(f, 'w'){|of| of.write lines}
    else puts "name.yaml doesn't contain an entry for the name #{name}"
    end
  #changed the error message
  else puts "Name or Link line are missing in file #{f}"
  end
end

Stefano