From: Peter Bailey <pbailey@...>
Date: 2006-04-13T00:24:22+09:00
Subject: Re: Simple substitutions

Ross Bamford wrote:
> On Wed, 2006-04-12 at 22:35 +0900, Peter Bailey wrote:
>> > 	if pages
>> > 	  File.open("psout.txt", "w") { |out| out << "Pages: #{pages}" }
>> > 	end
>> 
>> 
>> Aha. I didn't know about "scan." Just the word alone makes sense for 
>> what I want. And, yes, I found it in the Big Book, on page 617.
>> 
>> What does the "break" do, Ross? Is it just telling RUBY to stop if it's 
>> found what it was scanning for?
> 
> Yes - you can find a bit about it near the end of this page:
> 
> 	http://www.rubycentral.com/book/tut_expressions.html
> 
> Looking at that again, though, I can't imagine why I didn't just write:
> 
> 	if File.read('test1.ps') =~ /\%\%Pages: ([0-9]{1,5})/
> 	  pages = $1
> 	end
> 
> For just a single match.


Yes, the =~ notation certainly seems simpler. Now, I'm pursing this 
further and now I need to look for blank pages in my postscript. These 
are found with a regex, too, a more complex one, but, I've created one 
that works. And, with this search, because there may be more than just 
one, I've created an array and I'm pushing every page number I find 
blank into that array. Cool. I love this stuff. I'm having a bit of 
trouble though printing a simple array.length statement. Please check 
this out:

************************************************
Dir.chdir('c:/scripts/ruby/temp')
blanks = []
File.read("test2.ps").scan(/\%\%Page: [\d()]+ 
(\d{1,5})\n\%\%PageBoundingBox: \d{1,5} \d{1,5} \d{1,5} 
\d{1,5}\n\%\%PageOrientation:/) do
  blanks.push($1)
  number = blanks.length
  blanks.push(" ")
  #break
end

if blanks
  File.open("psout2.txt", "w") { |out| out << "Blank Pages in This PDF: 
#{blanks}\nNo. of Blanks: #number\n" }
end
************************************************


I'm getting this, which I'm extremely proud of, but, it doesn't quite 
make it:

+++++++++++++++++++++++++++++++++++++++++
Blank Pages in This PDF: 46 68 72 80 83
No. of Blanks: #number
+++++++++++++++++++++++++++++++++++++++++

Thanks. If I can just get this, then, I'll streamline my script to take 
advantage of the simple match, like you suggested.


-- 
Posted via http://www.ruby-forum.com/.