From: Vincent Fourmond <vincent.fourmond@9online.fr>
Date: 2006-11-08T01:14:39+09:00
Subject: Re: Why am I getting this string error?

Peter Bailey wrote:
> Can someone explain to me why I'm getting the error below for this part 
> of a script? It doesn't seem to like line 24, the scan line, but, I've 
> got this same code being used for other needs and it doesn't complain at 
> all there.

> 23    file_contents = File.read(psfile)
> 24    file_contents.scan(/\%\%Pages: (\d{1,5})[ ]+\n/) do
> 28      file_contents << "\%\%Blank page for Asura.\n\%\%Page:
> 32      end
> ...
> 
> getting this error:
> 
>> rubyw indexpagecounts_6x9.rbw
> indexpagecounts_6x9.rbw:24:in `scan': string modified (RuntimeError)
> 	from indexpagecounts_6x9.rbw:24
> 	from indexpagecounts_6x9.rbw:20:in `each'
> 	from indexpagecounts_6x9.rbw:20
>> Exit code: 1

  You're modifying file_contents during scan, so scan gets confused.
from what I see, you'd better use gsub! with a block, since, if I
understood your point, you are basically inserting text where you detect
something.

	Vince

-- 
Vincent Fourmond, PhD student
http://vincent.fourmond.neuf.fr/