From: Stefano Crocco <stefano.crocco@...>
Date: 2008-06-05T02:26:38+09:00
Subject: Re: Beginner: Read file

On Wednesday 04 June 2008, Justin To wrote:
> report = File.open('ReportTxt.txt', 'r') do |L|
>    while line = L.gets
>
>   report.getc.chr
>
>     end
> end

There are at least two problems with your code:
1) you use the variable report in the block, but the variable is assigned a 
value *after* the File.open method returns. This means that when you call 
report.getc inside your block, report is nil, hence the error you're getting 
(by the way, when you ask for help, you should specify what kind of error 
you're getting).
2) You use L.gets to iterate. But: a) gets, with no argument, iterates 
linewise, which means you'll read a character for each line; b) gets moves the 
position in the file, which means that, after L.gets reads the last line of 
the file, you'll get an error.

To achieve what you want, you can use the following code (by the way, capital 
letters in ruby are used for constants, so it's better not to use them for 
block variables):

File.open('ReportTxt.txt', 'r') do |f|
  until f.eof?
    f.getc.chr
  end
end

I hope this helps

Stefano