From: Ryan Davis <ryand-ruby@...>
Date: 2007-02-11T19:50:51+09:00
Subject: Re: ENV['COLUMNS']


On Feb 10, 2007, at 3:25 AM, pedro mg wrote:

> Hi,
>
> in irb I can have access to ENV['COLUMNS'] for the # of columns in  
> the shell, and works fine.
> But inside a script (ruby script.rb), I can't have access to that  
> hash key and value.
> I've done a:
>
> puts ENV.to_a
>
> and i can not see both COLUMNS and LINES
> What would be the problem ?

COLUMNS isn't exported. You shouldn't be able to see it within your  
irb session without exporting it or doing something else special.

% echo $COLUMNS
80
% ruby -e 'p ENV.keys.grep(/COL/)'
[]
% irb
 >> p ENV.keys.grep(/COL/)
[]
=> nil
 >> ^d

% export COLUMNS
% ruby -e 'p ENV.keys.grep(/COL/)'
["COLUMNS"]
% irb
 >> p ENV.keys.grep(/COL/)
["COLUMNS"]
=> nil
 >> ^d

I suggest you use stty instead.

% ruby -e 'p `stty size`.scan(/\d+/).map { |s| s.to_i }'
[24, 80]