From: Thomas Beckett <thomas.beckett@...>
Date: 2006-08-30T18:35:30+09:00
Subject: Re: ENV values

On 8/30/06, Frank Hofmann <nospam@lunox.org> wrote:
> Hi all,
>
> I'm working on an ssh script where I'd like to read out console
> dimensions to adjust the output window - the default value of 80x24
> isn't that good. ;)
>
> So I thought it should work by simply reading out the environment
> variables $COLUMNS and $LINES (Linux system). The results in irb were
> what I needed:
>
> ===---===---===---===---===---===
> irb(main):001:0> ENV['COLUMNS']
> => "99"
> irb(main):002:0> ENV['LINES']
> => "32"
> ===---===---===---===---===---===
>
> But in a ruby script these things didn't work anymore. A really simple
> script:
>
> ===---===---===---===---===---===
> #!/usr/bin/ruby -w
>
> puts ENV['USER']
> puts ENV['LINES']
> ===---===---===---===---===---===
>
> This gave me the output:
> frank
> nil
>
> Ok, that didn't work like I've expected it, so here is another way:
>
> ===---===---===---===---===---===
> irb(main):001:0> lines = `echo $LINES`
> => "32\n"
> irb(main):002:0> puts lines
> 32
> => nil
> ===---===---===---===---===---===
>
> Now as ruby script:
>
> ===---===---===---===---===---===
> !/usr/bin/ruby -w
>
> lines = `echo $LINES`
> puts lines
> ===---===---===---===---===---===
>
> Well, also no success. :-/ It gave me only a blank line.
>
> Does anyone have an idea what I could do to get column & line numbers of
> the console window?
>
> Thanks...
>
> Frank
>
> --
> Posted via http://www.ruby-forum.com/.
>
>

If you dont mind depending on ncurses then will something like this work?
you will need the ncurses-ruby package
-----------------------------------------------
require "ncurses.rb"

win = Ncurses.WINDOW.new()
win.getmaxyx(y=[], x=[])
win.delwin()
----------------------------------------------
This should open ncurses mode, get its dimensions - which are handled
correctly and then drop you back out of ncurses.

Note that I havent tried it at all, am a complete newb to Ruby and
found the bits via google, but for 4 lines its worth a try.

Tom