ruby-winsize Build Status

winsize is a small library that lets you get and set the winsize of a tty.


winsize adds 2 methods: winsize and winsize= to IO that allows you to control the size of a tty window. Mainly used with pty to deal with executables that word wrap (i.e. top). If you are using ruby 1.9.3 this gem is not needed. require "io/console" provides the same functionality.


add this line your application's Gemfile:

gem "winsize"

And then execute:

$ bundle install

Or install it yourself as:

$ gem install winsize


Get the size of the terminal

require "winsize"

rows, cols = $stdout.winsize
puts "Your terminal is #{cols}x#{rows}"

Set the size of a pty terminal

require "pty"
require "winsize"

size =, 180)
input, output, pid = PTY.spawn
output.winsize = size

Reacting to a resized terminal

You may want to combine winsize and catching the SIGWINCH signal so you can react when the terminal has been resized.

require "winsize"

puts "Terminal size is #{$stdout.winsize.cols}x#{$stdout.winsize.rows}"

Signal.trap(:WINCH) do
  puts "Terminal resized to #{$stdout.winsize.cols}x#{$stdout.winsize.rows}"

loop { sleep(10) }

io/console API compatible

require "winsize"

$stdout.winsize.to_ary # => [32, 180]
$stdout.winsize = [32, 180]


Fork, branch & pull request.