From 78e3185a20d9307c98fecca6d3bacfb8f2c271b8 Mon Sep 17 00:00:00 2001
From: naruse <naruse@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Fri, 12 Oct 2012 16:03:41 +0000
Subject: [PATCH] use tty(1) to check if /dev/tty is usable or not

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@37169 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 test/ruby/test_io.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/ruby/test_io.rb b/test/ruby/test_io.rb
index 130d6afe3e..ddc5f8cb00 100644
--- a/test/ruby/test_io.rb
+++ b/test/ruby/test_io.rb
@@ -2429,8 +2429,8 @@ End
   def test_ioctl_linux2
     return if /linux/ !~ RUBY_PLATFORM
     return if /^i.?86|^x86_64/ !~ RUBY_PLATFORM
-    return unless File.exist?('/dev/tty')
 
+    return unless system('tty', '-s') # stdin is not a terminal
     File.open('/dev/tty') { |f|
       tiocgwinsz=0x5413
       winsize=""