From: Christian von Mueffling <cvm@...>
Date: 2003-03-07T01:55:25+09:00
Subject: Re: system command expansion after PTY.spawn

On Fri, Mar 07, 2003 at 12:18:20AM +0900, Yukihiro Matsumoto wrote:

> |require 'pty'
> |pty_read, pty_write, pid = PTY.spawn( "irb" )
> |`uname`
> 
> This works with 1.8.

But i get still strange things here:

-----------------------<snip>-----------------------
require 'pty'
require 'expect'

i, o, pid = PTY.spawn( "irb" )
p pid
puts i.expect( "irb(main):001:0> " )
o.print( "exit\n" )
i.close
o.close

i, o, pid = PTY.spawn( "irb" )
p pid
puts i.expect( "irb(main):001:0> " )
o.print( "exit\n" )
i.close
o.close
-----------------------<snip>-----------------------


This results with ruby 1.8.0 in:
-----------------------<snip>-----------------------
11301
irb(main):001:0> 
11303
t.rb:4:in `expect': pty - exit: 11301 (PTY::ChildExited)
	from t.rb:13
-----------------------<snip>-----------------------


and with ruby 1.6.8 in:
-----------------------<snip>-----------------------
11323
irb(main):001:0> 
11324
/users/cvm/local/gnu/ruby-1.6.8/lib/ruby/1.6/expect.rb:13:in `select': Child_changed: 11323 (RuntimeError)
	from /users/cvm/local/gnu/ruby-1.6.8/lib/ruby/1.6/expect.rb:13:in `expect'
	from t.rb:13
-----------------------<snip>-----------------------

It works if i don't comment out the last 3 lines of each block (but
thenthe processes then are alive until the script ends :-().

Do I use this in a wrong way?

-- 
chris