From: matz@... (Yukihiro Matsumoto)
Date: 2003-03-07T02:46:17+09:00
Subject: Re: system command expansion after PTY.spawn

Hi,

In message "Re: system command expansion after PTY.spawn"
    on 03/03/07, Christian von Mueffling <cvm@aiss.de> writes:

|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>-----------------------

I think it's the original design by A.Ito, the author of pty.
You have to protect PTY.spawn like:

  begin
    PTY.spawn( "irb" ) do |i,o,pid|
      p pid
      puts i.expect( "irb(main):001:0> " )
      o.print( "exit\n" )
      i.close
      o.close
    end
  rescue
    p $!
  end

If you want to know the reason of this design, you have to ask him.
I think he still can be reached at the address in the ext/pty/README,
although I haven't seen him around for a while.

							matz.