From: Dave Burt <dave@...>
Date: 2006-06-08T10:44:10+09:00
Subject: Re: pausing until a character is received

On 6/8/06, Logan Capaldo <logancapaldo@gmail.com> wrote:
>
> On Jun 7, 2006, at 2:17 AM, Dave Burt wrote:
>
> > Logan Capaldo wrote:
> >> What ^C is actually depends on your terminal. If ^C is SIGINT for the
> >> terminal, you'll never get ^C in the input stream no matter what
> >> you do.
> >
> > Not true - if you handle the SIGINT, there's no reason why you
> > shouldn't get a character in the input stream. Here's an irb session
> > ...
>
> Aha. Well I think our respective operating systems have a difference
> of opinion here. Try it on a *NIX. (Note that with a unix terminal
> you could have SIGINT be ^P if you wanted).
>
> ^A (the character) will go through but ^C will not because it is
> handled by the terminal, and the terminal simply does a kill(SIGINT)
> on the process, it doesn't write to the processes stdin.

Interesting. I'm sorry for my blunt denial; I actually even expected
this might be the case.

So in that case Sy would have to explicitly write it into the input
stream if he wanted to get it out, although if he only wants to "pause
until a character is received," there's no need.

Something like the following (un-tested)

begin
  require "Win32API"
  def read_char
    Win32API.new("crtdll", "_getch", [], "L").Call
  end
rescue LoadError
  def read_char
    system "stty raw -echo"
    STDIN.getc
  ensure
    system "stty -raw echo"
  end
end

trap :INT &begin
  require 'termios'  # http://raa.ruby-lang.org/project/ruby-termios/
  c = Termios.tcgetattr(STDIN).cc[Termios::VINTR]
  proc { STDIN << c }
rescue LoadError
  proc {}
end

Does that work?

Cheers,
Dave