From: "Ara.T.Howard" <Ara.T.Howard@...>
Date: 2005-09-14T00:11:33+09:00
Subject: Re: reopening stdin

On Tue, 13 Sep 2005, Sea&Gull wrote:

> Hi!
>
> I have a script.rb which reads some data from stdin.  Something like this:
>
> bash$ cat file_name | script.rb
>
> In script.rb I have:
>
> #--------------------
> fi = $stdin
>
> fi.each_line do |l|
> 	#...
> end
>
> --------------------
>
> After that script.rb needs to communicate with a user interactively: ask
> what to do and read the answer from... stdin. Something like:
>
> #-------------------
>
> print "\nYes/No: "
> answer = $stdin.gets
>
> #-------------------
>
> Here I had a problem - I can't read user's answer.  I guess I need somehow
> to reopen stdin before calling $stdin.gets but have not found how to do it
> correctly.
>
> Could you please give me a hint?


well, here you setup stdin of the script.rb to be a pipe and therefore it has
no controlling terminal:

   bash$ cat file_name | script.rb

so, even if you reopen it it will still be a pipe - you cannot get back at the
terminal.  i think what you are saying is that you want to open the console
after reading stdin.  so maybe:

   harp:~ > cat a.rb
   print STDIN.read
   STDIN.reopen '/dev/tty'
   print STDIN.read

   harp:~ > printf "42\n" | ruby a.rb
   42
   then i type 42 followed by ctrl-d
   then i type 42 followed by ctrl-d

hth.

-a
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