From: "Ara.T.Howard" <ahoward@...>
Date: 2004-05-06T06:43:56+09:00
Subject: Re: Reading frin STDIN

On Wed, 5 May 2004, Clayton Wozney wrote:

> I'm using Ruby to create little command line utilities that read from
> STDIN and write to STDOUT so that I can string them together with pipes.
> The I/O part looks like this...
> 
> 	# open up STDIN for reading
> 	infile = IO.new(0, "r")
> 
> 	# read from STDIN until EOF
> 	infile.each_line do |line|
> 
> Now, this works fine when I run it from the command line directly (no
> pipe).  However, when I try to use a pipe like this (for example):
> 
> 	c:\>type file.txt | ruby_script.rb
> 
> I get this error message:
> 
> 	The process tried to write to a nonexistent pipe.
> 	ruby_script.rb:23:in `each_line': Bad file descriptor (Errno::EBADF)
>         from ruby_script.rb:23
> 
> Is there another way to achieve this effect?  Thanx.
> 
> Clayton.

perhaps something like


  unless STDIN.tty?  # we are in a pipeline
    while((line = STDIN.gets))
      p line
    end
  else
  end

however - you error is in __writing__ where are you writing to?

why open up infile - why not simply use STDIN?

-a
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