From: Mark Hubbart <discord@...>
Date: 2004-05-06T06:23:47+09:00
Subject: Re: Reading frin STDIN


On May 5, 2004, at 1:48 PM, 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.

Not sure why your way wouldn't work, but: any particular reason you 
aren't using STDIN and STDOUT?

   STDIN.each_line do |line|
     # do stuff with line
     STDOUT.write line
   end

cheers,
--Mark