From: Brian Candler <B.Candler@...>
Date: 2004-11-02T22:25:51+09:00
Subject: Re: Ruby redirection woes

> You actually need to run the test script with a shell redirection. Like
> in the example output I gave, I redirected output of the script to a
> file, output.txt, and then cat'ed it:
> 
>     $ ruby command_runner_shell_test.rb > output.txt
>     $ cat output.txt

My apologies for not reading your post more carefully. Yes, I get the same
here - and Matz has posted a patch which fixes it in Ruby. (However I'm not
sure that fix is necessarily good; the same problem would happen with other
filehandles which are open, and there's no proposal that fork() should flush
all those too).

However you can also just fix your command_runner.rb like this:

--- command_runner.rb.orig      Tue Nov  2 13:21:01 2004
+++ command_runner.rb   Tue Nov  2 13:21:41 2004
@@ -33,6 +33,8 @@
         child_to_parent_read, child_to_parent_write             = IO.pipe
         child_to_parent_error_read, child_to_parent_error_write = IO.pipe
         
+        $stdout.flush
+        $stderr.flush        
         @childPid = fork do
             parent_to_child_write.close
             child_to_parent_read.close

(The $stderr.flush maybe isn't needed, as I seem to remember that stderr
is unbuffered normally, but it won't do any harm to have it there)

Regards,

Brian.