From: Caleb Clausen <vikkous@...>
Date: 2010-04-30T06:24:30+09:00
Subject: Re: Use of STDOUT.flush after puts

On 4/29/10, hemant <gethemant@gmail.com> wrote:
> Ruby standard library uses IO#reopen many places on STDOUT. I am not
> saying since Ruby standard library does that, it has to be best

Not necessarily. There are some dusty corners in stdlib. If stdlib
does this, it may be a bug; can you give examples?

The one place I know of is the cgi library, which reopens
STDIN/OUT/ERR as part of the process of purifying the environment of
the cgi server process. Other servers might do the same and it would
be appropriate there as well.

I guess the other case where it would be necessary is if you want to
change the STDIN/OUT/ERR seen by subprocesses.

In other cases that I know of, modifying STDIN/OUT/ERR is not a good idea....

> How can reopen change the class btw? Ruby is not a class oriented language
> btw.

Check out this code. No other method in all of ruby has this behavior.

  p $stderr.class #=>IO

  f=File.new "foo","w"
  $stderr.reopen(f)

  p $stderr.class #=>File