From: Jan Svitok <jan.svitok@...>
Date: 2007-03-03T07:28:33+09:00
Subject: Re: Ruby Noob: Using stderr, stdout, etc

On 3/2/07, Rick DeNatale <rick.denatale@gmail.com> wrote:
> On 3/2/07, Jenda Krynicky <jenda@cpan.org> wrote:
> > reed.adam@gmail.com wrote:
> > > Thanks for the explanation Tim, that's exactly what I needed.  I
> > > didn't realize they would act differently under windows/unix - I think
> > > I was stuck on imagining them as code-specific items because I wasn't
> > > used to hearing about them in unix.
> > >
> > > Strangely enough, I'm ok as far as unix and pipe/redirection, and I've
> > > been logging output of standard unix stuff to files for a couple of
> > > years - just never knew specifically what the output was called.  Go
> > > figure.
> >
> > The thing to watch out for under Windows is that (at least on some
> > versions)
> >
> >    script.rb > results.txt
> >
> > doesn't work and you have to write
> >
> >    ruby script.rb > results.txt
> >
> > This is caused by the fact that the cmd.exe has to use a different WIN32
> > API call to execute the script using the file extension mapping than
> > what it would use for .exe and thatthe former doesn't preserve the
> > STDxxx redirection.
>
> Also, although I haven't really kept up with windows, it used to be
> able to redirect stdout, but not stderr.

I was surprised when I learnt that since win2k it's possible to
redirect stderr and even redirect stderr to stdout or vice versa,
using

progname 2> stderr.txt and progname 2&>1

You know, after all those years, maybe we'll be able to call cmd.exe a shell :D

Other useful bits are:

^ is escape char - for escaping |, > etc.
|| and && work in windows as well


So... reading help might be useful and surprising sometimes...