From: Gavin Sinclair <gsinclair@...>
Date: 2002-08-16T16:24:04+09:00
Subject: Re: For Windows users only...

Having bluntly stated my solution, let me elaborate by example.  Below is
a complete Cygwin transcript demonstrating: (a) running Ruby programs; (b)
redirecting standard output; (c) redirecting standard error; (d) fortune.

Before I get into it, can I ask a question?  Am I missing out on anything
by not using the "native" windows installation?

Transacript follows after signoff.

Cheers,
Gavin


   The steady state of disks is full.
                   -- Ken Thompson
   ----

   Next three birthdays:
     John Brondum    2002-09-18      (in 33 days)
     David Wells     2002-09-21      (in 36 days)
     Ian Morris      2002-09-30      (in 45 days)

   Gavin Sinclair@NOSEDOG ~
   $ cd /tmp

   Gavin Sinclair@NOSEDOG /tmp
   $ cat > demo.rb
   #!/usr/local/bin/ruby

   puts <<EOF
   I'm a little vegemite
   As bright as bright can be
   We all enjoy our vegemite
   For breakfast, lunch and tea
   EOF

   Gavin Sinclair@NOSEDOG /tmp
A  $ ./demo.rb
   I'm a little vegemite
   As bright as bright can be
   We all enjoy our vegemite
   For breakfast, lunch and tea

   Gavin Sinclair@NOSEDOG /tmp
B  $ ./demo.rb > output

   Gavin Sinclair@NOSEDOG /tmp
   $ cat output
   I'm a little vegemite
   As bright as bright can be
   We all enjoy our vegemite
   For breakfast, lunch and tea

   Gavin Sinclair@NOSEDOG /tmp
   $ cat > err.rb
   #!/usr/local/bin/ruby

   STDERR.puts "I'm nasty"
   STDOUT.puts "I'm nice"

   Gavin Sinclair@NOSEDOG /tmp
   $ ./err.rb
   I'm nasty
   I'm nice

   Gavin Sinclair@NOSEDOG /tmp
B  $ ./err.rb > /dev/null
   I'm nasty

   Gavin Sinclair@NOSEDOG /tmp
C  $ ./err.rb 2> /dev/null
   I'm nice

D  Gavin Sinclair@NOSEDOG /tmp
   $ fortune -o
   The problem with being best man at a wedding is
   that you never get a chance to prove it.

   Gavin Sinclair@NOSEDOG /tmp
   $


> At the command line, that is.
>
> Problem: When you run a .rb file from the
> command line, you have to type a (potentially
> lengthy) command.
>
> First idea: Wrap it in a batch file.
>
> However: Did you know that Windows is too dumb
> to associate the stdout of a program with the
> stdout of the batch file? I.e., if you have a
> foo.bat file and you say "foo >outfile" it will
> NOT work (at least not in older Windows versions...
> I can't speak of NT, 2K, XP).
>
> Well, you can use "start" on Win98. Still kind of
> a pain.
>
> My solution:
>
> Write a C program that will detect its own name and
> directory; locate a corresponding Ruby program in
> that same directory; read the #! line from the
> beginning (usu. ignored in Win); and run the Ruby
> program. It passes in the parameters, too.
>
> Note that you only have to compile once, since the
> program knows its own name. You can just
>   copy fakeruby.exe myprog.exe
> assuming there is a myprog.rb in that directory.
>
> I know, it's kind of an exercise in futility. But
> if you want the code, here it is. It compiles fine
> with djgpp.
>
> Feel free to criticize it or improve it. It's far
> from perfect. For some reason, execvp() didn't work
> for me.
>
> Cheers,
> Hal
>
> [lovely-looking C code snipped]