From: Ryan Leavengood <leavengood@...>
Date: 2006-05-07T14:24:58+09:00
Subject: Re: Output redirection in windows

It works for me on the latest One-Click:

C:\_Ryan\downloads>irb
irb(main):001:0> system('echo "hello world!" > hello.txt')
=> true
irb(main):002:0> exit

C:\_Ryan\downloads>type hello.txt
"hello world!"

Another option is to do the redirection yourself:

 File.open('output.txt', 'w') do |file|
   IO.popen('dir') do |pipe|
     pipe.each do |line|
       file.print line
     end
   end
 end

Ryan

On 5/7/06, Aditya Mahajan <adityam@umich.edu> wrote:
> I am using the one-click installer on windows (RC2). I can not get
> output redirection to work with Kernel.system. Consider the following code
>
> F:\tmp\cont-test\test>cat test.rb
> def test(command)
>    puts command
>    puts Kernel.system(command)
>    puts "---------------------------"
> end
>
> test("mpto mp-test-01.mp")
> test("mpto mp-test-01.mp > mp-test-01-test.tex")
>
>
> mpto.exe is a helper program that comes with metapost and is part of most tex
> distributions. It is included in my path environment. I have a file
> mp-test-01.mp in the current directory. mpto scans the .mp file and outputs on
> stdout. I want to redirect that output to a file. But > does not work.
>
> Running this program gives
>
> F:\tmp\cont-test\test>ruby test.rb
> mpto mp-test-01.mp
> \gdef\mpxshipout{\shipout\hbox\bgroup
>    \setbox0=\hbox\bgroup}
> \gdef\stopmpxshipout{\egroup  \dimen0=\ht0 \advance\dimen0\dp0
>    \dimen1=\ht0 \dimen2=\dp0
>    \setbox0=\hbox\bgroup
>      \box0
>      \ifnum\dimen0>0 \vrule width1sp height\dimen1 depth\dimen2
>      \else \vrule width1sp height1sp depth0sp\relax
>      \fi\egroup
>    \ht0=0pt \dp0=0pt \box0 \egroup}
> \mpxshipout% line 2 mp-test-01.mp
> This is a test\stopmpxshipout
> \end{document}
> true
> ---------------------------
> mpto mp-test-01.mp > mp-test-01-test.tex
> false
> ---------------------------
>
> system "mpto ..." executes correctly (the true after \end{document})
> while system "mpto ... > ...." fails. No mp-test-01-test.tex file is created.
>
> When I give the same commands from cmd.exe they work. I am confused why
> something as simple as output redirection is not working. What is the correct
> way to do this?
>
> Thanks,
> Aditya
>
>