Losing STDOUT when using Open3.capture3 and rake?

Question

A build system that I use at work invokes several external console applications, Node.js among others.

The issue I am seeing is the STDOUT channel seems to not work after Open3.capture3 is invoked. For instance, I have a task called compileLess:

desc "Compile LESS"
task :compileLess do
   puts "Preparing to compile LESS..."
   execute "recess less/bootstrap.less --compress > output/css/bootstrap.min.css"
   puts "Finished compiling LESS"
end


def execute(cmdLine, print_stdout = false)
   puts "Executing #{cmdLine}"
   stdout, stderr, status = Open3.capture3(cmdLine)
   puts stdout if print_stdout
   return stdout, stderr, status
end

What I would expect to see is something like:

Preparing to compile LESS...
Executing recess less/bootstrap.less --compress > output/css/bootstrap.min.css
Finished compiling LESS

But anything after the invocation of Open3.capture3 disables puts and print. I can force them to work by explicitly using:

STDOUT.puts "goodbye world"

I just want to know why it doesn't work.

Specs:

Window 7 Professional 32 bit
Ruby 1.9.3p392 (2013-02-22) [i386-mingw32]
Rake, version 10.1.0
Node v0.10.22

I mentioned what I get in the question, but to reiterate, any puts or prints after the open3 capture doesn't print anything to the console. — MattSaw, Nov 14 '13 at 10:43

score 1 · Answer 1 · edited Dec 02 '13 at 18:29

1

You redirected the STDOUT of the command-line with > output/css/bootstrap.min.css.

Your STDOUT from capture3() is empty of course.

edited Dec 02 '13 at 18:29

the Tin Man

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answered Nov 13 '13 at 20:22

jaeheung

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Any suggestion as to how I can write the css to disk without losing STDOUT? – MattSaw Nov 14 '13 at 10:45
1

@MattSaw How about " | tee output/css/bootstrap.min.css" instead of " > output/css/bootstrap.min.css"? Not sure if it's what you wanted. – jaeheung Nov 14 '13 at 19:11

Losing STDOUT when using Open3.capture3 and rake?

1 Answers1