How do I temporarily redirect stderr in Ruby?

Question

I\'d like to temporarily redirect stderr in a Ruby script for the duration of a block, ensuring that I reset it to its original value at the end of the block.

I had

Answer 1

Here is a more abstract solution (credit goes to David Heinemeier Hansson):

def silence_streams(*streams)
  on_hold = streams.collect { |stream| stream.dup }
  streams.each do |stream|
    stream.reopen(RUBY_PLATFORM =~ /mswin/ ? 'NUL:' : '/dev/null')
    stream.sync = true
  end
  yield
ensure
  streams.each_with_index do |stream, i|
    stream.reopen(on_hold[i])
  end
end

Usage:

silence_streams(STDERR) { do_something }