Temporarily suppress STDOUT and STDERR (ruby)

suppress_ruby_output.rb

# Temporarily redirects STDOUT and STDERR to /dev/null
# but does print exceptions should there occur any.
# Call as:
#   suppress_output { puts 'never printed' }
#
def suppress_output
  original_stderr = $stderr.clone
  original_stdout = $stdout.clone
  $stderr.reopen(File.new('/dev/null', 'w'))
  $stdout.reopen(File.new('/dev/null', 'w'))
  yield
ensure
  $stdout.reopen(original_stdout)
  $stderr.reopen(original_stderr)
end

👍 🎉

Nice one guys! Very useful :)

Awesome little ditty.

How can this be edited to instead of just suppressing by sending to dev/null, it instead returned the output so that it can be stored in a variable? Can this be done without redirecting to a file?

@nancy-gomez, for this you might want to use https://docs.ruby-lang.org/en/2.5.0/Open3.html#method-c-popen3

@iamtheiconoclast I realise I never looked at the comments here. 😅 Thanks for your suggested simplifications; I've amended the Gist to reflect them.

Windows Version with File::NULL

# Temporarily redirects STDOUT and STDERR to /dev/null
# but does print exceptions should there occur any.
# Call as:
#   suppress_output { puts 'never printed' }
#
def suppress_output
  original_stderr = $stderr.clone
  original_stdout = $stdout.clone
  $stderr.reopen(File.new(File::NULL, 'w'))
  $stdout.reopen(File.new(File::NULL, 'w'))
  yield
ensure
  $stdout.reopen(original_stdout)
  $stderr.reopen(original_stderr)
end

FYI https://stackoverflow.com/questions/1496019/suppresing-output-to-console-with-ruby/1496040#1496040