module SilentStream::Extracted

Extracted from: github.com/rails/rails/blob/4-2-stable/activesupport/lib/active_support/core_ext/kernel/reporting.rb

Constants

SILENT_STREAM_NULL_DEVICE
SILENT_STREAM_REGEXP_HAS_MATCH
SILENT_STREAM_WINDOWS_REGEXP

Public Instance Methods

capture(stream) { || ... } click to toggle source

Captures the given stream and returns it:

stream = capture(:stdout) { puts 'notice' }
stream # => "notice\n"

stream = capture(:stderr) { warn 'error' }
stream # => "error\n"

even for subprocesses:

stream = capture(:stdout) { system('echo notice') }
stream # => "notice\n"

stream = capture(:stderr) { system('echo error 1>&2') }
stream # => "error\n"

This method is not thread-safe.

# File lib/silent_stream.rb, line 109
def capture(stream)
  stream = stream.to_s
  captured_stream = Tempfile.new(stream)
  stream_io = eval("$#{stream}")
  origin_stream = stream_io.dup
  stream_io.reopen(captured_stream)

  yield

  stream_io.rewind
  captured_stream.read
ensure
  captured_stream.close
  captured_stream.unlink
  stream_io.reopen(origin_stream)
end
quietly() { || ... } click to toggle source

Silences both STDOUT and STDERR, even for subprocesses.

quietly { system 'bundle install' }

This method is not thread-safe.

# File lib/silent_stream.rb, line 134
def quietly
  silence_stream(STDOUT) do
    silence_stream(STDERR) do
      yield
    end
  end
end
silence_stderr() { || ... } click to toggle source

This method is not thread-safe.

# File lib/silent_stream.rb, line 65
def silence_stderr
  silence_stream(STDERR) { yield }
end
silence_stream(stream) { || ... } click to toggle source

Silences any stream for the duration of the block.

silence_stream(STDOUT) do
  puts 'This will never be seen'
end

puts 'But this will'

This method is not thread-safe.

# File lib/silent_stream.rb, line 78
def silence_stream(stream)
  old_stream = stream.dup
  begin
    stream.reopen(SILENT_STREAM_NULL_DEVICE, 'a+')
  rescue Exception => e
    stream.puts "[SilentStream] Unable to silence. #{e.class}: #{e.message}"
  end
  stream.sync = true
  yield
ensure
  stream.reopen(old_stream)
  old_stream.close
end

Private Instance Methods

windows_os_test() click to toggle source
# File lib/silent_stream.rb, line 146
def windows_os_test
  # When available, in Ruby 2.4+, we use Regexp#match? which does not update
  #   the $~ global object and may be 3x faster than alternative match tests
  if SILENT_STREAM_REGEXP_HAS_MATCH
    SILENT_STREAM_WINDOWS_REGEXP.match?(RbConfig::CONFIG['host_os'])
  else
    SILENT_STREAM_WINDOWS_REGEXP =~ (RbConfig::CONFIG['host_os'])
  end
end