Module: SilentStream::Extracted

Defined in:
lib/silent_stream.rb

Overview

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

Constant Summary collapse

SILENT_STREAM_NULL_DEVICE = 
defined?(IO::NULL) ? IO::NULL : Gem.win_platform? ? 'NUL:' : '/dev/null'

Instance Method Summary collapse

Instance Method Details

#capture(stream) ⇒ Object

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.



109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
 
# 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 ⇒ Object

Silences both STDOUT and STDERR, even for subprocesses.

quietly { system 'bundle install' }

This method is not thread-safe.



134
135
136
137
138
139
140
 
# File 'lib/silent_stream.rb', line 134

def quietly
  silence_stream(STDOUT) do
    silence_stream(STDERR) do
      yield
    end
  end
end

#silence_stderr ⇒ Object

This method is not thread-safe.



65
66
67
 
# File 'lib/silent_stream.rb', line 65

def silence_stderr
  silence_stream(STDERR) { yield }
end

#silence_stream(stream) ⇒ Object

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.



78
79
80
81
82
83
84
85
86
87
88
89
90
 
# 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