README.md

stdouterr.rb

A script designed to stress SSHKit by outputting on stdout and stderr with and without buffering, with and without flushing it's outputs to try and find a reliable solution for capturing outputs from programs which are badly behaved.

Example Usage

$ ruby ./stdouterr.rb --unbuffered --succeed
0. Lorem ipsum dolor sit amet, consectetur adipiscing elit.
0. Proin nec tristique nisl.
1. Pellentesque venenatis magna malesuada aliquam posuere.
2. Ut interdum ornare massa.
1. Suspendisse ultrices, mauris vitae lobortis tempus, ipsum mi facilisis purus, vel auctor purus nisl sit amet eros.
2. Aliquam nec varius ante.
succeeding

Available Options

 --buffered / --unbuffered   Sync stdout and stderr?
 --fail / --succeed          Exit with `1' or `0'
 --flush                     In case of --buffered, flush every line after writing?

stdouterr.rb

require 'getoptlong'

output = [
  'Lorem ipsum dolor sit amet, consectetur adipiscing elit.',
  'Pellentesque venenatis magna malesuada aliquam posuere.',
  'Ut interdum ornare massa.',
  'Proin nec tristique nisl.',
  'Suspendisse ultrices, mauris vitae lobortis tempus, ipsum mi facilisis purus, vel auctor purus nisl sit amet eros.',
  'Aliquam nec varius ante.'
]

opts = GetoptLong.new(
  [ '--buffered',   '-b', GetoptLong::NO_ARGUMENT ],
  [ '--unbuffered', '-u', GetoptLong::NO_ARGUMENT ],
  [ '--fail',       '-f', GetoptLong::NO_ARGUMENT ],
  [ '--succeed',    '-s', GetoptLong::NO_ARGUMENT ],
  [ '--flush',      '-l', GetoptLong::NO_ARGUMENT ]
)

mode = nil
code = nil
flush = nil

opts.each do |opt|
  case opt
  when '--buffered'   then mode = :buffered
  when '--unbuffered' then mode = :unbuffered
  when '--fail'       then code = 1
  when '--succeed'    then code = 0
  when '--flush'      then flush = true
  end
end

unless mode
  abort "Must specify one of --buffered or --unbuffered"
end

unless code
  abort "Must specify one of --fail or --succeed"
end

if mode == :unbuffered and flush == true
  abort "--flush (-l) only has meaning to buffered outputs"
end

if mode == :unbuffered
  $stdout.sync = false
  $stderr.sync = false
end

stdout_t = Thread.new do
  output[0..2].each_with_index do |line, i|
    $stdout.write "%d. %s\n" % [i, line]
    $stdout.flush if flush
  end
end

stderr_t = Thread.new do
  output[3..5].each_with_index do |line, i|
    $stderr.write "%d. %s\n" % [i, line]
    $stderr.flush if flush
  end
end

[stdout_t, stderr_t].map(&:join)

if code == 1
  abort("failing")
else
  puts("succeeding")
end