testing command execution ideas

gistfile1.rb

require 'open3'
require 'pp'
require 'eventr'
require 'stringio'

$eventr = Eventr::Coordinator.instance
$eventr.publishers(:stderr, :stdout)
$eventr.consumer(:stderr) { |msg| $stderr.puts "STDERR: #{msg}" }
$eventr.consumer(:stdout) { |msg| $stdout.puts "STDOUT: #{msg}" }
$eventr.start

ENV_WHITELIST = %w( PATH HOME LDFLAGS CPPFLAGS DISPLAY EDITOR LANG LC_ALL SHELL SHLVL TERM TMPDIR USER )

def prep_env(env = nil)
  env ||= Hash[ENV]
  Hash[env].inject([]) { |array,(k,v)|
    array << "#{k}=#{v}" if ENV_WHITELIST.include? k
    array
  }
end

def command(*args)
  env_arr = prep_env(Hash[ENV])

  cmd = args.join(' ')
  puts "Command: #{cmd}"

  result = Open3.popen3('/usr/bin/env', '-i', *env_arr, 'bash', '-c', cmd) do |i, out, err, thr|
    o = Thread.new do
      output = StringIO.new
      loop {
        begin
          output << _o = out.readpartial(4096)
          $eventr.publish(:stdout, _o)
        rescue EOFError
          break
        end
      }
      output.rewind
      output.read
    end

    e = Thread.new do
      error = StringIO.new
      loop {
        begin
          error << _e = err.readpartial(4096)
          $eventr.publish(:stderr, _e)
        rescue EOFError
          break;
        end
      }
      error.rewind
      error.read
    end

    sleep 1 while thr.alive?

    [ o.value, e.value, thr.value ]
  end
end

pp command('sleep 3; echo foo; sleep 2; echo 2; sleep 1; echo bar')