DeferrableChildProcess

deferrable_child_process.rb

require 'eventmachine'

# Code adapted from EM's tests:
# https://github.com/eventmachine/eventmachine/blob/master/tests/test_processes.rb#L43

ls = ""
EM.run {
  d = EM::DeferrableChildProcess.open( "ruby -v" )
  d.callback {|data_from_child|
    ls = data_from_child
    EM.stop
  }
}

puts ls

# linux
# $ ruby -Ilib test_processes.rb 
# ruby 1.9.2p0 (2010-08-18 revision 29036) [x86_64-linux]

# winxp
# >ruby -Ilib test_processes.rb
# terminate called after throwing an instance of 'std::runtime_error'
#   what():  socketpair is currently unavailable on this platform
#
# This application has requested the Runtime to terminate it in an unusual way.
# Please contact the application's support team for more information.