         # File lib/em/processes.rb, line 108
    108:   def EventMachine::system cmd, *args, &cb
    109:     cb ||= args.pop if args.last.is_a? Proc
    110:     init = args.pop if args.last.is_a? Proc
    111:
    112:     # merge remaining arguments into the command
    113:     cmd = ([cmd] + args.map{|a|a.to_s.dump}).join(' ')
    114:
    115:     EM.get_subprocess_pid(EM.popen(cmd, SystemCmd, cb) do |c|
    116:       init[c] if init
    117:     end.signature)
    118:   end