Restart children if they die

restart_children.rb

#!/usr/bin/env ruby

@jobs = [
  "sleep 1",
  "sleep 2",
  "sleep 3",
  "sleep 4"
]

@running_jobs = Hash.new


trap("CLD") do
  begin
    cpid = nil
    cpid = Process.wait
    job =  @running_jobs[cpid]
    puts "Child died #{cpid}: #{job}"
    @running_jobs.delete cpid
    fork_job job
  rescue Errno::ECHILD
    puts "Got Errno::ECHILD"
  rescue Exception => e
    puts e.message
  end
end

def start
  @jobs.each do |job|
    fork_job job
  end
end

def fork_job(job = nil)
  if pid = Process.fork # parent
    @running_jobs[pid] = job
  else # child
    puts "starting #{job}"
    Process.exec job
  end
  status
end


def status
  @running_jobs.each_pair do |pid, job|
    puts "Running #{pid}: #{job}"
  end
end

start

sleep