Calling an external command (useful for build scripts)

run.rb

def run(command, abort_on_failure = true)
  command.strip!

  puts "> #{command}" if !block_given?
  IO.popen("#{command} 2>&1") do |proc|
    while !proc.closed? && (line = proc.gets)
      if block_given?
        yield line
      else
        puts ">    #{line}"
      end
    end
  end

  if $?.exitstatus != 0
    msg = "Operation exited with status #{$?.exitstatus}"
    raise msg if abort_on_failure
  end

  return $?
end