exports.killByPort = function (port) {
  var processId = null
  try {
    processId = exec(`lsof -t -i:${port}`)
  } catch (e) {

  }

  if (processId !== null) { // if exists kill
    exec(`kill ${processId}`)
  }
}
The software constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.