isProcessRunning.js

isProcessRunning.js

//  a signal of 0 can be used to test for the existence of a process. 
var exec = require('child_process').exec
var tryKill

function isRunning(pid, cb) {
  var err = null,
      result = null;
  if (typeof pid !== 'number') {
    err = "pid must be number"
  } else {
    result = tryKill(pid)
  }

  if (err) {
    return err
  }
  return result
}

function tryKillfunction(pid) {
  var result
  try {
    result = process.kill(pid,0)
    return result
  } catch (e) {
    return e.code === 'EPERM';
  }
}