如何在Jenkins pipeline中获取shell命令得返回

//获取标准输出
//第一种
result = sh returnStdout: true ,script: "<shell command>"
result = result.trim()
//第二种
result = sh(script: "<shell command>", returnStdout: true).trim()
//第三种
sh "<shell command> > commandResult"
result = readFile('commandResult').trim()

//获取执行状态
//第一种
result = sh returnStatus: true ,script: "<shell command>"
result = result.trim()
//第二种
result = sh(script: "<shell command>", returnStatus: true).trim()
//第三种
sh '<shell command>; echo $? > status'
def r = readFile('status').trim()

//无需返回值，仅执行shell命令
//最简单的方式
sh '<shell command>'