在groovy jenkins pipline中跨多个sh调用保持shell

pipeline {
    agent any
    stages {
        stage('Set Environment') {
            steps {
                withEnv(["MY_VAR=my_value"]) {
                    sh 'echo $MY_VAR'
                }
            }
        }
        stage('Use Environment') {
            steps {
                sh 'echo $MY_VAR'
            }
        }
    }
}

pipeline {
    agent any
    stages {
        stage('Multiple Commands in One Shell') {
            steps {
                script {
                    sh '''
                        export MY_VAR=my_value
                        echo $MY_VAR
                        # 其他命令
                    '''
                }
            }
        }
    }
}

pipeline {
    agent any
    stages {
        stage('Write to File') {
            steps {
                sh 'echo "my_value" > my_var.txt'
            }
        }
        stage('Read from File') {
            steps {
                script {
                    def myVar = sh(script: 'cat my_var.txt', returnStdout: true).trim()
                    echo "MY_VAR is ${myVar}"
                }
            }
        }
    }
}