How do I pass variables between stages in a declarative Jenkins pipeline? : <p>How do I pass variables between stages in a declarative pipeline?</p>

<p>In a scripted pipeline, I gather the procedure is to write to a temporary file, then read the file into a variable.</p>

<p>How do I do this in a declarative pipeline?</p>

<p>E.g. I want to trigger a build of a different job, based on a variable created by a shell action.</p>

<pre><code>stage("stage 1") {
    steps {
        sh "do_something &gt; var.txt"
        // I want to get var.txt into VAR
    }
}
stage("stage 2") {
    steps {
        build job: "job2", parameters[string(name: "var", value: "${VAR})]
    }
}
</code></pre>
