A Groovy library that can be used in a Jenkinsfile to call a shell command and retrieve the output from it.

ShellStepWithOutput.groovy

import java.util.UUID

def command(command) {
    def uuid = UUID.randomUUID()
    def filename = "cmd-${uuid}"
    echo(filename)
    def cmd = "${command} > ${filename}"
    isUnix()?sh(cmd):bat(cmd)
    def result = readFile(filename).trim()
    isUnix()?sh("rm ${filename}"):bat("del ${filename}")
    return result
}

Add compatibility with Windows