How to return stdout and stderr together with the status from a Jenkins Pipeline sh script step

To return stdout and stderr together with the status you can do the following:

def runScript(command) {
    script {
        sh script: "set +x ; $command 2>&1 && echo \"status:\$?\" || echo \"status:\$?\" ; exit 0", returnStdout: true
    }
}

pipeline {
    agent any

    stages {
        stage('more values from sh') {
            steps {
                script {
                    // inline
                    def stdoutAndStatus = sh script: 'set +x ; ls -a 2>&1 && echo "status:$?" || echo "status:$?" ; exit 0', returnStdout: true
                    echo "stdoutAndStatus: >$stdoutAndStatus<".trim()
                    
                    def stderrAndStatus = sh script: 'set +x ; ls notexisting 2>&1 && echo "status:$?" || echo "status:$?" ; exit 0', returnStdout: true
                    echo "stderrAndStatus: >$stderrAndStatus<".trim()
                    
                    // with function
                    echo "runScript: >${runScript('ls -a')}<".trim()
                    echo "runScript: >${runScript('ls notexisting')}<".trim()
                    
                    // failing the sh step
                    echo "runScript: >${runScript('not_existing_command')}<".trim()
                }
            }
        }
    }
}

Console Output

[Pipeline] stage
[Pipeline] { (more values from sh)
[Pipeline] script
[Pipeline] {
[Pipeline] sh
+ set +x
[Pipeline] echo
stdoutAndStatus: >.
..
status:0
<
[Pipeline] sh
+ set +x
[Pipeline] echo
stderrAndStatus: >ls: notexisting: No such file or directory
status:2
<
[Pipeline] script
[Pipeline] {
[Pipeline] sh
+ set +x
[Pipeline] }
[Pipeline] // script
[Pipeline] echo
runScript: >.
..
status:0
<
[Pipeline] script
[Pipeline] {
[Pipeline] sh
+ set +x
[Pipeline] }
[Pipeline] // script
[Pipeline] echo
runScript: >ls: notexisting: No such file or directory
status:2
<
[Pipeline] script
[Pipeline] {
[Pipeline] sh
+ set +x
[Pipeline] }
[Pipeline] // script
[Pipeline] echo
runScript: >C:/Users/jenkins/AppData/Local/Jenkins/.jenkins/workspace/SO-36956977 more values from sh@tmp/durable-af2cee22/script.sh: line 1: not_existing_command: command not found
status:127
<
[Pipeline] }
[Pipeline] // script
[Pipeline] }
[Pipeline] // stage
[Pipeline] }
[Pipeline] // node
[Pipeline] End of Pipeline
Finished: SUCCESS

In plain (Windows Git) Bash it works as follows (inspired by @Ian W's comment to the question above):

stdErrAndOutAndStatus.sh

stdErrAndOutAndStatus () {
    $1 2>&1 ; echo "status:$?"
}

stdOutAndStatus=$( stdErrAndOutAndStatus 'ls -a' )
echo -e "$stdOutAndStatus\n"
stdErrAndStatus=$( stdErrAndOutAndStatus 'ls notexisting' )
echo -e "$stdErrAndStatus\n"
stdErrAndStatus=$( stdErrAndOutAndStatus 'not_existing_command' )
echo -e "$stdErrAndStatus\n"

Output

$ ./stdErrAndOutAndStatus.sh
.
..
stdErrAndOutAndStatus.sh
status:0

ls: cannot access 'notexisting': No such file or directory
status:2

./stdErrAndOutAndStatus.sh: line 3: not_existing_command: command not found
status:127

NB: I hope there's no pitfall of/in Bash I'm not aware of (yet). I don't write scripts too often.