When using the Input step of the workflow, the run pauses until a user proceeds/aborts. There should be a log indicating which user proceeded/aborted.

I think this functionality would be best in InputStepExecution.doSubmit(StaplerRequest request), but I'm not sure, nor am I sure if the request object will have the user info.

sample workflow:

try {
    input "who will be clicking?"
    echo 'echo: who proceeded?'
} catch (e) {
    echo "echo: who aborted it? "
}

sample of desired output: note: Proceed by user Knurek

Started by user Knurek
Running: Input
who will be clicking?
Proceed or Abort
Proceed by user Knurek
Running: Print Message
echo: who proceeded?
Running: End of Workflow
Finished: SUCCESS