Jenkinsfile: How to get the author name for the HEAD commit

jenkinsfile.txt

AUTHOR_NAME = bat (
      script: "git show -s --format='%%an' HEAD",
      returnStdout: true
  ).split('\r\n')[2].trim()

echo "The last commit was written by ${AUTHOR_NAME}."
echo "PS - Jenkins sucks giant monkey balls."

Patch: Use a single % instead of two.

> git show --help | grep 'author name'
           ·   %an: author name
           ·   %aN: author name (respecting .mailmap, see git-shortlog(1) or git-blame(1))

Patch: Use a single % instead of two.

You need the double % in the Jenkinsfile which is a groovy script.