Accessing Variables Specified for Jenkins Groovy Plugin Script

Question

When writing a script that is run by Jenkins Groovy Plugin as a build step (Execute System Groovy Script) one can specify 'variable bindings'. The helpline says: Define varibale bingings (in the properties file format). Spefified variables can be addressed from the script. [sic] How do I access those variables from the script? They are not set as environment variables for the build, neither are they present among System properties.

Answer 1

this.getBinding().getVariables()

or simply binding.variables

Answer 2

I wasn't able to use binding.variables directly, I only got listener, build, launcher and out from binding.variables.

Instead I was able to use build.environment(listener) to retrieve the environment variables as suggested in the responses to this question: Access to build environment variables from a groovy script in a Jenkins build step ( Windows)

def config = new HashMap()
config.putAll(binding.variables)
def logger = config['out']
def envvars = new HashMap()
envvars.putAll(build.getEnvironment(listener))
def myvar= envvars['myvar']

This might have been different for me since I am only looking for system-wide environmental variables:

(checked) Prepare an environment for the run \ Keep Jenkins Environment Variables \ Keep Jenkins Build Variables