Based on Magnus' answer but as a simple oneliner with still readable output:

com.cloudbees.plugins.credentials.SystemCredentialsProvider.getInstance().getCredentials().forEach{println it.dump().replace(' ', '\n')}

Based on Magnus' answer but as a simple one-liner with still readable output:

com.cloudbees.plugins.credentials.SystemCredentialsProvider.getInstance().getCredentials().forEach{println it.dump().replace(' ', '\n')}