Logged in user as a Parameter

Summary: How to identify the Logged in user as a Parameter.

Content (required): We would like to store the build details in a file for future reference, even though we can see the details in the build log. We want to maintain a file with Build executor, Input files..etc, instead of searching among the 100's of logs.

How to identify the Build executor name ( person who is running the Job OR Logged in User ) name.

I don't see the parameter to identify the person who is running the build job, but i see the executor name in the the build history under column BY.