Full paths of Ruby interpreter and running script


I’ve looked through and experimented with predefined global constants,
but so far have not figured how to get the full path and name of the
Ruby interpreter and/or main script file from within a running program.
I want to distribute a program that can be installed in a folder chosen
by the user. The program would save configuration information in the
same folder. In order to find the configuration file at runtime, I
thought I would query the full path of the Ruby interpreter or script
file. In case it makes a difference, I’m using Windows.