Just run it with no argument:
ruby entry.rb
I confirmed the following implementations/platforms:
- ruby 2.2.3p173 (2015-08-18 revision 51636) [x86_64-linux]
- ruby 2.1.7p400 (2015-08-18 revision 51632) [x86_64-linux]
- ruby 2.0.0p645 (2015-08-18 revision 51630) [x86_64-linux]
This is the real meta programming.
I don't want to write long code, then I compressed the code a little.
None