Ruby places any parameters that are appended to the command line when you launch your Ruby program into a special array called ARGV.
To test it out, create a new script called argv.rb and use this code:
From the command prompt, run the script like so:
The result will be blank, but then try to run it like so:
ruby argv.rb test 123
Here, the parameters are taken from ARGV, joined together with a hyphen, and displayed on the screen.