Programming Ruby 3.3

Processing Command-Line Arguments to Your Code

Just as you can pass arguments to methods in your Ruby code, you can pass arguments from the command line to the Ruby script itself. Ruby provides mechanisms for capturing arguments passed to the script and allowing you to read and parse them as part of your script.

ARGV

Any command-line arguments after the program filename are available to your Ruby program in the global array ARGV. For instance, assume test.rb contains the following program:

ARGV.each { |arg| p arg }

If you invoke it with the following command line:

$ ruby -w test.rb "Hello World" a1 1.6180

It’ll generate the following output:

"Hello World"
"a1"
"1.6180"

There’s a gotcha here for all you C programmers. In Ruby, ...