Overview

It is possible to run a ruby code directly on a command line or the terminal itself.  We need to pass the -e flag. This is the syntax for the same

ruby -e "<ruby_code>"

Program

Below is one simple example

ruby -e "puts 'hello'"

Run the above command on the terminal and it will give the output

hello

How to run the multiline ruby code. Below is an example of the same. You don’t need to use -e flag.

ruby <<END
 puts "Start"
 5.times do |i|
   puts i
 end
 puts "End"
END

The above program will output

Start
0
1
2
3
4
End