Comma delimited files are still used for importing and exporting of data. The Ruby Standard Library includes a class for manipulating them. When a file is read each row is converted to an array with each element of the array being a string. Files are created by writing out arrays. Following is a marketing email example.
File of people to send an email to.
John,Doe,john@commonthread.com Peter,Rabbit,peter@commonthread.com Billy,Goat,billy@commonthread.com
Creating the file.
require 'csv' csv...
