Programming Ruby 3.3

Logger

Ruby has a Logger class that’s accessible with require "logger". It writes log messages to a file or stream and supports automatic time- or size-based rolling of log files. Messages can be assigned severities, and only those messages at or above the logger’s current reporting level will be logged.

A new logger is created with Logger.new(location, shift_age = 0, shift_size = 1048576, **options).

The location is one of the following:

• A string, which is interpreted as a filename; log entries are appended to the file.

• An IO stream, in which case log entries are written to the stream. The stream can be an open File object or any of Ruby’s global streams, like $stdout, but any stream will work.

• nil (or File::NULL), in which case log entries ...