Ruby:
Writing a text file

How to:

Ruby makes file operations straightforward. To write to a file, you can use Ruby’s built-in File class. The following example demonstrates how to open a file for writing ("w" mode) and append ("a" mode), then write a string to it, and ensure the file is closed afterwards:

# Writing new content to a file, overwriting existing content
File.open("example.txt", "w") do |file|
  file.puts "Hello, Ruby!"
end

# Appending content to the end of a file
File.open("example.txt", "a") do |file|
  file.puts "Adding another line."
end

After running both snippets, the content of example.txt will be:

Hello, Ruby!
Adding another line.

Using a third-party library: FileUtils

For more complex file operations, the Ruby standard library FileUtils can come in handy, though for basic file writing, standard File methods are sufficient. However, if you want to copy, move, remove, or perform other filesystem operations in conjunction with file writing, FileUtils is worth exploring.

An example of using FileUtils for creating a directory and then writing to a file within that directory:

require 'fileutils'

FileUtils.mkdir_p 'logs'
File.open("logs/today.log", "w") do |file|
  file.puts "Log entry: #{Time.now}"
end

This demonstrates creating a new directory logs if it doesn’t already exist, and writing to a new file today.log within it, showcasing both directory and file manipulation without directly writing with FileUtils, but utilizing its directory handling capability.