Ruby:
Reading a text file

How to:

Reading a file in Ruby is straightforward. You can use the File class, which provides different methods to read files. Here’s a simple example of reading an entire file:

File.open("example.txt", "r") do |file|
  puts file.read
end

If example.txt contains the text “Hello, Ruby!”, here’s what you’ll get:

Hello, Ruby!

For reading line by line:

File.foreach("example.txt") { |line| puts line }

Same example.txt, now output will be line by line:

Hello, Ruby!

Deep Dive:

Historically, reading files has been a core feature of programming languages, allowing interactions with the filesystem.

In Ruby, you can also read a file with different tools:

1. IO class: For low-level file operations.
2. readlines method: Loads the entire file into an array, with each line as an element.
3. File.read: Quick way to read an entire file into a string.

There’s a trade-off to consider: File.read is neat for small files, but it can be memory intensive for larger ones. That’s when reading line by line or in chunks becomes valuable.

See Also:

• Ruby Docs for the File class: ruby-doc.org/core/File.html
• Stack Overflow discussions on file reading in Ruby: stackoverflow.com/questions/tagged/ruby+file-io