Paths and Utils in Ruby

Work with file system paths using Pathname, __FILE__, __dir__, and utility modules in Ruby.

Path Constants & Magic Variables

Ruby provides two magic constants for the current file's location: `__FILE__` returns the current file's path, and `__dir__` returns the directory containing it. These are resolved at load time — essential for building paths that work no matter where your script is run from.

1. __FILE__ and __dir__

The foundation of reliable relative paths in Ruby.

2. $LOAD_PATH & require_relative

Control where Ruby looks for required files.

File Class — Path Operations

Ruby's `File` class has a comprehensive set of class methods for path manipulation — no separate path module needed. All methods work cross-platform (Unix `/` and Windows `\`).

1. File.join & File.expand_path

Build and resolve paths safely.

2. Parsing Path Components

Extract basename, dirname, extension, and filename without extension.

3. File Predicates — Existence & Type Checks

Check if a path exists, is a file, directory, or symlink.

Pathname — Object-Oriented Paths

`Pathname` wraps a path string in an object with methods for every `File` and `Dir` operation. It makes complex path operations readable through method chaining instead of nested `File.` calls.

1. Pathname Basics

Create and navigate paths with Pathname.

2. File System Operations with Pathname

Read, write, glob, and iterate with Pathname.

Useful Ruby Utility Methods

Ruby's standard library includes utility modules and methods that every Ruby developer should know — for debugging, benchmarking, deep comparison, and object introspection.

1. pp & inspect — Variable Inspection

Pretty-print any object for debugging.

2. Deep Comparison & Object Identity

== vs eql? vs equal? — know the difference.

3. Benchmark — Measuring Performance

Time code blocks with the standard Benchmark module.

4. ObjectSpace — Runtime Object Introspection

Count live objects and find all instances of a class.