Ruby Is a Better Perl (Fight Me)

2026-02-22

You've been lied to. Every Ruby tutorial starts with classes, objects, Rails scaffolding, and a mountain of ceremony that has nothing to do with getting actual work done. Here's the truth: Matz built Ruby as a better Perl. The command-line DNA is still there, hiding under years of web framework marketing. Time to dig it out.

Part 1: The Minimal Ruby Manifesto

Inspired by Tim Maher's "Minimal Perl: For UNIX and Linux People," the idea is simple. You don't need to learn all of Ruby to get real work done. Accomplish 90% of tasks with maybe 10% of the language.

Here's your entire toolkit for practical text processing:

Hashes for counting and grouping
Regex for matching and extraction
ARGF for input (like Perl's diamond operator)
puts for output
Command-line switches (-n, -p, -e, -a, -F)

That's it. No classes, no modules, no complexity.

Part 2: What Matz Actually Intended

Ruby was designed by Yukihiro "Matz" Matsumoto as "a better Perl" before Rails hijacked the narrative. The command-line DNA is still there:

All of Perl's favorite switches work
Special variables behave the same way
ARGF is actually more powerful than the diamond operator
The regex engine is comparable
Shell integration is excellent
Quote-like operators (%q, %Q, %r, %w, %x) mirror Perl's q, qq, qr, qw, qx

Part 3: What to Focus On

Command-line switches and special variables
Regular expressions and text manipulation
One-liners for text processing and log parsing
Shell integration and pipeline construction
File operations and in-place editing
Running system commands
Parsing structured data (logs, configs, CSV, JSON)
Building filters that work with Unix tools

Part 4: What to Skip (Seriously, Skip It)

Object-oriented programming (classes, modules, inheritance)
Rails or any web framework
Metaprogramming and eigenclasses
Gems unless directly relevant to text processing
Design patterns from the Rails world
Testing frameworks
Blocks as closures (use blocks for iteration only)

You don't need any of that to parse a log file at 3 AM.

Part 5: The Minimal Ruby Way

#!/usr/bin/env ruby

# Find failed SSH logins - the Minimal Ruby approach
# Run like grep: ruby failed_ssh.rb /var/log/auth.log

# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Track failed login attempts by IP
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

failed = Hash.new(0)  # Hash with default value 0 for counting

ARGF.each_line do |line|
  if line =~ %r~Failed password.*from\s+(\d+\.\d+\.\d+\.\d+)~
    failed[$1] += 1  # $1 holds the captured IP
  end
end

# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Report sorted by count (descending)
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

failed.sort_by { |ip, count| -count }.each do |ip, count|
  printf "%6d  %s\n", count, ip
end

Run it like you'd run grep: ruby failed_ssh.rb /var/log/auth.log. No gems, no Gemfile, no bundle install. Just Ruby doing what Ruby was born to do.