Single file Ruby scripts — Łukasz Adamczak

Running some Python scripts with uv, I came across its support for declaring script dependencies in the Python file itself:

# /// script
# dependencies = [
#   "requests<3",
#   "rich",
# ]
# ///

import requests
from rich.pretty import pprint

resp = requests.get("https://peps.python.org/api/peps.json")
data = resp.json()
pprint([(k, v["title"]) for k, v in data.items()][:10])

I figured something like this should be possible in Ruby. And indeed it is!

As long as you have Bundler, you can write self-contained Ruby scripts - with dependencies - using bundler/inline.

My favourite use is quick scrapers with Nokogiri:

require 'bundler/inline'
require 'open-uri'

gemfile do
  source 'https://rubygems.org'
  gem 'nokogiri'
end

doc = Nokogiri::HTML(URI.open('https://czak.pl/til/single-file-ruby-scripts'))

puts doc.title