…bundler can be used without a gemfile.
I didn’t know that up until now, but obviously, you can inline bundler within your ruby scripts. No need to have a dedicated Gemfile or to call bundler before calling your script. Just do:
require 'bundler/inline'
gemfile do
source 'https://rubygems.org'
gem 'rest-client'
end
puts RestClient.get('https://news.ycombinator.com/')
You can see the source on their GitHub repo. This becomes espescially interesting not only for small scripts, but also to have small executable files, that behave like a regular executable.
A small example
Image being able to do this from your command line:
$ weather berlin
Today it is -2.51°C in Berlin with few clouds.
Easily done:
#!/usr/bin/env ruby
require 'bundler/inline'
gemfile do
source 'https://rubygems.org'
gem 'json'
gem 'rest-client'
end
API_KEY = 'XXX' # put your api key here
city = ARGV.count > 0 ? ARGV.first : 'Hamburg,de'
body = RestClient.get("https://api.openweathermap.org/data/2.5/weather?q=#{city}&appid=#{API_KEY}&units=metric")
response = JSON.parse(body)
temp = response['main']['temp']
city = response['name']
weather = response['weather'][0]['description']
puts "Today it is #{temp}°C in #{city} with #{weather}."
Put this into a weather file, make it exectuable chmod +x weather and then put it into your PATH variable.