5 posts about #programming

Find files with largest amount of lines in your project

Ever needed to find the file with the largest amount of lines in your project? Use the snippet below to list all files and their line count, neatly sorted from smallest to largest.

find . -type f -print0 | xargs -0 wc -l | sort -n

This translates to the following:

find . -type f -print0 # Find all regular files in this dir and pipe them into xargs with \0 as separators.
xargs -0 wc -l # For each file contents, count the amount of lines in it and...
sort -n # Sort them numerically.

Quick Ruby client for Marqo (VectorDB)

Marqo is a cool vector DB that lets you store facts and then query them later with natural language. You can install Marqo using Docker, which I managed to do today on my M1 Mac. Just make sure you stop whatever ElasticSearch or OpenSearch instances you may already have running on your machine first, since Marqo wants to use its own.

Once you have it running, you can use the following Ruby class to access it in your Rails project.

require 'httparty'

class Marqo
  include HTTParty

  base_uri 'http://localhost:8882'

  def initialize(auth = { username: 'admin', password: 'admin' })
    @auth = auth

  def store(index_name, name, detail)
    options = {
      headers: { 'Content-Type' => 'application/json' },
      body: [{name: name, detail: detail}].to_json
    self.class.post("/indexes/#{index_name}/documents", options)

  def search(index_name, query)
    options = {
      basic_auth: @auth,
      headers: { 'Content-Type' => 'application/json' },
      body: { q: query }.to_json
    self.class.post("/indexes/#{index_name}/search", options)

  def self.client
    @client ||= new

Underscores are not allowed as part of domain names

According to rfc1035, underscores (_) are not allowed as part of domain names.

The labels must follow the rules for ARPANET host names. They must start with a letter, end with a letter or digit, and have as interior characters only letters, digits, and hyphen (-). There are also some restrictions on the length. Labels must be 63 characters or less.

This means domain names like my_domain.com or sub_domain.main-domain.com are invalid.

Special thanks to @jclopezdev for finding this out.

StimulusReflex + ActiveStorage + Localhost

As it turns out, when you're working with StimulusReflex and ActiveStorage to store Images for a given model, you need to setup default_url_options in development.rb to

 config.action_controller.default_url_options ={ host: 'localhost', port: 3000 }

otherwise, they will be rendered with www.example.org/ host and won't show properly

Strip and downcase email addresses if you're using them as lookup keys for anything

Seems like something I need to learn every few years, and recently popped up on one of my side projects. If you're relying on email addresses as lookup keys, for instance in authentication/login scenarios, then standardize on lowercase and strip whitespace for good measure.

This came up when a customer was not able to get inbound email processing to work for his account. Turns out that his user record had a properly downcased email, but his SMTP server was sending his email address with capitalization. Some string massaging fixed the immediate issue.

User.find_by(email: reply_params["sender"].to_s.downcase)

After putting this fix in, I found everywhere else in the system that email addresses come in as input and gave them the same treatment.