How to create a terminal progress indicators in Ruby
For long running scripts it is useful to show a indicator for the progress in the terminal. Alternatively you can use a gem like paul/progress_bar.
count = User.count
index = 0
User.find_each do |user|
printf("Progress: %.2f%%\r", index.to_f / count * 100)
user.update!(role: 'member')
index += 1
end
Preview video
Related cards:
How to make changes to a Ruby gem (as a Rails developer)
At makandra, we've built a few gems over the years. Some of these are quite popular: spreewald (> 1M downloads), active_type (> 1M downloads), and geordi (> 200k downloads)
Developing a Ruby gem is different from developing Rails applications, w...
ActiveRecord: How to use ActiveRecord standalone within a Ruby script
Re-creating a complex ActiveRecord scenario quickly without setting up a full-blown Rails app can come in handy e.g. when trying to replicate a presumed bug in ActiveRecord with a small script.
# Based on http://www.jonathanleighton.com/artic...
How to get information about a gem (via CLI or at runtime from Ruby)
When you need information about a gem (like version(s) or install path(s)), you can use the gem binary from the command line, or the Gem API inside a ruby process at runtime.
gem binary (in a terminal)
You can get some information abou...
How to create a user with all privileges to MariaDB
Create a user without password (recommended)
Replace newuser with your desired username:
mysql -uroot -p
CREATE USER 'newuser'@'localhost' IDENTIFIED BY '';
GRANT ALL PRIVILEGES ON * . * TO 'newuser'@'localhost';
FLUSH PRIVILEGES;
exit;...
Ruby: How to use global variables for a conditional debugger
You can share a state in Ruby with global variables. Even if you should avoid them whenever possible, for debugging an application this could be temporary quite handy.
Exa...
Ruby: How to collect a Hash from an Array
There are many different methods that allow mapping an Array to a Hash in Ruby.
Array#to_h with a block (Ruby 2.6+)
You can call an array with a block that is called with each element. The block must return a [key, value] tuple.
This i...
Ruby: How to determine the absolute path relative to a file
If you want to get the path of a file relative to another, you can use the expand_path method with either the constant __FILE__ or the method __dir__. Read this card for more information about __FILE__ and __dir__.
##...
Ruby: How to connect to a host with expired SSL certificate
If you need to make an HTTPS connection to a host which uses an expired certificate, do not disable certificate verifications entirely. Doing that enables e.g. man in the middle attacks.
If you accept only a single expired and known certifica...
How to create a multiline map in SASS/SCSS
If you want to to create maps within SASS/SCSS-files, it normally works like this:
$some-map: (key1: value1, key2: value2)
However, some maps can get big really fast, if they are being used to contain all of the project's *icon name...
Ruby: How to grow or shrink an array to a given size
If you want to grow a Ruby Array, you might find out about #fill but it is not really what you are looking for. [1]
For arrays of unknown size that you want to grow or shrink to a fixed size, you need to define something yourself. Like the follo...