Sister dir path in Ruby

In Ruby, getting the sister directory path can be done using the File.dirname method.

Here's an example:

Suppose we have the following directory structure:

parent_dir/

├── sister_dir/

└── current_dir/

If we're currently in the current_dir, we can get the path of the sister_dir like this:

sister_dir_path = File.join(File.dirname(__dir__), "sister_dir")
puts sister_dir_path
# Output: /path/to/parent_dir/sister_dir

Another example:

require 'pathname'

current_dir_path = Pathname.new(__FILE__).realpath.parent.to_s

sister_dir_path = File.join(File.dirname(current_dir_path), "sister_dir")

puts sister_dir_path

# Output: /path/to/parent_dir/sister_dir

In this example, we're using Pathname to get the absolute path of the current directory (current_dir). We then use File.dirname to remove the last part of the path (i.e. current_dir), leaving us with the path to the parent directory. We then use File.join to append the name of the sister directory (sister_dir) to the parent directory path, giving us the final path to the sister_dir.