What does “<<-” mean in Ruby?

Question

For example:

code = <<-EOH
    bundle install
    bundle exec unicorn -c /etc/unicorn.cfg -D
EOH

What does this code do? What is

Answer 1

There is also a newer HEREDOC syntax for Ruby <<~END that more closely resembles what you would typically see in most shells and other languages with the ~ instead of the - to tell Ruby to strip the leading whitespace to match the least indented line in the block.

https://infinum.co/the-capsized-eight/multiline-strings-ruby-2-3-0-the-squiggly-heredoc