#Script
history_file = File.read(File.expand_path("~/.zsh_history"))
history_file = history_file.split(": ")
history_file.collect! { |item| item=item.split(";")[1].split(" ")[0]}
puts history_file

#error
frequently_used_commands.rb:9:in `block in <main>': undefined method `split' for nil:NilClass (NoMethodError)
	from frequently_used_commands.rb:9:in `collect!'
	from frequently_used_commands.rb:9:in `<main>'