And 90% of that 90% has that tiny modification that is a nightmare to debug.
require 'pry'; binding.pry
This is, in fact, 2017. One might call it the current year. The stone knives and bearskins of shell scripting have not kept apace with, like...anything else in our industry. You might be comfortable with them, but that doesn't make it easy, it means you have frayed countless synapses learning it.