decaffeinate:tldr:560f7
The command "decaffeinate ${filename-coffee}" is written in a shell scripting language. In this command, "decaffeinate" is the name of an executable or script that is being executed. It is a tool used to convert CoffeeScript code (a programming language that compiles into JavaScript) into modern ECMAScript (JavaScript) code.
"${filename-coffee}" is a placeholder for the actual filename of a CoffeeScript file that you want to convert. By using the syntax "${variable-name}", it implies that "filename-coffee" is a variable that holds the name of a CoffeeScript file.
So, when you run this command by replacing "${filename-coffee}" with the actual CoffeeScript file's name, it will execute the "decaffeinate" tool on that file, converting it into JavaScript code.