Commander.js

The complete solution for node.js command-line interfaces. Commander exports a global object which is convenient for quick programs. For larger programs which may use commander in multiple ways, including unit testing, it is better to create a local Command object to use. Each option can have a short flag (single character) and a long name, separated by a comma or space or vertical bar ('|'). Multiple short flags may optionally be combined in a single argument following the dash: boolean flags, followed by a single option taking a value (possibly followed by the value). You may specify a function to do custom processing of option-arguments. The callback function receives two parameters, the user specified option-argument and the previous value for the option. It returns the new value for the option. This allows you to coerce the option-argument to the desired type, or accumulate values, or do entirely custom processing.