ame

Ame Ame provides a simple command-line interface API for Ruby¹. It can be used to provide both simple interfaces like that of ‹rm›² and complex ones like that of ‹git›³. It uses Ruby’s own classes, methods, and argument lists to provide an interface that is both simple to use from the command-line side and from the Ruby side. The provided command-line interface is flexible and follows commond standards for command-line processing. ¹ See http://ruby-lang.org/ ² See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/rm.html ³ See http://git-scm.com/docs/ § Usage Let’s begin by looking at two examples, one where we mimic the POSIX¹ command-line interface to the ‹rm› command. Looking at the entry² in the standard, ‹rm› takes the following options: = -f. = Do not prompt for confirmation. = -i. = Prompt for confirmation. = -R. = Remove file hierarchies. = -r. = Equivalent to /-r/. It also takes the following arguments: = FILE. = A pathname or directory entry to be removed. And actually allows one or more of these /FILE/ arguments to be given. We also note that the ‹rm› command is described as a command to “remove directory entries”. ¹ See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/contents.html ² See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/rm.html Let’s turn this specification into one using Ame’s API. We begin by adding a flag for each of the options listed above: class Rm < Ame::Root flag 'f', '', false, 'Do not prompt for confirmation' flag 'i', '', nil, 'Prompt for confirmation' do |options| options['f'] = false end flag 'R', '', false, 'Remove file hierarchies' flag 'r', '', nil, 'Equivalent to -R' do |options| options['r'] = true end A flag¹ is a boolean option that doesn’t take an argument. Each flag gets a short and long name, where an empty name means that there’s no ...