Commands implemented through OptionsParser.

src/main.cr

@@ -37,6 +37,19 @@ module Baguette::Base
 	include Baguette::Log
 end
 
+class OptionParser
+	def to_s(io : IO) : Nil
+		if banner = @banner
+			io << banner << '\n'
+		end
+
+		@flags.select(&.starts_with? "    -").join io, '\n'
+
+		io << "\ncommands:\n"
+		@flags.select{ |x| !x.starts_with? "    -" }.join io, '\n'
+	end
+end
+
 Colorize.on_tty_only!
 
 # CAUTION
@@ -50,71 +63,86 @@ class RootFS::Context
 		@configuration = Baguette::Configuration.new "rootfs"
 	end
 
-	def print_commands_help
-		STDOUT << "commands:" << "\n"
-		STDOUT << "     new     <template> <rootfs-directory>\n"
-		STDOUT << "     save    <rootfs-directory> <snapshot-directory>\n"
-		STDOUT << "     restore <rootfs-directory> <snapshot-directory>\n"
-		# Other commands are not implemented at the moment.
-	end
-
 	def run
 		options_parser = uninitialized OptionParser
 
 		commands = {
-			"new" => ->(args : Array(String)){
+			:new => ->(args : Array(String)){
 				RootFS.new args[1], args[0]
 			},
-			"save" => ->(args : Array(String)){
+			:save => ->(args : Array(String)){
 				RootFS.load(args[0]).save(args[1])
 			},
-			"restore" => ->(args : Array(String)){
+			:restore => ->(args : Array(String)){
 				RootFS.load(args[0]).restore(args[1])
 			},
-			"mount" => ->(args : Array(String)){
+			:mount => ->(args : Array(String)){
 				RootFS.load(args[0]).mount(args[1]?)
 			},
-			"unmount" => ->(args : Array(String)){
+			:unmount => ->(args : Array(String)){
 				RootFS.load(args[0]).unmount(args[1]?)
-			},
-			# FIXME: This needs access to the list of commands.
-			"help" => ->(args : Array(String)){
-				STDOUT << options_parser << "\n\n"
-				print_commands_help
 			}
 		}
 
-		command   = uninitialized String
+		command   = nil
 		arguments = uninitialized Array(String)
 
 		options_parser = OptionParser.parse do |parser|
 			parser.banner = "usage: #{@configuration.application_name} <command> [options]"
 
+			parser.on "new", "Creates a new rootfs." do
+				parser.banner = "usage: #{@configuration.application_name} new <template> <rootfs-directory>"
+
+				command = :new
+			end
+
+			parser.on "save", "Creates a snapshot of a rootfs." do
+				parser.banner = "usage: #{@configuration.application_name} save <rootfs-directory> <snapshot-directory>"
+				command = :save
+			end
+
+			parser.on "restore", "Restores a rootfs from a snapshot." do
+				parser.banner = "usage: #{@configuration.application_name} restore <rootfs-directory> <snapshot-directory>"
+				command = :restore
+			end
+
+			parser.on "mount", "Bind-mount a directory in a rootfs." do
+				parser.banner = "usage: #{@configuration.application_name} mount <rootfs-directory> [mount-point]"
+				command = :mount
+			end
+
+			parser.on "unmount", "Unmount a directory from a rootfs." do
+				parser.banner = "usage: #{@configuration.application_name} unmount <rootfs-directory> [mount-point]"
+				command = :unmount
+			end
+
 			parser.on "-c", "--color", "Forces the use of colors." do
 				Colorize.enabled = true
 			end
 
 			parser.on "-h", "--help", "Displays this help message." do
-				STDOUT << parser << "\n\n"
+				puts parser
-				print_commands_help
 				exit 0
 			end
 
-			# FIXME: This leads to unusual behaviors when using the CLI.
-			#        Replace by dedicated executables.
 			parser.unknown_args do |args|
-				# args => Array(String)
+				if command.nil?
+					raise "no command provided" if args.size < 1
+				end
 
-				raise "no command provided" if args.size < 1
-
-				command = args.shift
 				arguments = args
 			end
 		end
 
+		if command.nil?
+			puts options_parser
+			exit 1
+		end
+
 		if proc = commands[command]?
 			proc.call(arguments)
 		else
+			# FIXME: This is an internal error. It shouldn’t trigger.
 			raise "unrecognized command: #{command}"
 		end
 	rescue e