Drydock is a DSL for command-line apps. See bin/example for usage examples.
Provide a description for a command
# File lib/drydock.rb, line 706 def about(txt) @@command_descriptions += [txt] return if get_current_option_parser.is_a?(Symbol) get_current_option_parser.on "ABOUT: #{txt}" end
Define a command-specific action.
This is functionally very similar to option, but with an exciting and buoyant twist: Drydock keeps track of actions for each command (in addition to treating it like an option). When an action is specified on the command line Drydock looks for command_action or action_command methods in the command class.
action :E, :eat, "Eat something" command :oysters => Fresh::Oysters # Drydock will look for Fresh::Oysters#eat_oysters and Fresh::Oysters#oysters_eat.
# File lib/drydock.rb, line 593 def action(*args, &b) ret = option(*args, &b) # returns an array of all the current option names current_command_action << ret.last # the most recent is last end
Define a block to be called after the command. This is useful for stopping, closing, etc... the stuff in the before block.
# File lib/drydock.rb, line 507 def after(&b) @@after_block = b end
Used to create an alias to a defined command. Here's an example:
command :task do; ...; end alias_command :pointer, :task
Either name can be used on the command-line:
$ yourscript task [options] $ yourscript pointer [options]
Inside of the command definition, you have access to the command name that was used via obj.alias.
# File lib/drydock.rb, line 667 def alias_command(aliaz, cmd) return unless commands.has_key? cmd commands[canonize(aliaz)] = commands[cmd] end
Provide names for CLI arguments, in the order they appear.
$ yourscript sample malpeque zinqy argv :name, :flavour command :sample do |obj| obj.argv.name # => malpeque obj.argv.flavour # => zinqy end
# File lib/drydock.rb, line 421 def argv(*args) @@command_argv_names[@@command_index] ||= [] @@command_argv_names[@@command_index] += args.flatten end
Define a block to be called before the command. This is useful for opening database connections, etc...
# File lib/drydock.rb, line 501 def before(&b) @@before_block = b end
Canonizes a string (cmd) to the symbol for command names '-' is replaced with '_'
# File lib/drydock.rb, line 784 def canonize(cmd) return unless cmd return cmd if cmd.kind_of?(Symbol) cmd.to_s.tr('-', '_').to_sym end
# File lib/drydock.rb, line 764 def capture(io) @@capture = io end
Capture STDOUT or STDERR to prevent it from being printed.
capture(:stdout) do ... end
# File lib/drydock.rb, line 803 def capture_io(stream, &block) raise "We can only capture STDOUT or STDERR" unless stream == :stdout || stream == :stderr begin eval "$#{stream} = StringIO.new" block.call eval("$#{stream}").rewind # Otherwise we'll get nil result = eval("$#{stream}").read ensure eval "$#{stream} = #{stream.to_s.upcase}" # Put it back! end end
Define a command.
command :task do ... end
A custom command class can be specified using Hash syntax. The class must inherit from Drydock::Command (class CustomeClass < Drydock::Command)
command :task => CustomCommand do ... end
# File lib/drydock.rb, line 611 def command(*cmds, &b) cmd = cmds.shift # Should we accept aliases here? if cmd.is_a? Hash klass = cmd.values.first names = cmd.keys.first if names.is_a? Array cmd, cmds = names.shift, [names].flatten.compact else cmd = names end raise "#{klass} is not a subclass of Drydock::Command" unless klass.ancestors.member?(Drydock::Command) c = klass.new(cmd, &b) # A custom class was specified else c = Drydock::Command.new(cmd, &b) end @@command_descriptions[@@command_index] ||= "" @@command_actions[@@command_index] ||= [] @@command_argv_names[@@command_index] ||= [] c.desc = @@command_descriptions[@@command_index] c.actions = @@command_actions[@@command_index] c.argv.fields = @@command_argv_names[@@command_index] # Default Usage Banner. # Without this, there's no help displayed for the command. option_parser = get_option_parser(@@command_index) if option_parser.is_a?(OptionParser) && option_parser.banner !~ /^USAGE/ usage "#{c.executable} #{c.cmd}" end @@commands[c.cmd] = c @@command_index_map[c.cmd] = @@command_index @@command_index += 1 # This will point to the next command # Created aliases to the command using any additional command names # i.e. command :something, :sumpin => Something cmds.each { |aliaz| command_alias(cmd, aliaz); } unless cmds.empty? c # Return the Command object end
Returns true if a command with the name cmd has been defined.
# File lib/drydock.rb, line 777 def command?(cmd) name = canonize(cmd) @@commands.has_key? name end
Identical to alias_command with reversed arguments. For whatever reason I forget the order so Drydock supports both. Tip: the argument order matches the method name.
# File lib/drydock.rb, line 675 def command_alias(cmd, aliaz) return unless commands.has_key? cmd commands[canonize(aliaz)] = commands[cmd] end
An array of the currently defined commands names
# File lib/drydock.rb, line 686 def command_names @@commands.keys.collect { |cmd| decanonize(cmd); } end
A hash of the currently defined Drydock::Command objects
# File lib/drydock.rb, line 681 def commands @@commands end
Enable or disable debug output.
debug :on debug :off
Calling without :on or :off will toggle the value.
# File lib/drydock.rb, line 398 def debug(toggle=false) if toggle.is_a? Symbol @@debug = true if toggle == :on @@debug = false if toggle == :off else @@debug = (!@@debug) end end
Returns true if debug output is enabled.
# File lib/drydock.rb, line 408 def debug? @@debug end
Returns a string version of cmd, decanonized. Lowercase, '_' is replaced with '-'
# File lib/drydock.rb, line 792 def decanonize(cmd) return unless cmd cmd.to_s.tr('_', '-') end
Define a default command. You can specify a command name that has been or will be defined in your script:
default :task
Or you can supply a block which will be used as the default command:
default do |obj| # This command will be named "default" # ... end default :hullinspector do # This one will be named "hullinspector" # ... end
If with_args is specified, the default command will receive all unknown values as arguments. This is necessary to define explicitly because drydock parses arguments expecting a command name. If the default command accepts arguments and with_args is not specified, drydock will raise an unknown command exception for the first argument.
# File lib/drydock.rb, line 468 def default(cmd=nil, with_args=false, &b) raise "Calling default requires a command name or a block" unless cmd || b # Creates the command and returns the name or just stores given name @@default_command = (b) ? command(cmd || :default, &b).cmd : canonize(cmd) # IDEA: refactor out the argument parser to support different types of CLI @@default_command_with_args = with_args ? true : false @@default_command end
Is cmd the default command?
# File lib/drydock.rb, line 478 def default?(cmd) return false if @@default_command.nil? (@@default_command == canonize(cmd)) end
# File lib/drydock.rb, line 484 def default_with_args?; @@default_command_with_args; end
Deprecated. Use about.
# File lib/drydock.rb, line 712 def desc(txt) STDERR.puts "'desc' is deprecated. Please use 'about' instead." about(txt) end
Define a global option. See option for more info.
# File lib/drydock.rb, line 539 def global_option(*args, &b) args.unshift(@@global_opts_parser) @@global_option_names << option_parser(args, &b) end
Define the default global usage banner. This is displayed with "script -h".
# File lib/drydock.rb, line 513 def global_usage(msg) @@global_opts_parser.banner = "USAGE: #{msg}" end
Return true if a command has been executed.
# File lib/drydock.rb, line 730 def has_run? @@has_run end
Tell the Drydock parser to ignore something. Drydock will currently only listen to you if you tell it to "ignore :options", otherwise it will ignore you!
what the thing to ignore. When it equals :options Drydock will not parse the command-specific arguments. It will pass the arguments directly to the Command object. This is useful when you want to parse the arguments in some a way that's too crazy, dangerous for Drydock to handle automatically.
# File lib/drydock.rb, line 534 def ignore(what=:nothing) @@command_opts_parser[@@command_index] = :ignore if what == :options || what == :all end
Define a command-specific option.
args is passed directly to OptionParser.on so it can contain anything that's valid to that method. If a class is included, it will tell OptionParser to expect a value otherwise it assumes a boolean value. Some examples:
option :h, :help, "Displays this message" option '-l x,y,z', '--lang=x,y,z', Array, "Requested languages" You can also supply a block to fiddle with the values. The final value becomes the option's value: option :m, :max, Integer, "Maximum threshold" do |v| v = 100 if v > 100 v end
All calls to option must come before the command they're associated to. Example:
option :t, :tasty, "A boolean switch" option :reason, String, "Requires a parameter" command :task do |obj|; obj.options.tasty # => true obj.options.reason # => I made the sandwich! end
When calling your script with a specific command-line option, the value is available via obj.longname inside the command block.
# File lib/drydock.rb, line 576 def option(*args, &b) args.unshift(get_current_option_parser) current_command_option_names << option_parser(args, &b) end
The project name. This is currently only used when printing list of commands (see: Drydock::Command#show_commands). It may be used elsewhere in the future.
# File lib/drydock.rb, line 429 def project(txt=nil) return @@project unless txt #begin # require txt.downcase #rescue LoadError => ex # Drydock.run = false # Prevent execution at_exit # abort "Problem during require: #{ex.message}" #end @@project = txt end
Has the project been set?
# File lib/drydock.rb, line 443 def project? (defined?(@@project) && !@@project.nil?) end
Execute the given command. By default, Drydock automatically executes itself and provides handlers for known errors. You can override this functionality by calling Drydock.run! yourself. Drydock will only call run! once.
# File lib/drydock.rb, line 738 def run!(argv=[], stdin=STDIN) return if has_run? @@has_run = true raise NoCommandsDefined.new if commands.empty? global_options, cmd_name, command_options, argv = process_arguments(argv) stdin = (defined? @@stdin_block) ? @@stdin_block.call(stdin, []) : stdin command_obj = get_command(cmd_name) command_obj.prepare(cmd_name, argv, stdin, global_options, command_options) # Execute before block @@before_block.call(command_obj) if defined? @@before_block # Execute the requested command. We'll capture STDERR or STDOUT if desired. @@captured = capture? ? capture_io(@@capture) { command_obj.call } : command_obj.call # Execute after block @@after_block.call(command_obj) if defined? @@after_block rescue OptionParser::InvalidOption => ex raise Drydock::InvalidArgument.new(ex.args) rescue OptionParser::MissingArgument => ex raise Drydock::MissingArgument.new(ex.args) end
Disable automatic execution (enabled by default)
Drydock.run = false
# File lib/drydock.rb, line 725 def run=(v) @@run = (v.is_a?(TrueClass)) ? true : false end
Returns true if automatic execution is enabled.
# File lib/drydock.rb, line 718 def run? @@run && has_run? == false end
Define a block for processing STDIN before the command is called. The command block receives the return value of this block as obj.stdin:
command :task do |obj|; obj.stdin # => ... end
If a stdin block isn't defined, stdin above will be the STDIN IO handle.
# File lib/drydock.rb, line 495 def stdin(&b) @@stdin_block = b end
The trawler catches any and all unknown commands that pass through Drydock. It's like the captain of aliases. cmd is the name of the command to direct unknowns to.
trawler :command_name
# File lib/drydock.rb, line 696 def trawler(cmd) @@trawler = cmd end
Has the trawler been set?
# File lib/drydock.rb, line 701 def trawler? !@@trawler.nil? && !@@trawler.to_s.empty? end
Define a command-specific usage banner. This is displayed with "script command -h"
# File lib/drydock.rb, line 519 def usage(msg) # The default value given by OptionParser starts with "Usage". That's how # we know we can clear it. get_current_option_parser.banner = "" if get_current_option_parser.banner =~ /^Usage:/ get_current_option_parser.banner << "USAGE: #{msg}" << $/ end
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