NAME main.rb SYNOPSIS a class factory and dsl for generating command line programs real quick URI http://codeforpeople.com/lib/ruby/ http://rubyforge.org/projects/codeforpeople/ http://github.com/ahoward/main INSTALL gem install main DESCRIPTION main.rb features the following: - unification of option, argument, keyword, and environment parameter parsing - auto generation of usage and help messages - support for mode/sub-commands - io redirection support - logging hooks using ruby's built-in logging mechanism - intelligent error handling and exit codes - use as dsl or library for building Main objects - parsing user defined ARGV and ENV - zero requirements for understanding the obtuse apis of *any* command line option parsers - leather pants in short main.rb aims to drastically lower the barrier to writing uniform command line applications. for instance, this program require 'main' Main { argument 'foo' option 'bar' def run p params['foo'] p params['bar'] exit_success! end } sets up a program which requires one argument, 'bar', and which may accept one command line switch, '--foo' in addition to the single option/mode which is always accepted and handled appropriately: 'help', '--help', '-h'. for the most part main.rb stays out of your command line namespace but insists that your application has at least a help mode/option. main.rb supports sub-commands in a very simple way require 'main' Main { mode 'install' do def run() puts 'installing...' end end mode 'uninstall' do def run() puts 'uninstalling...' end end } which allows a program, called 'a.rb', to be invoked as ruby a.rb install and ruby a.rb uninstall for simple programs main.rb is a real time saver but it's for more complex applications where main.rb's unification of parameter parsing, class configuration dsl, and auto-generation of usage messages can really streamline command line application development. for example the following 'a.rb' program: require 'main' Main { argument('foo'){ cast :int } keyword('bar'){ arity 2 cast :float defaults 0.0, 1.0 } option('foobar'){ argument :optional description 'the foobar option is very handy' } environment('BARFOO'){ cast :list_of_bool synopsis 'export barfoo=value' } def run p params['foo'].value p params['bar'].values p params['foobar'].value p params['BARFOO'].value end } when run with a command line of BARFOO=true,false,false ruby a.rb 42 bar=40 bar=2 --foobar=a will produce 42 [40.0, 2.0] "a" [true, false, false] while a command line of ruby a.rb --help will produce NAME a.rb SYNOPSIS a.rb foo [bar=bar] [options]+ PARAMETERS * foo [ 1 -> int(foo) ] * bar=bar [ 2 ~> float(bar=0.0,1.0) ] * --foobar=[foobar] [ 1 ~> foobar ] the foobar option is very handy * --help, -h * export barfoo=value and this shows how all of argument, keyword, option, and environment parsing can be declartively dealt with in a unified fashion - the dsl for all parameter types is the same - and how auto synopsis and usage generation saves keystrokes. the parameter synopsis is compact and can be read as * foo [ 1 -> int(foo) ] 'one argument will get processed via int(argument_name)' 1 : one argument -> : will get processed (the argument is required) int(foo) : the cast is int, the arg name is foo * bar=bar [ 2 ~> float(bar=0.0,1.0) ] 'two keyword arguments might be processed via float(bar=0.0,1.0)' 2 : two arguments ~> : might be processed (the argument is optional) float(bar=0.0,1.0) : the cast will be float, the default values are 0.0 and 1.0 * --foobar=[foobar] [ 1 ~> foobar ] 'one option with optional argument may be given directly' * --help, -h no synopsis, simple switch takes no args and is not required * export barfoo=value a user defined synopsis SAMPLES <========< samples/a.rb >========> ~ > cat samples/a.rb require 'main' ARGV.replace %w( 42 ) if ARGV.empty? Main { argument('foo'){ required # this is the default cast :int # value cast to Fixnum validate{|foo| foo == 42} # raises error in failure case description 'the foo param' # shown in --help } def run p params['foo'].given? p params['foo'].value end } ~ > ruby samples/a.rb true 42 <========< samples/b.rb >========> ~ > cat samples/b.rb require 'main' ARGV.replace %w( 40 1 1 ) if ARGV.empty? Main { argument('foo'){ arity 3 # foo will given three times cast :int # value cast to Fixnum validate{|foo| [40,1].include? foo} # raises error in failure case description 'the foo param' # shown in --help } def run p params['foo'].given? p params['foo'].values end } ~ > ruby samples/b.rb true [40, 1, 1] <========< samples/c.rb >========> ~ > cat samples/c.rb require 'main' ARGV.replace %w( foo=40 foo=2 bar=false ) if ARGV.empty? Main { keyword('foo'){ required # by default keywords are not required arity 2 cast :float } keyword('bar'){ cast :bool } def run p params['foo'].given? p params['foo'].values p params['bar'].given? p params['bar'].value end } ~ > ruby samples/c.rb true [40.0, 2.0] true false <========< samples/d.rb >========> ~ > cat samples/d.rb require 'main' ARGV.replace %w( --foo=40 -f2 ) if ARGV.empty? Main { option('foo', 'f'){ required # by default options are not required, we could use 'foo=foo' # above as a shortcut argument_required arity 2 cast :float } option('bar=[bar]', 'b'){ # note shortcut syntax for optional args # argument_optional # we could also use this method cast :bool default false } def run p params['foo'].given? p params['foo'].values p params['bar'].given? p params['bar'].value end } ~ > ruby samples/d.rb true [40.0, 2.0] nil false <========< samples/e.rb >========> ~ > cat samples/e.rb require 'main' ARGV.replace %w( x y argument ) Main { argument 'argument' option 'option' def run() puts 'run' end mode 'a' do option 'a-option' def run() puts 'a-run' end end mode 'x' do option 'x-option' def run() puts 'x-run' end mode 'y' do option 'y-option' def run() puts 'y-run' end end end } ~ > ruby samples/e.rb y-run <========< samples/f.rb >========> ~ > cat samples/f.rb require 'main' ARGV.replace %W( compress /data ) Main { argument('directory'){ description 'the directory to operate on' } option('force'){ description 'use a bigger hammer' } def run puts 'this is how we run when no mode is specified' end mode 'compress' do option('bzip'){ description 'use bzip compression' } def run puts 'this is how we run in compress mode' end end mode 'uncompress' do option('delete-after'){ description 'delete orginal file after uncompressing' } def run puts 'this is how we run in un-compress mode' end end } ~ > ruby samples/f.rb this is how we run in compress mode <========< samples/g.rb >========> ~ > cat samples/g.rb require 'main' ARGV.replace %w( 42 ) if ARGV.empty? Main { argument( 'foo' ) option( 'bar' ) run { puts "This is what to_options produces: #{params.to_options.inspect}" } } ~ > ruby samples/g.rb This is what to_options produces: {"help"=>nil, "foo"=>"42", "bar"=>nil} <========< samples/h.rb >========> ~ > cat samples/h.rb require 'main' # block-defaults are instance_eval'd in the main instance and be combined with # mixins # # ./h.rb #=> forty-two # ./h.rb a #=> 42 # ./h.rb b #=> 42.0 # Main { fattr :default_for_foobar => 'forty-two' option(:foobar) do default{ default_for_foobar } end mixin :foo do fattr :default_for_foobar => 42 end mixin :bar do fattr :default_for_foobar => 42.0 end run{ p params[:foobar].value } mode :a do mixin :foo end mode :b do mixin :bar end } ~ > ruby samples/h.rb "forty-two" <========< samples/j.rb >========> ~ > cat samples/j.rb #!/usr/bin/env ruby require 'open-uri' require 'main' require 'digest/sha2' # you have access to a sequel/amalgalite/sqlite db for free # Main { name :i_can_haz_db db { create_table(:mp3s) do primary_key :id String :url String :sha end unless table_exists?(:mp3s) } def run url = 'http://s3.amazonaws.com/drawohara.com.mp3/ween-voodoo_lady.mp3' mp3 = open(url){|fd| fd.read} sha = Digest::SHA2.hexdigest(mp3) db[:mp3s].insert(:url => url, :sha => sha) p db[:mp3s].all p db end } ~ > ruby samples/j.rb [{:url=>"http://s3.amazonaws.com/drawohara.com.mp3/ween-voodoo_lady.mp3", :sha=>"54c99ac7588dcfce1e70540b734805e9c69ff98dcca001e6f2bdec140fb0f9dc", :id=>1}, {:url=>"http://s3.amazonaws.com/drawohara.com.mp3/ween-voodoo_lady.mp3", :sha=>"54c99ac7588dcfce1e70540b734805e9c69ff98dcca001e6f2bdec140fb0f9dc", :id=>2}] #<Sequel::Amalgalite::Database: "amalgalite://Users/ahoward/.i_can_haz_db/db.sqlite"> DOCS test/main.rb vim -p lib/main.rb lib/main/*rb API section below HISTORY 5.1.0 - support for STATE_DIRNAME and STATE_BASENAME environment variables 5.0.0 ? 4.4.0 - support for automatic sequel/sqlite/amalgalite dbs for persistent state across invocations Main { db { create_table :foo do String key String val end unless table_exists? :foo } def run db[:foo].create(:key => 'using', :val => 'amalgalite') end } - support for automatic config files with auto populated template data Main { config :email => 'your.addy@gmail.com', :password => 'pa$$word' def run email = config[:email] end } - new paramter types :pathname, :path, :slug, :input, and :output - input/output parameters. can be filenames or '-' to supply stdin/stdout respectively Main { input :i output :o def run i = params[:i].value o = params[:o].value line = i.gets o.puts line end } - clean up warnings running with 'ruby -w' - fix a failing test - ability to ignore parameters in sub modes Main { argument :foo argument :bar def run p param[:bar].value end mode :ignoring do params[:foo].ignore! end } 4.0.0 - avoid duping ios. new methods Main.push_ios! and Main.pop_ios! are utilized for testing. this was done to make it simple to wrap daemon/servolux programs around main, althought not strictly required. not the version bump - there is not reason to expect existing main programs to break, but it *is* and interface change which requires a major version bump. 3.0.0 - major refactor to support modes via module/extend vs. subclassing. MIGHT NOT be backward compatible, though no known issues thus far. 2.9.0 - support ruby 1.9 2.8.3 - support for block defaults 2.8.2 - fixes and tests for negative arity/attr arguments, options, eg argument(:foo){ arity -1 } def run # ARGV == %w( a b c ) p foo #=> %w( a b c ) end thanks nathan 2.8.1 - move from attributes.rb to fattr.rb 2.8.0 - added 'to_options' method for Parameter::Table. this allows you to convert all the parameters to a simple hash. for example Main { option 'foo' argument 'baz' run { puts params.to_options.inspect } } 2.7.0 - removed bundled arrayfields and attributes. these are now dependancies mananged by rubygems. a.k.a. you must have rubygems installed for main to work. 2.6.0 - added 'mixin' feaature for storing, and later evaluating a block of code. the purpose of this is for use with modes where you want to keep your code dry, but may not want to define something in the base class for all to inherit. 'mixin' allows you to define the code to inherit once and the selectively drop it in child classes (modes) on demand. for example Main { mixin :foobar do option 'foo' option 'bar' end mode :install do mixin :foobar end mode :uninstall do mixin :foobar end mode :clean do end } - mode definitions are now deferred to the end of the Main block, so you can do this Main { mode 'a' do mixin :foo end mode 'b' do mixin :foo end def inherited_method 42 end mixin 'foo' do def another_inherited_method 'forty-two' end end } - added sanity check at end of paramter contruction - improved auto usage generation when arity is used with arguments - removed 'p' shortcut in paramerter dsl because it collided with Kernel.p. it's now called 'param'. this method is availble *inside* a parameter definition option('foo', 'f'){ synopsis "arity = #{ param.arity }" } - fixed bug where '--' did not signal the end of parameter parsing in a getoptlong compliant way - added (before/after)_parse_parameters, (before/after)_initialize, and (before/after)_run hooks - fixed bug where adding to usage via usage['my_section'] = 'custom message' totally horked the default auto generated usage message - updated dependancies in gemspec.rb for attributes (~> 5.0.0) and arrayfields (~> 4.3.0) - check that client code defined run, iff not wrap_run! is called. this is so mains with a mode, but no run defined, still function correctly when passed a mode - added new shortcut for creating accessors for parameters. for example option('foo'){ argument :required cast :int attr } def run p foo ### this attr will return the parameter's *value* end a block can be passed to specify how to extract the value from the parameter argument('foo'){ optional default 21 cast :int attr{|param| param.value * 2} } def run p foo #=> 42 end - fixed bug where 'abort("message")' would print "message" twice on exit if running under a nested mode (yes again - the fix in 2.4.0 wasn't complete) - added a time cast, which uses Time.parse argument('login_time'){ cast :time } - added a date cast, which uses Date.parse argument('login_date'){ cast :date } 2.5.0 - added 'examples', 'samples', and 'api' kewords to main dsl. each keyword takes a list of strings which will be included in the help message Main { examples "foobar example", "barfoo example" samples <<-txt do this don't do that txt api %( foobar string, hash barfoo hash, string ) } results in a usage message with sections like ... EXAMPLES foobar example barfoo example SAMPLES do this don't do that API foobar string, hash barfoo hash, string ... 2.4.0 - fixed bug where 'abort("message")' would print "message" twice on exit if running under a nested mode. - allowed parameters to be overridden completely in subclasses (modes) 2.3.0 - re-worked Main.new such that client code may define an #initialize methods and the class will continue to work. that is to say it's fine to do this Main { def initialize @a = 42 end def run p @a end mode 'foo' do def run p @a end end } the client #initialize will be called *after* main has done it's normal initialization so things like @argv, @env, and @stdin will all be there in initialize. of course you could have done this before but you'd have to both call super and call it with the correct arguments - now you can simply ignore it. 2.2.0 - added ability for parameter dsl error handlers to accept an argument, this will be passed the current error. for example argument(:x) do arity 42 error do |e| case e when Parameter::Arity ... end end - refined the mode parsing a bit: modes can now be abbreviated to uniqness and, when the mode is ambiuous, a nice error message is printed, for example: ambiguous mode: in = (inflate or install)? 2.1.0 - added custom error handling dsl for parameters, this includes the ability to prepend, append, or replace the standard error handlers: require 'main' Main { argument 'x' do error :before do puts 'this fires *before* normal error handling using #instance_eval...' end error do puts 'this fires *instead of* normal error handling using #instance_eval...' end error :after do puts 'this fires *after* normal error handling using #instance_eval...' end end run(){ p param['x'].given? } } - added ability to exit at any time bypassing *all* error handling using 'throw :exit, 42' where 42 is the desired exit status. throw without a status simply exits with 0. - added 'help!' method which simply dumps out usage and exits 2.0.0 - removed need for proxy.rb via Main::Base.wrap_run! - added error handling hooks for parameter parsing - bundled arrayfields, attributes, and pervasives although gems are tried first - softened error messages for parameter parsing errors: certain classes of errors are now 'softspoken' and print only the message, not the entire stacktrace, to stderr. much nicer for users. this is configurable. - added subcommand/mode support - added support for user defined exception handling on top level exceptions/exits - added support for negative arity. this users ruby's own arity semantics, for example: lambda{|*a|}.arity == -1 lambda{|a,*b|}.arity == -2 lambda{|a,b,*c|}.arity == -3 ... in otherwords parameters now support 'zero or more', 'one or more' ... 'n or more' argument semantics 1.0.0 - some improved usage messages from jeremy hinegardner 0.0.2 - removed dependancy on attributes/arrayfields. main now has zero gem dependancies. - added support for io redirection. redirection of stdin, stdout, and stderr can be done to any io like object or object that can be inerpreted as a pathname (object.to_s) - main objects can now easily be created and run on demand, which makes testing a breeze def test_unit_goodness! main = Main.new{ stdout StringIO.new stderr '/dev/null' def run puts 42 end } main.run main.stdout.rewind assert main.stdout.read == "42\n" end - added API section to readme and called it 'docs' - wrote a bunch more tests. there are now 42 of them. 0.0.1 initial version. this version extracts much of the functionality of alib's (gen install alib) Alib.script main program generator and also some of jim's freeze's excellent CommandLine::Aplication into what i hope is a simpler and more unified interface API Main { ########################################################################### # CLASS LEVEL API # ########################################################################### # # the name of the program, auto-set and used in usage # program 'foo.rb' # # a short description of program functionality, auto-set and used in usage # synopsis "foo.rb arg [options]+" # # long description of program functionality, used in usage iff set # description <<-hdoc this text will automatically be indented to the right level. it should describe how the program works in detail hdoc # # used in usage iff set # author 'ara.t.howard@gmail.com' # # used in usage # version '0.0.42' # # stdin/out/err can be anthing which responds to read/write or a string # which will be opened as in the appropriate mode # stdin '/dev/null' stdout '/dev/null' stderr open('/dev/null', 'w') # # the logger should be a Logger object, something 'write'-able, or a string # which will be used to open the logger. the logger_level specifies the # initalize verbosity setting, the default is Logger::INFO # logger(( program + '.log' )) logger_level Logger::DEBUG # # you can configure exit codes. the defaults are shown # exit_success # 0 exit_failure # 1 exit_warn # 42 # # the usage object is rather complex. by default it's an object which can # be built up in sections using the # # usage["BUGS"] = "something about bugs' # # syntax to append sections onto the already pre-built usage message which # contains program, synopsis, parameter descriptions and the like # # however, you always replace the usage object wholesale with one of your # chosing like so # usage <<-txt my own usage message txt ########################################################################### # MODE API # ########################################################################### # # modes are class factories that inherit from their parent class. they can # be nested *arbitrarily* deep. usage messages are tailored for each mode. # modes are, for the most part, independant classes but parameters are # always a superset of the parent class - a mode accepts all of it's parents # paramters *plus* and additional ones # option 'inherited-option' argument 'inherited-argument' mode 'install' do option 'force' do description 'clobber existing installation' end def run inherited_method() puts 'installing...' end mode 'docs' do description 'installs the docs' def run puts 'installing docs...' end end end mode 'un-install' do option 'force' do description 'remove even if dependancies exist' end def run inherited_method() puts 'un-installing...' end end def run puts 'no mode yo?' end def inherited_method puts 'superclass_method...' end ########################################################################### # PARAMETER API # ########################################################################### # # all the parameter types of argument|keyword|option|environment share this # api. you must specify the type when the parameter method is used. # alternatively used one of the shortcut methods # argument|keyword|option|environment. in otherwords # # parameter('foo'){ type :option } # # is synonymous with # # option('foo'){ } # option 'foo' { # # required - whether this paramter must by supplied on the command line. # note that you can create 'required' options with this keyword # required # or required true # # argument_required - applies only to options. # argument_required # argument :required # # argument_optional - applies only to options. # argument_optional # argument :optional # # cast - should be either a lambda taking one argument, or a symbol # designation one of the built in casts defined in Main::Cast. supported # types are :boolean|:integer|:float|:numeric|:string|:uri. built-in # casts can be abbreviated # cast :int # # validate - should be a lambda taking one argument and returning # true|false # validate{|int| int == 42} # # synopsis - should be a concise characterization of the paramter. a # default synopsis is built automatically from the parameter. this # information is displayed in the usage message # synopsis '--foo' # # description - a longer description of the paramter. it appears in the # usage also. # description 'a long description of foo' # # arity - indicates how many times the parameter should appear on the # command line. the default is one. negative arities are supported and # follow the same rules as ruby methods/procs. # arity 2 # # default - you can provide a default value in case none is given. the # alias 'defaults' reads a bit nicer when you are giving a list of # defaults for paramters of > 1 arity # defaults 40, 2 # # you can add custom per-parameter error handlers using the following # error :before do puts 'this fires *before* normal error handling using #instance_eval...' end error do puts 'this fires *instead of* normal error handling using #instance_eval...' end error :after do puts 'this fires *after* normal error handling using #instance_eval...' end } ########################################################################### # INSTANCE LEVEL API # ########################################################################### # # you must define a run method. it is the only method you must define. # def run # # all parameters are available in the 'params' hash and via the alias # 'param'. it can be indexed via string or symbol. the values are all # Main::Parameter objects # foo = params['foo'] # # the given? method indicates whether or not the parameter was given on # the commandline/environment, etc. in particular this will not be true # when a default value was specified but no parameter was given # foo.given? # # the list of all values can be retrieved via 'values'. note that this # is always an array. # p foo.values # # the __first__ value can be retrieved via 'value'. note that this # never an array. # p foo.value # # the methods debug|info|warn|error|fatal are delegated to the logger # object # info{ "this goes to the log" } # # you can set the exit_status at anytime. this status is used when # exiting the program. exceptions cause this to be ext_failure if, and # only if, the current value was exit_success. in otherwords an # un-caught exception always results in a failing exit_status # exit_status exit_failure # # a few shortcuts both set the exit_status and exit the program. # exit_success! exit_failure! exit_warn! end }
mattmccutchen/rubygem-main
a class factory and dsl for generating command line programs real quick
Ruby