FM / man3

/usr/local/share/man/man3

Name	Size	Mode	Actions
App::Prove.3pm	10508	0444	edit dl rm
App::Prove::State.3pm	6005	0444	edit dl rm
App::Prove::State::Result.3pm	5619	0444	edit dl rm
App::Prove::State::Result::Test.3pm	5051	0444	edit dl rm
AppConfig.3pm	35289	0444	edit dl rm
AppConfig::Args.3pm	7992	0444	edit dl rm
AppConfig::CGI.3pm	6609	0444	edit dl rm
AppConfig::File.3pm	12614	0444	edit dl rm
AppConfig::Getopt.3pm	7444	0444	edit dl rm
AppConfig::State.3pm	24972	0444	edit dl rm
AppConfig::Sys.3pm	6695	0444	edit dl rm
Archive::Tar.3pm	44061	0444	edit dl rm
Archive::Tar::File.3pm	11083	0444	edit dl rm
Archive::Zip.3pm	69985	0444	edit dl rm
Archive::Zip::FAQ.3pm	18437	0444	edit dl rm
Archive::Zip::MemberRead.3pm	6734	0444	edit dl rm
Archive::Zip::Tree.3pm	2875	0444	edit dl rm
B::COW.3pm	5163	0444	edit dl rm
Canary::Stability.3pm	3727	0444	edit dl rm
CDB_File.3pm	14318	0444	edit dl rm
common::sense.3pm	0	0444	edit dl rm
Compress::Raw::Bzip2.3pm	13463	0444	edit dl rm
Compress::Raw::Zlib.3pm	42082	0444	edit dl rm
Compress::Zlib.3pm	38719	0444	edit dl rm
CPAN::Meta.3pm	15923	0444	edit dl rm
CPAN::Meta::Converter.3pm	6594	0444	edit dl rm
CPAN::Meta::Feature.3pm	4322	0444	edit dl rm
CPAN::Meta::History.3pm	7855	0444	edit dl rm
CPAN::Meta::History::Meta_1_0.3pm	9973	0444	edit dl rm
CPAN::Meta::History::Meta_1_1.3pm	12410	0444	edit dl rm
CPAN::Meta::History::Meta_1_2.3pm	22224	0444	edit dl rm
CPAN::Meta::History::Meta_1_3.3pm	23974	0444	edit dl rm
CPAN::Meta::History::Meta_1_4.3pm	24565	0444	edit dl rm
CPAN::Meta::Merge.3pm	5285	0444	edit dl rm
CPAN::Meta::Prereqs.3pm	7380	0444	edit dl rm
CPAN::Meta::Requirements.3pm	12308	0444	edit dl rm
CPAN::Meta::Spec.3pm	45592	0444	edit dl rm
CPAN::Meta::Validator.3pm	4215	0444	edit dl rm
CPAN::Meta::YAML.3pm	4230	0444	edit dl rm
Crypt::OpenSSL::Random.3pm	5634	0444	edit dl rm
Curses.3pm	37580	0444	edit dl rm
Curses::UI.3pm	15619	0444	edit dl rm
Curses::UI::Buttonbox.3pm	8908	0444	edit dl rm
Curses::UI::Calendar.3pm	8203	0444	edit dl rm
Curses::UI::Checkbox.3pm	6509	0444	edit dl rm
Curses::UI::Color.3pm	5903	0444	edit dl rm
Curses::UI::Common.3pm	6498	0444	edit dl rm
Curses::UI::Container.3pm	9041	0444	edit dl rm
Curses::UI::Dialog::Basic.3pm	5213	0444	edit dl rm
Curses::UI::Dialog::Calendar.3pm	4761	0444	edit dl rm
Curses::UI::Dialog::Dirbrowser.3pm	5369	0444	edit dl rm
Curses::UI::Dialog::Error.3pm	4307	0444	edit dl rm
Curses::UI::Dialog::Filebrowser.3pm	6889	0444	edit dl rm
Curses::UI::Dialog::Progress.3pm	5774	0444	edit dl rm
Curses::UI::Dialog::Question.3pm	5277	0444	edit dl rm
Curses::UI::Dialog::Status.3pm	4765	0444	edit dl rm
Curses::UI::Label.3pm	7333	0444	edit dl rm
Curses::UI::Listbox.3pm	11988	0444	edit dl rm
Curses::UI::Menubar.3pm	8110	0444	edit dl rm
Curses::UI::Notebook.3pm	9140	0444	edit dl rm
Curses::UI::PasswordEntry.3pm	3743	0444	edit dl rm
Curses::UI::Popupmenu.3pm	7431	0444	edit dl rm
Curses::UI::Progressbar.3pm	5891	0444	edit dl rm
Curses::UI::Radiobuttonbox.3pm	4069	0444	edit dl rm
Curses::UI::Searchable.3pm	6668	0444	edit dl rm
Curses::UI::TextEditor.3pm	14171	0444	edit dl rm
Curses::UI::TextEntry.3pm	3623	0444	edit dl rm
Curses::UI::TextViewer.3pm	3670	0444	edit dl rm
Curses::UI::Tutorial.3pm	8555	0444	edit dl rm
Curses::UI::Widget.3pm	25675	0444	edit dl rm
Curses::UI::Window.3pm	5084	0444	edit dl rm
Cwd.3pm	7183	0444	edit dl rm
Date::Format.3pm	7291	0444	edit dl rm
Date::Language.3pm	3809	0444	edit dl rm
Date::Language::Bulgarian.3pm	3675	0444	edit dl rm
Date::Language::Hungarian.3pm	3091	0444	edit dl rm
Date::Parse.3pm	5402	0444	edit dl rm
Digest::SHA.3pm	25759	0444	edit dl rm
Expect.3pm	60229	0444	edit dl rm
ExtUtils::CBuilder.3pm	11923	0444	edit dl rm
ExtUtils::CBuilder::Platform::Windows.3pm	3117	0444	edit dl rm
ExtUtils::Command.3pm	5942	0444	edit dl rm
ExtUtils::Command::MM.3pm	5723	0444	edit dl rm
ExtUtils::Liblist.3pm	12679	0444	edit dl rm
ExtUtils::MakeMaker.3pm	79357	0444	edit dl rm
ExtUtils::MakeMaker::Config.3pm	2587	0444	edit dl rm
ExtUtils::MakeMaker::FAQ.3pm	26829	0444	edit dl rm
ExtUtils::MakeMaker::Locale.3pm	11168	0444	edit dl rm
ExtUtils::MakeMaker::Tutorial.3pm	8389	0444	edit dl rm
ExtUtils::Manifest.3pm	11961	0444	edit dl rm
ExtUtils::Mkbootstrap.3pm	3459	0444	edit dl rm
ExtUtils::Mksymlists.3pm	6699	0444	edit dl rm
ExtUtils::MM.3pm	2829	0444	edit dl rm
ExtUtils::MM_AIX.3pm	3044	0444	edit dl rm
ExtUtils::MM_Any.3pm	31129	0444	edit dl rm
ExtUtils::MM_BeOS.3pm	2798	0444	edit dl rm
ExtUtils::MM_Cygwin.3pm	3569	0444	edit dl rm
ExtUtils::MM_Darwin.3pm	2688	0444	edit dl rm
ExtUtils::MM_DOS.3pm	3021	0444	edit dl rm
ExtUtils::MM_MacOS.3pm	2987	0444	edit dl rm
ExtUtils::MM_NW5.3pm	3200	0444	edit dl rm
ExtUtils::MM_OS2.3pm	2886	0444	edit dl rm
ExtUtils::MM_QNX.3pm	2942	0444	edit dl rm
ExtUtils::MM_Unix.3pm	21419	0444	edit dl rm
ExtUtils::MM_UWIN.3pm	3051	0444	edit dl rm
ExtUtils::MM_VMS.3pm	14900	0444	edit dl rm
ExtUtils::MM_VOS.3pm	2926	0444	edit dl rm
ExtUtils::MM_Win32.3pm	5919	0444	edit dl rm
ExtUtils::MM_Win95.3pm	3276	0444	edit dl rm
ExtUtils::MY.3pm	2764	0444	edit dl rm
ExtUtils::testlib.3pm	2690	0444	edit dl rm
File::GlobMapper.3pm	11447	0444	edit dl rm
File::HomeDir.3pm	18212	0444	edit dl rm
File::HomeDir::Darwin.3pm	3232	0444	edit dl rm
File::HomeDir::Darwin::Carbon.3pm	3517	0444	edit dl rm
File::HomeDir::Darwin::Cocoa.3pm	3446	0444	edit dl rm
File::HomeDir::Driver.3pm	3101	0444	edit dl rm
File::HomeDir::FreeDesktop.3pm	3487	0444	edit dl rm
File::HomeDir::MacOS9.3pm	3499	0444	edit dl rm
File::HomeDir::Test.3pm	3534	0444	edit dl rm
File::HomeDir::Unix.3pm	3638	0444	edit dl rm
File::HomeDir::Windows.3pm	4891	0444	edit dl rm
File::Path.3pm	31030	0444	edit dl rm
File::Slurp.3pm	23626	0444	edit dl rm
File::Spec.3pm	13784	0444	edit dl rm
File::Spec::AmigaOS.3pm	2826	0444	edit dl rm
File::Spec::Cygwin.3pm	3957	0444	edit dl rm
File::Spec::Epoc.3pm	3251	0444	edit dl rm
File::Spec::Functions.3pm	3799	0444	edit dl rm
File::Spec::Mac.3pm	18664	0444	edit dl rm
File::Spec::OS2.3pm	3118	0444	edit dl rm
File::Spec::Unix.3pm	9837	0444	edit dl rm
File::Spec::VMS.3pm	6389	0444	edit dl rm
File::Spec::Win32.3pm	6451	0444	edit dl rm
File::Temp.3pm	36799	0444	edit dl rm
File::Which.3pm	9746	0444	edit dl rm
Getopt::Long.3pm	52647	0444	edit dl rm
HDB.3pm	10947	0444	edit dl rm
HDB::CMDS.3pm	18894	0444	edit dl rm
HDB::Encode.3pm	7863	0444	edit dl rm
HDB::Object.3pm	10057	0444	edit dl rm
HTML::AsSubs.3pm	8586	0444	edit dl rm
HTML::Element.3pm	70793	0444	edit dl rm
HTML::Element::traverse.3pm	15984	0444	edit dl rm
HTML::Form.3pm	28158	0444	edit dl rm
HTML::Parse.3pm	8277	0444	edit dl rm
HTML::Tree.3pm	9982	0444	edit dl rm
HTML::Tree::AboutObjects.3pm	37918	0444	edit dl rm
HTML::Tree::AboutTrees.3pm	58534	0444	edit dl rm
HTML::Tree::Scanning.3pm	34385	0444	edit dl rm
HTML::TreeBuilder.3pm	30138	0444	edit dl rm
HTTP::Tiny.3pm	27709	0444	edit dl rm
IO::AtomicFile.3pm	5381	0444	edit dl rm
IO::Compress::Base.3pm	3506	0444	edit dl rm
IO::Compress::Bzip2.3pm	23260	0444	edit dl rm
IO::Compress::Deflate.3pm	26768	0444	edit dl rm
IO::Compress::FAQ.3pm	26718	0444	edit dl rm
IO::Compress::Gzip.3pm	34489	0444	edit dl rm
IO::Compress::RawDeflate.3pm	27134	0444	edit dl rm
IO::Compress::Zip.3pm	40870	0444	edit dl rm
IO::InnerFile.3pm	6035	0444	edit dl rm
IO::Lines.3pm	3783	0444	edit dl rm
IO::Pty.3pm	8579	0444	edit dl rm
IO::Scalar.3pm	10679	0444	edit dl rm
IO::ScalarArray.3pm	10528	0444	edit dl rm
IO::Stringy.3pm	4049	0444	edit dl rm
IO::Tty.3pm	8348	0444	edit dl rm
IO::Tty::Constant.3pm	10012	0444	edit dl rm
IO::Uncompress::AnyInflate.3pm	32800	0444	edit dl rm
IO::Uncompress::AnyUncompress.3pm	30767	0444	edit dl rm
IO::Uncompress::Base.3pm	3518	0444	edit dl rm
IO::Uncompress::Bunzip2.3pm	29171	0444	edit dl rm
IO::Uncompress::Gunzip.3pm	31719	0444	edit dl rm
IO::Uncompress::Inflate.3pm	29915	0444	edit dl rm
IO::Uncompress::RawInflate.3pm	29563	0444	edit dl rm
IO::Uncompress::Unzip.3pm	31279	0444	edit dl rm
IO::Wrap.3pm	10664	0444	edit dl rm
IO::WrapTie.3pm	14987	0444	edit dl rm
JSON::PP.3pm	50080	0444	edit dl rm
JSON::PP::Boolean.3pm	2667	0444	edit dl rm
JSON::Syck.3pm	8094	0444	edit dl rm
JSON::XS.3pm	89037	0444	edit dl rm
JSON::XS::Boolean.3pm	2857	0444	edit dl rm
lib::core::only.3pm	5647	0444	edit dl rm
local::lib.3pm	31390	0444	edit dl rm
LWP.3pm	28506	0444	edit dl rm
LWP::Authen::Ntlm.3pm	7489	0444	edit dl rm
LWP::ConnCache.3pm	9967	0444	edit dl rm
LWP::Debug.3pm	5608	0444	edit dl rm
LWP::MemberMixin.3pm	4821	0444	edit dl rm
LWP::Protocol.3pm	8350	0444	edit dl rm
LWP::Protocol::https.3pm	5684	0444	edit dl rm
LWP::RobotUA.3pm	9022	0444	edit dl rm
LWP::Simple.3pm	9016	0444	edit dl rm
LWP::UserAgent.3pm	48156	0444	edit dl rm
lwpcook.3pm	14838	0444	edit dl rm
lwptut.3pm	32441	0444	edit dl rm
Module::Build.3pm	44563	0444	edit dl rm
Module::Build::API.3pm	89267	0444	edit dl rm
Module::Build::Authoring.3pm	17363	0444	edit dl rm
Module::Build::Base.3pm	5157	0444	edit dl rm
Module::Build::Bundling.3pm	9999	0444	edit dl rm
Module::Build::Compat.3pm	10885	0444	edit dl rm
Module::Build::ConfigData.3pm	7388	0444	edit dl rm
Module::Build::Cookbook.3pm	25946	0444	edit dl rm
Module::Build::Notes.3pm	4690	0444	edit dl rm
Module::Build::Platform::aix.3pm	4472	0444	edit dl rm
Module::Build::Platform::cygwin.3pm	4505	0444	edit dl rm
Module::Build::Platform::darwin.3pm	4491	0444	edit dl rm
Module::Build::Platform::Default.3pm	4490	0444	edit dl rm
Module::Build::Platform::MacOS.3pm	5398	0444	edit dl rm
Module::Build::Platform::os2.3pm	4474	0444	edit dl rm
Module::Build::Platform::Unix.3pm	4481	0444	edit dl rm
Module::Build::Platform::VMS.3pm	7885	0444	edit dl rm
Module::Build::Platform::VOS.3pm	4477	0444	edit dl rm
Module::Build::Platform::Windows.3pm	4529	0444	edit dl rm
Module::Build::PPMMaker.3pm	4886	0444	edit dl rm
Mozilla::CA.3pm	3571	0444	edit dl rm
Net::CIDR::Lite.3pm	9562	0444	edit dl rm
Net::Cmd.3pm	11545	0444	edit dl rm
Net::Config.3pm	8100	0444	edit dl rm
Net::Domain.3pm	3835	0444	edit dl rm
Net::FTP.3pm	27341	0444	edit dl rm
Net::FTP::dataconn.3pm	3979	0444	edit dl rm
Net::HTTP.3pm	16375	0444	edit dl rm
Net::HTTP::NB.3pm	5394	0444	edit dl rm
Net::HTTPS.3pm	5438	0444	edit dl rm
Net::IP.3pm	27697	0444	edit dl rm
Net::libnetFAQ.3pm	14746	0444	edit dl rm
Net::Netrc.3pm	6729	0444	edit dl rm
Net::NNTP.3pm	23193	0444	edit dl rm
Net::POP3.3pm	12259	0444	edit dl rm
Net::SMTP.3pm	18880	0444	edit dl rm
Net::SSLeay.3pm	349350	0444	edit dl rm
Net::SSLeay::Handle.3pm	9127	0444	edit dl rm
Net::Time.3pm	4524	0444	edit dl rm
ok.3pm	2851	0444	edit dl rm
Parse::CPAN::Meta.3pm	10187	0444	edit dl rm
POD2::DE::local::lib.3pm	22879	0444	edit dl rm
POD2::PT_BR::local::lib.3pm	22762	0444	edit dl rm
Socket.3pm	34078	0444	edit dl rm
Sub::Identify.3pm	5087	0444	edit dl rm
SUPER.3pm	7394	0444	edit dl rm
Switch.3pm	19014	0444	edit dl rm
TAP::Base.3pm	3401	0444	edit dl rm
TAP::Formatter::Base.3pm	6233	0444	edit dl rm
TAP::Formatter::Color.3pm	3717	0444	edit dl rm
TAP::Formatter::Console.3pm	2722	0444	edit dl rm
TAP::Formatter::Console::ParallelSession.3pm	3065	0444	edit dl rm
TAP::Formatter::Console::Session.3pm	2832	0444	edit dl rm
TAP::Formatter::File.3pm	2693	0444	edit dl rm
TAP::Formatter::File::Session.3pm	2847	0444	edit dl rm
TAP::Formatter::Session.3pm	3603	0444	edit dl rm
TAP::Harness.3pm	21300	0444	edit dl rm
TAP::Harness::Beyond.3pm	19118	0444	edit dl rm
TAP::Harness::Env.3pm	5467	0444	edit dl rm
TAP::Object.3pm	4497	0444	edit dl rm
TAP::Parser.3pm	42210	0444	edit dl rm
TAP::Parser::Aggregator.3pm	8023	0444	edit dl rm
TAP::Parser::Grammar.3pm	8647	0444	edit dl rm
TAP::Parser::Iterator.3pm	4993	0444	edit dl rm
TAP::Parser::Iterator::Array.3pm	3771	0444	edit dl rm
TAP::Parser::Iterator::Process.3pm	4601	0444	edit dl rm
TAP::Parser::Iterator::Stream.3pm	3712	0444	edit dl rm
TAP::Parser::IteratorFactory.3pm	6904	0444	edit dl rm
TAP::Parser::Multiplexer.3pm	4646	0444	edit dl rm
TAP::Parser::Result.3pm	7512	0444	edit dl rm
TAP::Parser::Result::Bailout.3pm	3293	0444	edit dl rm
TAP::Parser::Result::Comment.3pm	3118	0444	edit dl rm
TAP::Parser::Result::Plan.3pm	4173	0444	edit dl rm
TAP::Parser::Result::Pragma.3pm	3073	0444	edit dl rm
TAP::Parser::Result::Test.3pm	7114	0444	edit dl rm
TAP::Parser::Result::Unknown.3pm	2973	0444	edit dl rm
TAP::Parser::Result::Version.3pm	3154	0444	edit dl rm
TAP::Parser::Result::YAML.3pm	3086	0444	edit dl rm
TAP::Parser::ResultFactory.3pm	5523	0444	edit dl rm
TAP::Parser::Scheduler.3pm	8113	0444	edit dl rm
TAP::Parser::Scheduler::Job.3pm	4301	0444	edit dl rm
TAP::Parser::Scheduler::Spinner.3pm	3346	0444	edit dl rm
TAP::Parser::Source.3pm	8170	0444	edit dl rm
TAP::Parser::SourceHandler.3pm	7559	0444	edit dl rm
TAP::Parser::SourceHandler::Executable.3pm	5297	0444	edit dl rm
TAP::Parser::SourceHandler::File.3pm	4567	0444	edit dl rm
TAP::Parser::SourceHandler::Handle.3pm	4425	0444	edit dl rm
TAP::Parser::SourceHandler::Perl.3pm	6262	0444	edit dl rm
TAP::Parser::SourceHandler::RawTAP.3pm	4434	0444	edit dl rm
TAP::Parser::YAMLish::Reader.3pm	3995	0444	edit dl rm
TAP::Parser::YAMLish::Writer.3pm	4879	0444	edit dl rm
Template.3pm	27909	0444	edit dl rm
Template::Base.3pm	8149	0444	edit dl rm
Template::Config.3pm	8687	0444	edit dl rm
Template::Constants.3pm	7815	0444	edit dl rm
Template::Context.3pm	26637	0444	edit dl rm
Template::Directive.3pm	4821	0444	edit dl rm
Template::Document.3pm	11829	0444	edit dl rm
Template::Exception.3pm	6763	0444	edit dl rm
Template::FAQ.3pm	14564	0444	edit dl rm
Template::Filters.3pm	9817	0444	edit dl rm
Template::Grammar.3pm	5039	0444	edit dl rm
Template::Iterator.3pm	11413	0444	edit dl rm
Template::Manual.3pm	6317	0444	edit dl rm
Template::Manual::Config.3pm	79504	0444	edit dl rm
Template::Manual::Credits.3pm	8246	0444	edit dl rm
Template::Manual::Directives.3pm	77293	0444	edit dl rm
Template::Manual::Filters.3pm	20810	0444	edit dl rm
Template::Manual::Internals.3pm	23433	0444	edit dl rm
Template::Manual::Intro.3pm	14092	0444	edit dl rm
Template::Manual::Plugins.3pm	13780	0444	edit dl rm
Template::Manual::Syntax.3pm	14549	0444	edit dl rm
Template::Manual::Variables.3pm	33110	0444	edit dl rm
Template::Manual::Views.3pm	25953	0444	edit dl rm
Template::Manual::VMethods.3pm	28195	0444	edit dl rm
Template::Modules.3pm	9827	0444	edit dl rm
Template::Namespace::Constants.3pm	6002	0444	edit dl rm
Template::Parser.3pm	9917	0444	edit dl rm
Template::Plugin.3pm	10937	0444	edit dl rm
Template::Plugin::Assert.3pm	5446	0444	edit dl rm
Template::Plugin::CGI.3pm	6188	0444	edit dl rm
Template::Plugin::Datafile.3pm	6601	0444	edit dl rm
Template::Plugin::Date.3pm	9538	0444	edit dl rm
Template::Plugin::Directory.3pm	11979	0444	edit dl rm
Template::Plugin::Dumper.3pm	6078	0444	edit dl rm
Template::Plugin::File.3pm	13009	0444	edit dl rm
Template::Plugin::Filter.3pm	12936	0444	edit dl rm
Template::Plugin::Format.3pm	4895	0444	edit dl rm
Template::Plugin::HTML.3pm	7823	0444	edit dl rm
Template::Plugin::Image.3pm	11950	0444	edit dl rm
Template::Plugin::Iterator.3pm	5061	0444	edit dl rm
Template::Plugin::Math.3pm	6623	0444	edit dl rm
Template::Plugin::Pod.3pm	4784	0444	edit dl rm
Template::Plugin::Procedural.3pm	5631	0444	edit dl rm
Template::Plugin::Scalar.3pm	5032	0444	edit dl rm
Template::Plugin::String.3pm	17263	0444	edit dl rm
Template::Plugin::Table.3pm	11145	0444	edit dl rm
Template::Plugin::URL.3pm	8080	0444	edit dl rm
Template::Plugin::View.3pm	5479	0444	edit dl rm
Template::Plugin::Wrap.3pm	6433	0444	edit dl rm
Template::Plugins.3pm	9733	0444	edit dl rm
Template::Provider.3pm	14678	0444	edit dl rm
Template::Service.3pm	14813	0444	edit dl rm
Template::Stash.3pm	11983	0444	edit dl rm
Template::Stash::Context.3pm	7130	0444	edit dl rm
Template::Stash::XS.3pm	6644	0444	edit dl rm
Template::Test.3pm	15524	0444	edit dl rm
Template::Toolkit.3pm	9227	0444	edit dl rm
Template::Tools.3pm	5001	0444	edit dl rm
Template::Tools::tpage.3pm	5806	0444	edit dl rm
Template::Tools::ttree.3pm	16567	0444	edit dl rm
Template::Tutorial.3pm	4566	0444	edit dl rm
Template::Tutorial::Datafile.3pm	19539	0444	edit dl rm
Template::Tutorial::Web.3pm	34118	0444	edit dl rm
Template::View.3pm	12618	0444	edit dl rm
Template::VMethods.3pm	4688	0444	edit dl rm
Term::ReadKey.3pm	13029	0444	edit dl rm
Test2.3pm	9556	0444	edit dl rm
Test2::API.3pm	30424	0444	edit dl rm
Test2::API::Breakage.3pm	4988	0444	edit dl rm
Test2::API::Context.3pm	17574	0444	edit dl rm
Test2::API::Instance.3pm	12404	0444	edit dl rm
Test2::API::Stack.3pm	6568	0444	edit dl rm
Test2::Event.3pm	9189	0444	edit dl rm
Test2::Event::Bail.3pm	3470	0444	edit dl rm
Test2::Event::Diag.3pm	3338	0444	edit dl rm
Test2::Event::Exception.3pm	3520	0444	edit dl rm
Test2::Event::Generic.3pm	7662	0444	edit dl rm
Test2::Event::Info.3pm	4261	0444	edit dl rm
Test2::Event::Note.3pm	3323	0444	edit dl rm
Test2::Event::Ok.3pm	4255	0444	edit dl rm
Test2::Event::Plan.3pm	3907	0444	edit dl rm
Test2::Event::Skip.3pm	3665	0444	edit dl rm
Test2::Event::Subtest.3pm	3573	0444	edit dl rm
Test2::Event::Waiting.3pm	3107	0444	edit dl rm
Test2::Formatter.3pm	5208	0444	edit dl rm
Test2::Formatter::TAP.3pm	9255	0444	edit dl rm
Test2::Hub.3pm	16755	0444	edit dl rm
Test2::Hub::Interceptor.3pm	2937	0444	edit dl rm
Test2::Hub::Interceptor::Terminator.3pm	2980	0444	edit dl rm
Test2::Hub::Subtest.3pm	3803	0444	edit dl rm
Test2::IPC.3pm	3324	0444	edit dl rm
Test2::IPC::Driver.3pm	9512	0444	edit dl rm
Test2::IPC::Driver::Files.3pm	3822	0444	edit dl rm
Test2::Transition.3pm	18406	0444	edit dl rm
Test2::Util.3pm	5123	0444	edit dl rm
Test2::Util::ExternalMeta.3pm	5594	0444	edit dl rm
Test2::Util::HashBase.3pm	7463	0444	edit dl rm
Test2::Util::Trace.3pm	5577	0444	edit dl rm
Test::Builder.3pm	26915	0444	edit dl rm
Test::Builder::Formatter.3pm	3656	0444	edit dl rm
Test::Builder::IO::Scalar.3pm	9740	0444	edit dl rm
Test::Builder::Module.3pm	5567	0444	edit dl rm
Test::Builder::Tester.3pm	11550	0444	edit dl rm
Test::Builder::Tester::Color.3pm	3131	0444	edit dl rm
Test::Builder::TodoDiag.3pm	3129	0444	edit dl rm
Test::Fatal.3pm	9303	0444	edit dl rm
Test::HACKING.3pm	9253	0444	edit dl rm
Test::Harness.3pm	11028	0444	edit dl rm
Test::LeakTrace.3pm	10022	0444	edit dl rm
Test::LeakTrace::JA.3pm	12328	0444	edit dl rm
Test::LeakTrace::Script.3pm	5140	0444	edit dl rm
Test::MockModule.3pm	10818	0444	edit dl rm
Test::More.3pm	43215	0444	edit dl rm
Test::More::UTF8.3pm	3602	0444	edit dl rm
Test::RequiresInternet.3pm	3944	0444	edit dl rm
Test::Simple.3pm	9119	0444	edit dl rm
Test::Tester.3pm	15781	0444	edit dl rm
Test::Tester::Capture.3pm	2902	0444	edit dl rm
Test::Tester::CaptureRunner.3pm	2673	0444	edit dl rm
Test::Tutorial.3pm	24261	0444	edit dl rm
Test::use::ok.3pm	3841	0444	edit dl rm
Test::Warnings.3pm	14231	0444	edit dl rm
Text::Glob.3pm	6106	0444	edit dl rm
Text::Template.3pm	65499	0444	edit dl rm
Text::Template::Preprocess.3pm	6270	0444	edit dl rm
Time::Zone.3pm	3413	0444	edit dl rm
TimeDate.3pm	2397	0444	edit dl rm
Try::Tiny.3pm	20343	0444	edit dl rm
Types::Serialiser.3pm	11473	0444	edit dl rm
Types::Serialiser::Error.3pm	2705	0444	edit dl rm
version.3pm	13937	0444	edit dl rm
version::Internals.3pm	30287	0444	edit dl rm
WWW::Mechanize.3pm	68196	0444	edit dl rm
WWW::Mechanize::Cookbook.3pm	7159	0444	edit dl rm
WWW::Mechanize::Examples.3pm	22490	0444	edit dl rm
WWW::Mechanize::FAQ.3pm	24359	0444	edit dl rm
WWW::Mechanize::Image.3pm	6490	0444	edit dl rm
WWW::Mechanize::Link.3pm	6518	0444	edit dl rm
XML::NamespaceSupport.3pm	13052	0444	edit dl rm
XML::Parser.3pm	26296	0444	edit dl rm
XML::Parser::Expat.3pm	26799	0444	edit dl rm
XML::Parser::Style::Debug.3pm	4408	0444	edit dl rm
XML::Parser::Style::Objects.3pm	4888	0444	edit dl rm
XML::Parser::Style::Stream.3pm	5925	0444	edit dl rm
XML::Parser::Style::Subs.3pm	4863	0444	edit dl rm
XML::Parser::Style::Tree.3pm	5529	0444	edit dl rm
XML::SAX.3pm	9229	0444	edit dl rm
XML::SAX::Base.3pm	13704	0444	edit dl rm
XML::SAX::BuildSAXBase.3pm	13700	0444	edit dl rm
XML::SAX::DocumentLocator.3pm	5239	0444	edit dl rm
XML::SAX::Exception.3pm	5622	0444	edit dl rm
XML::SAX::Expat.3pm	6404	0444	edit dl rm
XML::SAX::Intro.3pm	20220	0444	edit dl rm
XML::SAX::ParserFactory.3pm	7919	0444	edit dl rm
XML::SAX::PurePerl.3pm	6172	0444	edit dl rm
XML::SAX::PurePerl::Reader.3pm	4103	0444	edit dl rm
XML::Simple.3pm	65589	0444	edit dl rm
XML::Simple::FAQ.3pm	27223	0444	edit dl rm
YAML.3pm	29980	0444	edit dl rm
YAML::Any.3pm	7487	0444	edit dl rm
YAML::Dumper.3pm	4776	0444	edit dl rm
YAML::Dumper::Base.3pm	4642	0444	edit dl rm
YAML::Error.3pm	4681	0444	edit dl rm
YAML::Loader.3pm	4766	0444	edit dl rm
YAML::Loader::Base.3pm	4642	0444	edit dl rm
YAML::Marshall.3pm	4640	0444	edit dl rm
YAML::Node.3pm	6743	0444	edit dl rm
YAML::Syck.3pm	10806	0444	edit dl rm
YAML::Tag.3pm	4499	0444	edit dl rm
YAML::Types.3pm	4716	0444	edit dl rm

Edit: /usr/local/share/man/man3/HTML::Tree::AboutObjects.3pm (37918B)

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.\" ========================================================================
.\"
.IX Title "HTML::Tree::AboutObjects 3"
.TH HTML::Tree::AboutObjects 3 "2016-10-25" "perl v5.16.3" "User Contributed Perl Documentation"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
.if n .ad l
.nh
.SH "NAME"
HTML::Tree::AboutObjects \-\- article: "User's View of Object\-Oriented Modules"
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 1
\&  # This an article, not a module.
.Ve
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
The following article by Sean M. Burke first appeared in \fIThe Perl
Journal\fR #17 and is copyright 2000 The Perl Journal. It appears
courtesy of Jon Orwant and The Perl Journal.  This document may be
distributed under the same terms as Perl itself.
.SH "A User's View of Object-Oriented Modules"
.IX Header "A User's View of Object-Oriented Modules"
\&\-\- Sean M. Burke
.PP
The first time that most Perl programmers run into object-oriented
programming when they need to use a module whose interface is
object-oriented.  This is often a mystifying experience, since talk of
\&\*(L"methods\*(R" and \*(L"constructors\*(R" is unintelligible to programmers who
thought that functions and variables was all there was to worry about.
.PP
Articles and books that explain object-oriented programming (\s-1OOP\s0), do so
in terms of how to program that way.  That's understandable, and if you
learn to write object-oriented code of your own, you'd find it easy to
use object-oriented code that others write.  But this approach is the
\&\fIlong\fR way around for people whose immediate goal is just to use
existing object-oriented modules, but who don't yet want to know all the
gory details of having to write such modules for themselves.
.PP
This article is for those programmers \*(-- programmers who want to know
about objects from the perspective of using object-oriented modules.
.SS "Modules and Their Functional Interfaces"
.IX Subsection "Modules and Their Functional Interfaces"
Modules are the main way that Perl provides for bundling up code for
later use by yourself or others.  As I'm sure you can't help noticing
from reading
\&\fIThe Perl Journal\fR, \s-1CPAN \s0(the Comprehensive Perl Archive
Network) is the repository for modules (or groups of modules) that
others have written, to do anything from composing music to accessing
Web pages.  A good deal of those modules even come with every
installation of Perl.
.PP
One module that you may have used before, and which is fairly typical in
its interface, is Text::Wrap.  It comes with Perl, so you don't even
need to install it from \s-1CPAN. \s0 You use it in a program of yours, by
having your program code say early on:
.PP
.Vb 1
\&  use Text::Wrap;
.Ve
.PP
and after that, you can access a function called \f(CW\*(C`wrap\*(C'\fR, which inserts
line-breaks in text that you feed it, so that the text will be wrapped to
seventy-two (or however many) columns.
.PP
The way this \f(CW\*(C`use Text::Wrap\*(C'\fR business works is that the module
Text::Wrap exists as a file \*(L"Text/Wrap.pm\*(R" somewhere in one of your
library directories.  That file contains Perl code...
.Sp
.RS 4
Footnote: And mixed in with the Perl code, there's documentation, which
is what you read with \*(L"perldoc Text::Wrap\*(R".  The perldoc program simply
ignores the code and formats the documentation text, whereas \*(L"use
Text::Wrap\*(R" loads and runs the code while ignoring the documentation.
.RE
.PP
\&...which, among other things, defines a function called \f(CW\*(C`Text::Wrap::wrap\*(C'\fR,
and then \f(CW\*(C`exports\*(C'\fR that function, which means that when you say \f(CW\*(C`wrap\*(C'\fR
after having said \*(L"use Text::Wrap\*(R", you'll be actually calling the
\&\f(CW\*(C`Text::Wrap::wrap\*(C'\fR function.  Some modules don't export their
functions, so you have to call them by their full name, like
\&\f(CW\*(C`Text::Wrap::wrap(...parameters...)\*(C'\fR.
.PP
Regardless of whether the typical module exports the functions it
provides, a module is basically just a container for chunks of code that
do useful things.  The way the module allows for you to interact with
it, is its \fIinterface\fR.  And when, like with Text::Wrap, its interface
consists of functions, the module is said to have a \fBfunctional
interface\fR.
.Sp
.RS 4
Footnote: the term \*(L"function\*(R" (and therefore "function\fIal\fR") has
various senses.  I'm using the term here in its broadest sense, to
refer to routines \*(-- bits of code that are called by some name and
which take parameters and return some value.
.RE
.PP
Using modules with functional interfaces is straightforward \*(-- instead
of defining your own \*(L"wrap\*(R" function with \f(CW\*(C`sub wrap { ... }\*(C'\fR, you
entrust \*(L"use Text::Wrap\*(R" to do that for you, along with whatever other
functions its defines and exports, according to the module's
documentation.  Without too much bother, you can even write your own
modules to contain your frequently used functions; I suggest having a look at
the \f(CW\*(C`perlmod\*(C'\fR man page for more leads on doing this.
.SS "Modules with Object-Oriented Interfaces"
.IX Subsection "Modules with Object-Oriented Interfaces"
So suppose that one day you want to write a program that will automate
the process of \f(CW\*(C`ftp\*(C'\fRing a bunch of files from one server down to your
local machine, and then off to another server.
.PP
A quick browse through search.cpan.org turns up the module \*(L"Net::FTP\*(R",
which you can download and install it using normal installation
instructions (unless your sysadmin has already installed it, as many
have).
.PP
Like Text::Wrap or any other module with a familiarly functional
interface, you start off using Net::FTP in your program by saying:
.PP
.Vb 1
\&  use Net::FTP;
.Ve
.PP
However, that's where the similarity ends.  The first hint of
difference is that the documentation for Net::FTP refers to it as a
\&\fBclass\fR.  A class is a kind of module, but one that has an
object-oriented interface.
.PP
Whereas modules like Text::Wrap
provide bits of useful code as \fIfunctions\fR, to be called like
\&\f(CW\*(C`function(...parameters...)\*(C'\fR or like
\&\f(CW\*(C`PackageName::function(...parameters...)\*(C'\fR, Net::FTP and other modules
with object-oriented interfaces provide \fBmethods\fR.  Methods are sort of
like functions in that they have a name and parameters; but methods
look different, and are different, because you have to call them with a
syntax that has a class name or an object as a special argument.  I'll
explain the syntax for method calls, and then later explain what they
all mean.
.PP
Some methods are meant to be called as \fBclass methods\fR, with the class
name (same as the module name) as a special argument.  Class methods
look like this:
.PP
.Vb 3
\&  ClassName\->methodname(parameter1, parameter2, ...)
\&  ClassName\->methodname()   # if no parameters
\&  ClassName\->methodname     # same as above
.Ve
.PP
which you will sometimes see written:
.PP
.Vb 2
\&  methodname ClassName (parameter1, parameter2, ...)
\&  methodname ClassName      # if no parameters
.Ve
.PP
Basically all class methods are for making new objects, and methods that
make objects are called "\fBconstructors\fR\*(L" (and the process of making them
is called \*(R"constructing\*(L" or \*(R"instantiating\*(L").  Constructor methods
typically have the name \*(R"new\*(L", or something including \*(R"new\*(L"
(\*(R"new_from_file\*(L", etc.); but they can conceivably be named
anything \*(-- \s-1DBI\s0's constructor method is named \*(R"connect", for example.
.PP
The object that a constructor method returns is
typically captured in a scalar variable:
.PP
.Vb 1
\&  $object = ClassName\->new(param1, param2...);
.Ve
.PP
Once you have an object (more later on exactly what that is), you can
use the other kind of method call syntax, the syntax for \fBobject method\fR
calls.  Calling object methods is just like class methods, except
that instead of the ClassName as the special argument,
you use an expression that yeilds an \*(L"object\*(R".  Usually this is
just a scalar variable that you earlier captured the
output of the constructor in.  Object method calls look like this:
.PP
.Vb 3
\&  $object\->methodname(parameter1, parameter2, ...);
\&  $object\->methodname()   # if no parameters
\&  $object\->methodname     # same as above
.Ve
.PP
which is occasionally written as:
.PP
.Vb 2
\&  methodname $object (parameter1, parameter2, ...)
\&  methodname $object      # if no parameters
.Ve
.PP
Examples of method calls are:
.PP
.Vb 10
\&  my $session1 = Net::FTP\->new("ftp.myhost.com");
\&    # Calls a class method "new", from class Net::FTP,
\&    #  with the single parameter "ftp.myhost.com",
\&    #  and saves the return value (which is, as usual,
\&    #  an object), in $session1.
\&    # Could also be written:
\&    #  new Net::FTP(\*(Aqftp.myhost.com\*(Aq)
\&  $session1\->login("sburke","aoeuaoeu")
\&    || die "failed to login!\en";
\&     # calling the object method "login"
\&  print "Dir:\en", $session1\->dir(), "\en";
\&  $session1\->quit;
\&    # same as $session1\->quit()
\&  print "Done\en";
\&  exit;
.Ve
.PP
Incidentally, I suggest always using the syntaxes with parentheses and
\&\*(L"\->\*(R" in them,
.Sp
.RS 4
Footnote: the character-pair \*(L"\->\*(R" is supposed to look like an
arrow, not \*(L"negative greater-than\*(R"!
.RE
.PP
and avoiding the syntaxes that start out \*(L"methodname \f(CW$object\fR\*(R" or
\&\*(L"methodname ModuleName\*(R".  When everything's going right, they all mean
the same thing as the \*(L"\->\*(R" variants, but the syntax with \*(L"\->\*(R" is more
visually distinct from function calls, as well as being immune to some
kinds of rare but puzzling ambiguities that can arise when you're trying
to call methods that have the same name as subroutines you've defined.
.PP
But, syntactic alternatives aside, all this talk of constructing objects
and object methods begs the question \*(-- what \fIis\fR an object?  There are
several angles to this question that the rest of this article will
answer in turn: what can you do with objects?  what's in an object?
what's an object value?  and why do some modules use objects at all?
.SS "What Can You Do with Objects?"
.IX Subsection "What Can You Do with Objects?"
You've seen that you can make objects, and call object methods with
them.  But what are object methods for?  The answer depends on the class:
.PP
A Net::FTP object represents a session between your computer and an \s-1FTP\s0
server.  So the methods you call on a Net::FTP object are for doing
whatever you'd need to do across an \s-1FTP\s0 connection.  You make the
session and log in:
.PP
.Vb 5
\&  my $session = Net::FTP\->new(\*(Aqftp.aol.com\*(Aq);
\&  die "Couldn\*(Aqt connect!" unless defined $session;
\&    # The class method call to "new" will return
\&    # the new object if it goes OK, otherwise it
\&    # will return undef.
\&    
\&  $session\->login(\*(Aqsburke\*(Aq, \*(Aqp@ssw3rD\*(Aq)
\&   || die "Did I change my password again?";
\&    # The object method "login" will give a true
\&    # return value if actually logs in, otherwise
\&    # it\*(Aqll return false.
.Ve
.PP
You can use the session object to change directory on that session:
.PP
.Vb 3
\&  $session\->cwd("/home/sburke/public_html")
\&     || die "Hey, that was REALLY supposed to work!";
\&   # if the cwd fails, it\*(Aqll return false
.Ve
.PP
\&...get files from the machine at the other end of the session...
.PP
.Vb 5
\&  foreach my $f (\*(Aqlog_report_ua.txt\*(Aq, \*(Aqlog_report_dom.txt\*(Aq,
\&                 \*(Aqlog_report_browsers.txt\*(Aq)
\&  {
\&    $session\->get($f) || warn "Getting $f failed!"
\&  };
.Ve
.PP
\&...and plenty else, ending finally with closing the connection:
.PP
.Vb 1
\&  $session\->quit();
.Ve
.PP
In short, object methods are for doing things related to (or with)
whatever the object represents.  For \s-1FTP\s0 sessions, it's about sending
commands to the server at the other end of the connection, and that's
about it \*(-- there, methods are for doing something to the world outside
the object, and the objects is just something that specifies what bit
of the world (well, what \s-1FTP\s0 session) to act upon.
.PP
With most other classes, however, the object itself stores some kind of
information, and it typically makes no sense to do things with such an
object without considering the data that's in the object.
.SS "What's \fIin\fP an Object?"
.IX Subsection "What's in an Object?"
An object is (with rare exceptions) a data structure containing a
bunch of attributes, each of which has a value, as well as a name
that you use when you
read or set the attribute's value.  Some of the object's attributes are
private, meaning you'll never see them documented because they're not
for you to read or write; but most of the object's documented attributes
are at least readable, and usually writeable, by you.  Net::FTP objects
are a bit thin on attributes, so we'll use objects from the class
Business::US_Amort for this example.  Business::US_Amort is a very
simple class (available from \s-1CPAN\s0) that I wrote for making calculations
to do with loans (specifically, amortization, using US-style
algorithms).
.PP
An object of the class Business::US_Amort represents a loan with
particular parameters, i.e., attributes.  The most basic attributes of a
\&\*(L"loan object\*(R" are its interest rate, its principal (how much money it's
for), and it's term (how long it'll take to repay).  You need to set
these attributes before anything else can be done with the object.  The
way to get at those attributes for loan objects is just like the
way to get at attributes for any class's objects: through accessors.
An \fBaccessor\fR is simply any method that accesses (whether reading or
writing, \s-1AKA\s0 getting or putting) some attribute in the given object.
Moreover, accessors are the \fBonly\fR way that you can change
an object's attributes.  (If a module's documentation wants you to
know about any other way, it'll tell you.)
.PP
Usually, for simplicity's sake, an accessor is named after the attribute
it reads or writes.  With Business::US_Amort objects, the accessors you
need to use first are \f(CW\*(C`principal\*(C'\fR, \f(CW\*(C`interest_rate\*(C'\fR, and \f(CW\*(C`term\*(C'\fR.
Then, with at least those attributes set, you can call the \f(CW\*(C`run\*(C'\fR method
to figure out several things about the loan.  Then you can call various
accessors, like \f(CW\*(C`total_paid_toward_interest\*(C'\fR, to read the results:
.PP
.Vb 6
\&  use Business::US_Amort;
\&  my $loan = Business::US_Amort\->new;
\&  # Set the necessary attributes:
\&  $loan\->principal(123654);
\&  $loan\->interest_rate(9.25);
\&  $loan\->term(20); # twenty years
\&
\&  # NOW we know enough to calculate:
\&  $loan\->run;
\&  
\&  # And see what came of that:
\&  print
\&    "Total paid toward interest: A WHOPPING ",
\&    $loan\->total_paid_interest, "!!\en";
.Ve
.PP
This illustrates a convention that's common with accessors: calling the
accessor with no arguments (as with \f(CW$loan\fR\->total_paid_interest) usually
means to read the value of that attribute, but providing a value (as
with \f(CW$loan\fR\->term(20)) means you want that attribute to be set to that
value.  This stands to reason: why would you be providing a value, if
not to set the attribute to that value?
.PP
Although a loan's term, principal, and interest rates are all single
numeric values, an objects values can any kind of scalar, or an array,
or even a hash.  Moreover, an attribute's value(s) can be objects
themselves.  For example, consider \s-1MIDI\s0 files (as I wrote about in
TPJ#13): a \s-1MIDI\s0 file usually consists of several tracks.  A \s-1MIDI\s0 file is
complex enough to merit being an object with attributes like its overall
tempo, the file-format variant it's in, and the list of instrument
tracks in the file.  But tracks themselves are complex enough to be
objects too, with attributes like their track-type, a list of \s-1MIDI\s0
commands if they're a \s-1MIDI\s0 track, or raw data if they're not.  So I
ended up writing the \s-1MIDI\s0 modules so that the \*(L"tracks\*(R" attribute of a
MIDI::Opus object is an array of objects from the class MIDI::Track.
This may seem like a runaround \*(-- you ask what's in one object, and get
\&\fIanother\fR object, or several!  But in this case, it exactly reflects
what the module is for \*(-- \s-1MIDI\s0 files contain \s-1MIDI\s0 tracks, which then
contain data.
.SS "What is an Object Value?"
.IX Subsection "What is an Object Value?"
When you call a constructor like Net::FTP\->new(\fIhostname\fR), you get
back an object value, a value you can later use, in combination with a
method name, to call object methods.
.PP
Now, so far we've been pretending, in the above examples, that the
variables \f(CW$session\fR or \f(CW$loan\fR \fIare\fR the objects you're dealing with.
This idea is innocuous up to a point, but it's really a misconception
that will, at best, limit you in what you know how to do.  The reality
is not that the variables \f(CW$session\fR or \f(CW$query\fR are objects; it's a little
more indirect \*(-- they \fIhold\fR values that symbolize objects.  The kind of
value that \f(CW$session\fR or \f(CW$query\fR hold is what I'm calling an object value.
.PP
To understand what kind of value this is, first think about the other
kinds of scalar values you know about: The first two scalar values you
probably ever ran into in Perl are \fBnumbers\fR and \fBstrings\fR, which you
learned (or just assumed) will usually turn into each other on demand;
that is, the three-character string \*(L"2.5\*(R" can become the quantity two
and a half, and vice versa.  Then, especially if you started using
\&\f(CW\*(C`perl \-w\*(C'\fR early on, you learned about the \fBundefined value\fR, which can
turn into 0 if you treat it as a number, or the empty-string if you
treat it as a string.
.Sp
.RS 4
Footnote: You may \fIalso\fR have been learning about references, in which
case you're ready to hear that object values are just a kind of
reference, except that they reflect the class that created thing they point
to, instead of merely being a plain old array reference, hash reference,
etc.  \fIIf\fR this makes makes sense to you, and you want to know more
about how objects are implemented in Perl, have a look at the
\&\f(CW\*(C`perltoot\*(C'\fR man page.
.RE
.PP
And now you're learning about \fBobject values\fR.  An object value is a
value that points to a data structure somewhere in memory, which is
where all the attributes for this object are stored.  That data
structure as a whole belongs to a class (probably the one you named in
the constructor method, like ClassName\->new), so that the object value
can be used as part of object method calls.
.PP
If you want to actually \fIsee\fR what an object value is, you might try
just saying \*(L"print \f(CW$object\fR\*(R".  That'll get you something like this:
.PP
.Vb 1
\&  Net::FTP=GLOB(0x20154240)
.Ve
.PP
or
.PP
.Vb 1
\&  Business::US_Amort=HASH(0x15424020)
.Ve
.PP
That's not very helpful if you wanted to really get at the object's
insides, but that's because the object value is only a symbol for the
object.  This may all sound very abstruse and metaphysical, so a
real-world allegory might be very helpful:
.Sp
.RS 4
You get an advertisement in the mail saying that you have been
(im)personally selected to have the rare privilege of applying for a
credit card.  For whatever reason, \fIthis\fR offer sounds good to you, so you
fill out the form and mail it back to the credit card company.  They
gleefully approve the application and create your account, and send you
a card with a number on it.
.Sp
Now, you can do things with the number on that card \*(-- clerks at stores
can ring up things you want to buy, and charge your account by keying in
the number on the card.  You can pay for things you order online by
punching in the card number as part of your online order.  You can pay
off part of the account by sending the credit card people some of your
money (well, a check) with some note (usually the pre-printed slip)
that has the card number for the account you want to pay toward.  And you
should be able to call the credit card company's computer and ask it
things about the card, like its balance, its credit limit, its \s-1APR,\s0 and
maybe an itemization of recent purchases ad payments.
.Sp
Now, what you're \fIreally\fR doing is manipulating a credit card
\&\fIaccount\fR, a completely abstract entity with some data attached to it
(balance, \s-1APR,\s0 etc).  But for ease of access, you have a credit card
\&\fInumber\fR that is a symbol for that account.  Now, that symbol is just a
bunch of digits, and the number is effectively meaningless and useless
in and of itself \*(-- but in the appropriate context, it's understood to
\&\fImean\fR the credit card account you're accessing.
.RE
.PP
This is exactly the relationship between objects and object values, and
from this analogy, several facts about object values are a bit more
explicable:
.PP
* An object value does nothing in and of itself, but it's useful when
you use it in the context of an \f(CW$object\fR\->method call, the same way that
a card number is useful in the context of some operation dealing with a
card account.
.PP
Moreover, several copies of the same object value all refer to the same
object, the same way that making several copies of your card number
won't change the fact that they all still refer to the same single
account (this is true whether you're \*(L"copying\*(R" the number by just
writing it down on different slips of paper, or whether you go to the
trouble of forging exact replicas of your own plastic credit card).  That's
why this:
.PP
.Vb 2
\&  $x = Net::FTP\->new("ftp.aol.com");
\&  $x\->login("sburke", "aoeuaoeu");
.Ve
.PP
does the same thing as this:
.PP
.Vb 4
\&  $x = Net::FTP\->new("ftp.aol.com");
\&  $y = $x;
\&  $z = $y;
\&  $z\->login("sburke", "aoeuaoeu");
.Ve
.PP
That is, \f(CW$z\fR and \f(CW$y\fR and \f(CW$x\fR are three different \fIslots\fR for values,
but what's in those slots are all object values pointing to the same
object \*(-- you don't have three different \s-1FTP\s0 connections, just three
variables with values pointing to the some single \s-1FTP\s0 connection.
.PP
* You can't tell much of anything about the object just by looking at
the object value, any more than you can see your credit account balance
by holding the plastic card up to the light, or by adding up the digits
in your credit card number.
.PP
* You can't just make up your own object values and have them work \*(--
they can come only from constructor methods of the appropriate class.
Similarly, you get a credit card number \fIonly\fR by having a bank approve
your application for a credit card account \*(-- at which point \fIthey\fR
let \fIyou\fR know what the number of your new card is.
.PP
Now, there's even more to the fact that you can't just make up your own
object value: even though you can print an object value and get a string
like \*(L"Net::FTP=GLOB(0x20154240)\*(R", that string is just a
\&\fIrepresentation\fR of an object value.
.PP
Internally, an object value has a basically different type from a
string, or a number, or the undefined value \*(-- if \f(CW$x\fR holds a real
string, then that value's slot in memory says "this is a value of type
\&\fIstring\fR, and its characters are...\*(L", whereas if it's an object value,
the value's slot in memory says, \*(R"this is a value of type \fIreference\fR,
and the location in memory that it points to is..." (and by looking at
what's at that location, Perl can tell the class of what's there).
.PP
Perl programmers typically don't have to think about all these details
of Perl's internals.  Many other languages force you to be more
conscious of the differences between all of these (and also between
types of numbers, which are stored differently depending on their size
and whether they have fractional parts).  But Perl does its best to
hide the different types of scalars from you \*(-- it turns numbers into
strings and back as needed, and takes the string or number
representation of undef or of object values as needed.  However, you
can't go from a string representation of an object value, back to an
object value.  And that's why this doesn't work:
.PP
.Vb 9
\&   $x = Net::FTP\->new(\*(Aqftp.aol.com\*(Aq);
\&   $y = Net::FTP\->new(\*(Aqftp.netcom.com\*(Aq);
\&   $z = Net::FTP\->new(\*(Aqftp.qualcomm.com\*(Aq);
\&   $all = join(\*(Aq \*(Aq, $x,$y,$z);           # !!!
\&  ...later...
\&   ($aol, $netcom, $qualcomm) = split(\*(Aq \*(Aq, $all);  # !!!
\&   $aol\->login("sburke", "aoeuaoeu");
\&   $netcom\->login("sburke", "qjkxqjkx");
\&   $qualcomm\->login("smb", "dhtndhtn");
.Ve
.PP
This fails because \f(CW$aol\fR ends up holding merely the \fBstring representation\fR
of the object value from \f(CW$x\fR, not the object value itself \*(-- when
\&\f(CW\*(C`join\*(C'\fR tried to join the characters of the \*(L"strings\*(R" \f(CW$x\fR, \f(CW$y\fR, and \f(CW$z\fR,
Perl saw that they weren't strings at all, so it gave \f(CW\*(C`join\*(C'\fR their
string representations.
.PP
Unfortunately, this distinction between object values and their string
representations doesn't really fit into the analogy of credit card
numbers, because credit card numbers really \fIare\fR numbers \*(-- even
thought they don't express any meaningful quantity, if you stored them
in a database as a quantity (as opposed to just an \s-1ASCII\s0 string),
that wouldn't stop them from being valid as credit card numbers.
.PP
This may seem rather academic, but there's there's two common mistakes
programmers new to objects often make, which make sense only in terms of
the distinction between object values and their string representations:
.PP
The first common error involves forgetting (or never having known in the
first place) that when you go to use a value as a hash key, Perl uses
the string representation of that value.  When you want to use the
numeric value two and a half as a key, Perl turns it into the
three-character string \*(L"2.5\*(R".  But if you then want to use that string
as a number, Perl will treat it as meaning two and a half, so you're
usually none the wiser that Perl converted the number to a string and
back.  But recall that Perl can't turn strings back into objects \*(-- so
if you tried to use a Net::FTP object value as a hash key, Perl actually
used its string representation, like \*(L"Net::FTP=GLOB(0x20154240)\*(R", but
that string is unusable as an object value.  (Incidentally, there's
a module Tie::RefHash that implements hashes that \fIdo\fR let you use
real object-values as keys.)
.PP
The second common error with object values is in
trying to save an object value to disk (whether printing it to a
file, or storing it in a conventional database file).  All you'll get is the
string, which will be useless.
.PP
When you want to save an object and restore it later, you may find that
the object's class already provides a method specifically for this.  For
example, MIDI::Opus provides methods for writing an object to disk as a
standard \s-1MIDI\s0 file.  The file can later be read back into memory by
a MIDI::Opus constructor method, which will return a new MIDI::Opus
object representing whatever file you tell it to read into memory.
Similar methods are available with, for example, classes that
manipulate graphic images and can save them to files, which can be read
back later.
.PP
But some classes, like Business::US_Amort, provide no such methods for
storing an object in a file.  When this is the case, you can try
using any of the Data::Dumper, Storable, or FreezeThaw modules.  Using
these will be unproblematic for objects of most classes, but it may run
into limitations with others.  For example, a Business::US_Amort
object can be turned into a string with Data::Dumper, and that string
written to a file.  When it's restored later, its attributes will be
accessible as normal.  But in the unlikely case that the loan object was
saved in mid-calculation, the calculation may not be resumable.  This is
because of the way that that \fIparticular\fR class does its calculations,
but similar limitations may occur with objects from other classses.
.PP
But often, even \fIwanting\fR to save an object is basically wrong \*(-- what would
saving an ftp \fIsession\fR even mean?  Saving the hostname, username, and
password?  current directory on both machines?  the local \s-1TCP/IP\s0 port
number?  In the case of \*(L"saving\*(R" a Net::FTP object, you're better off
just saving whatever details you actually need for your own purposes,
so that you can make a new object later and just set those values for it.
.SS "So Why Do Some Modules Use Objects?"
.IX Subsection "So Why Do Some Modules Use Objects?"
All these details of using objects are definitely enough to make you
wonder \*(-- is it worth the bother?  If you're a module author, writing
your module with an object-oriented interface restricts the audience of
potential users to those who understand the basic concepts of objects
and object values, as well as Perl's syntax for calling methods.  Why
complicate things by having an object-oriented interface?
.PP
A somewhat esoteric answer is that a module has an object-oriented
interface because the module's insides are written in an
object-oriented style.  This article is about the basics of
object-oriented \fIinterfaces\fR, and it'd be going far afield to explain
what object-oriented \fIdesign\fR is.  But the short story is that
object-oriented design is just one way of attacking messy problems.
It's a way that many programmers find very helpful (and which others
happen to find to be far more of a hassle than it's worth,
incidentally), and it just happens to show up for you, the module user,
as merely the style of interface.
.PP
But a simpler answer is that a functional interface is sometimes a
hindrance, because it limits the number of things you can do at once \*(--
limiting it, in fact, to one.  For many problems that some modules are
meant to solve, doing without an object-oriented interface would be like
wishing that Perl didn't use filehandles.  The ideas are rather simpler
\&\*(-- just imagine that Perl let you access files, but \fIonly\fR one at a
time, with code like:
.PP
.Vb 5
\&  open("foo.txt") || die "Can\*(Aqt open foo.txt: $!";
\&  while(readline) {
\&    print $_ if /bar/;
\&  }
\&  close;
.Ve
.PP
That hypothetical kind of Perl would be simpler, by doing without
filehandles.  But you'd be out of luck if you wanted to read from
one file while reading from another, or read from two and print to a
third.
.PP
In the same way, a functional \s-1FTP\s0 module would be fine for just
uploading files to one server at a time, but it wouldn't allow you to
easily write programs that make need to use \fIseveral\fR simultaneous
sessions (like \*(L"look at server A and server B, and if A has a file
called X.dat, then download it locally and then upload it to server B \*(--
except if B has a file called Y.dat, in which case do it the other way
around\*(R").
.PP
Some kinds of problems that modules solve just lend themselves to an
object-oriented interface.  For those kinds of tasks, a functional
interface would be more familiar, but less powerful.  Learning to use
object-oriented modules' interfaces does require becoming comfortable
with the concepts from this article.  But in the end it will allow you
to use a broader range of modules and, with them, to write programs
that can do more.
.PP
\&\fB[end body of article]\fR
.SS "[Author Credit]"
.IX Subsection "[Author Credit]"
Sean M. Burke has contributed several modules to \s-1CPAN,\s0 about half of
them object-oriented.
.PP
[The next section should be in a greybox:]
.SS "The Gory Details"
.IX Subsection "The Gory Details"
For sake of clarity of explanation, I had to oversimplify some of the
facts about objects.  Here's a few of the gorier details:
.PP
* Every example I gave of a constructor was a class method.  But object
methods can be constructors, too, if the class was written to work that
way: \f(CW$new\fR = \f(CW$old\fR\->copy, \f(CW$node_y\fR = \f(CW$node_x\fR\->new_subnode, or the like.
.PP
* I've given the impression that there's two kinds of methods: object
methods and class methods.  In fact, the same method can be both,
because it's not the kind of method it is, but the kind of calls it's
written to accept \*(-- calls that pass an object, or calls that pass a
class-name.
.PP
* The term \*(L"object value\*(R" isn't something you'll find used much anywhere
else.  It's just my shorthand for what would properly be called an
\&\*(L"object reference\*(R" or \*(L"reference to a blessed item\*(R".  In fact, people
usually say \*(L"object\*(R" when they properly mean a reference to that object.
.PP
* I mentioned creating objects with \fIcon\fRstructors, but I didn't
mention destroying them with \fIde\fRstructor \*(-- a destructor is a kind of
method that you call to tidy up the object once you're done with it, and
want it to neatly go away (close connections, delete temporary files,
free up memory, etc).  But because of the way Perl handles memory,
most modules won't require the user to know about destructors.
.PP
* I said that class method syntax has to have the class name, as in
\&\f(CW$session\fR = \fBNet::FTP\fR\->new($host).  Actually, you can instead use any
expression that returns a class name: \f(CW$ftp_class\fR = 'Net::FTP'; \f(CW$session\fR
= \fB\f(CB$ftp_class\fB\fR\->new($host).  Moreover, instead of the method name for
object\- or class-method calls, you can use a scalar holding the method
name: \f(CW$foo\fR\->\fB\f(CB$method\fB\fR($host).  But, in practice, these syntaxes are
rarely useful.
.PP
And finally, to learn about objects from the perspective of writing
your own classes, see the \f(CW\*(C`perltoot\*(C'\fR documentation,
or Damian Conway's exhaustive and clear book \fIObject Oriented Perl\fR
(Manning Publications 1999, \s-1ISBN 1\-884777\-79\-1\s0).
.SH "BACK"
.IX Header "BACK"
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