Provided by: perl-doc_5.36.0-9ubuntu1.1_all bug

NAME

       perlmodlib - constructing new Perl modules and finding existing ones

THE PERL MODULE LIBRARY

       Many modules are included in the Perl distribution.  These are described below, and all
       end in .pm.  You may discover compiled library files (usually ending in .so) or small
       pieces of modules to be autoloaded (ending in .al); these were automatically generated by
       the installation process.  You may also discover files in the library directory that end
       in either .pl or .ph.  These are old libraries supplied so that old programs that use them
       still run.  The .pl files will all eventually be converted into standard modules, and the
       .ph files made by h2ph will probably end up as extension modules made by h2xs.  (Some .ph
       values may already be available through the POSIX, Errno, or Fcntl modules.)  The pl2pm
       file in the distribution may help in your conversion, but it's just a mechanical process
       and therefore far from bulletproof.

   Pragmatic Modules
       They work somewhat like compiler directives (pragmata) in that they tend to affect the
       compilation of your program, and thus will usually work well only when used within a
       "use", or "no".  Most of these are lexically scoped, so an inner BLOCK may countermand
       them by saying:

           no integer;
           no strict 'refs';
           no warnings;

       which lasts until the end of that BLOCK.

       Some pragmas are lexically scoped--typically those that affect the $^H hints variable.
       Others affect the current package instead, like "use vars" and "use subs", which allow you
       to predeclare a variables or subroutines within a particular file rather than just a
       block.  Such declarations are effective for the entire file for which they were declared.
       You cannot rescind them with "no vars" or "no subs".

       The following pragmas are defined (and have their own documentation).

       attributes  Get/set subroutine or variable attributes

       autodie     Replace functions with ones that succeed or die with lexical scope

       autodie::exception
                   Exceptions from autodying functions.

       autodie::exception::system
                   Exceptions from autodying system().

       autodie::hints
                   Provide hints about user subroutines to autodie

       autodie::skip
                   Skip a package when throwing autodie exceptions

       autouse     Postpone load of modules until a function is used

       base        Establish an ISA relationship with base classes at compile time

       bigfloat    Transparent big floating point number support for Perl

       bigint      Transparent big integer support for Perl

       bignum      Transparent big number support for Perl

       bigrat      Transparent big rational number support for Perl

       blib        Use MakeMaker's uninstalled version of a package

       builtin     Import built-in utility functions

       bytes       Expose the individual bytes of characters

       charnames   Access to Unicode character names and named character sequences; also define
                   character names

       constant    Declare constants

       deprecate   Perl pragma for deprecating the inclusion of a module in core

       diagnostics Produce verbose warning diagnostics

       encoding    Allows you to write your script in non-ASCII and non-UTF-8

       encoding::warnings
                   Warn on implicit encoding conversions

       experimental
                   Experimental features made easy

       feature     Enable new features

       fields      Compile-time class fields

       filetest    Control the filetest permission operators

       if          "use" a Perl module if a condition holds

       integer     Use integer arithmetic instead of floating point

       less        Request less of something

       lib         Manipulate @INC at compile time

       locale      Use or avoid POSIX locales for built-in operations

       mro         Method Resolution Order

       ok          Alternative to Test::More::use_ok

       open        Set default PerlIO layers for input and output

       ops         Restrict unsafe operations when compiling

       overload    Package for overloading Perl operations

       overloading Lexically control overloading

       parent      Establish an ISA relationship with base classes at compile time

       re          Alter regular expression behaviour

       sigtrap     Enable simple signal handling

       sort        Control sort() behaviour

       strict      Restrict unsafe constructs

       subs        Predeclare subroutine names

       threads     Perl interpreter-based threads

       threads::shared
                   Perl extension for sharing data structures between threads

       utf8        Enable/disable UTF-8 (or UTF-EBCDIC) in source code

       vars        Predeclare global variable names

       version     Perl extension for Version Objects

       vmsish      Control VMS-specific language features

       warnings    Control optional warnings

       warnings::register
                   Warnings import function

   Standard Modules
       Standard, bundled modules are all expected to behave in a well-defined manner with respect
       to namespace pollution because they use the Exporter module.  See their own documentation
       for details.

       It's possible that not all modules listed below are installed on your system. For example,
       the GDBM_File module will not be installed if you don't have the gdbm library.

       Amiga::ARexx
                   Perl extension for ARexx support

       Amiga::Exec Perl extension for low level amiga support

       AnyDBM_File Provide framework for multiple DBMs

       App::Cpan   Easily interact with CPAN from the command line

       App::Prove  Implements the "prove" command.

       App::Prove::State
                   State storage for the "prove" command.

       App::Prove::State::Result
                   Individual test suite results.

       App::Prove::State::Result::Test
                   Individual test results.

       Archive::Tar
                   Module for manipulations of tar archives

       Archive::Tar::File
                   A subclass for in-memory extracted file from Archive::Tar

       Attribute::Handlers
                   Simpler definition of attribute handlers

       AutoLoader  Load subroutines only on demand

       AutoSplit   Split a package for autoloading

       B           The Perl Compiler Backend

       B::Concise  Walk Perl syntax tree, printing concise info about ops

       B::Deparse  Perl compiler backend to produce perl code

       B::Op_private
                   OP op_private flag definitions

       B::Showlex  Show lexical variables used in functions or files

       B::Terse    Walk Perl syntax tree, printing terse info about ops

       B::Xref     Generates cross reference reports for Perl programs

       Benchmark   Benchmark running times of Perl code

       "IO::Socket::IP"
                   Family-neutral IP socket supporting both IPv4 and IPv6

       "Socket"    Networking constants and support functions

       CORE        Namespace for Perl's core routines

       CPAN        Query, download and build perl modules from CPAN sites

       CPAN::API::HOWTO
                   A recipe book for programming with CPAN.pm

       CPAN::Debug Internal debugging for CPAN.pm

       CPAN::Distroprefs
                   Read and match distroprefs

       CPAN::FirstTime
                   Utility for CPAN::Config file Initialization

       CPAN::HandleConfig
                   Internal configuration handling for CPAN.pm

       CPAN::Kwalify
                   Interface between CPAN.pm and Kwalify.pm

       CPAN::Meta  The distribution metadata for a CPAN dist

       CPAN::Meta::Converter
                   Convert CPAN distribution metadata structures

       CPAN::Meta::Feature
                   An optional feature provided by a CPAN distribution

       CPAN::Meta::History
                   History of CPAN Meta Spec changes

       CPAN::Meta::History::Meta_1_0
                   Version 1.0 metadata specification for META.yml

       CPAN::Meta::History::Meta_1_1
                   Version 1.1 metadata specification for META.yml

       CPAN::Meta::History::Meta_1_2
                   Version 1.2 metadata specification for META.yml

       CPAN::Meta::History::Meta_1_3
                   Version 1.3 metadata specification for META.yml

       CPAN::Meta::History::Meta_1_4
                   Version 1.4 metadata specification for META.yml

       CPAN::Meta::Merge
                   Merging CPAN Meta fragments

       CPAN::Meta::Prereqs
                   A set of distribution prerequisites by phase and type

       CPAN::Meta::Requirements
                   A set of version requirements for a CPAN dist

       CPAN::Meta::Spec
                   Specification for CPAN distribution metadata

       CPAN::Meta::Validator
                   Validate CPAN distribution metadata structures

       CPAN::Meta::YAML
                   Read and write a subset of YAML for CPAN Meta files

       CPAN::Nox   Wrapper around CPAN.pm without using any XS module

       CPAN::Plugin
                   Base class for CPAN shell extensions

       CPAN::Plugin::Specfile
                   Proof of concept implementation of a trivial CPAN::Plugin

       CPAN::Queue Internal queue support for CPAN.pm

       CPAN::Tarzip
                   Internal handling of tar archives for CPAN.pm

       CPAN::Version
                   Utility functions to compare CPAN versions

       Carp        Alternative warn and die for modules

       Class::Struct
                   Declare struct-like datatypes as Perl classes

       Compress::Raw::Bzip2
                   Low-Level Interface to bzip2 compression library

       Compress::Raw::Zlib
                   Low-Level Interface to zlib compression library

       Compress::Zlib
                   Interface to zlib compression library

       Config      Access Perl configuration information

       Config::Extensions
                   Hash lookup of which core extensions were built.

       Config::Perl::V
                   Structured data retrieval of perl -V output

       Cwd         Get pathname of current working directory

       DB          Programmatic interface to the Perl debugging API

       DBM_Filter  Filter DBM keys/values

       DBM_Filter::compress
                   Filter for DBM_Filter

       DBM_Filter::encode
                   Filter for DBM_Filter

       DBM_Filter::int32
                   Filter for DBM_Filter

       DBM_Filter::null
                   Filter for DBM_Filter

       DBM_Filter::utf8
                   Filter for DBM_Filter

       DB_File     Perl5 access to Berkeley DB version 1.x

       Data::Dumper
                   Stringified perl data structures, suitable for both printing and "eval"

       Devel::PPPort
                   Perl/Pollution/Portability

       Devel::Peek A data debugging tool for the XS programmer

       Devel::SelfStubber
                   Generate stubs for a SelfLoading module

       Digest      Modules that calculate message digests

       Digest::MD5 Perl interface to the MD5 Algorithm

       Digest::SHA Perl extension for SHA-1/224/256/384/512

       Digest::base
                   Digest base class

       Digest::file
                   Calculate digests of files

       DirHandle   (obsolete) supply object methods for directory handles

       Dumpvalue   Provides screen dump of Perl data.

       DynaLoader  Dynamically load C libraries into Perl code

       Encode      Character encodings in Perl

       Encode::Alias
                   Alias definitions to encodings

       Encode::Byte
                   Single Byte Encodings

       Encode::CJKConstants
                   Internally used by Encode::??::ISO_2022_*

       Encode::CN  China-based Chinese Encodings

       Encode::CN::HZ
                   Internally used by Encode::CN

       Encode::Config
                   Internally used by Encode

       Encode::EBCDIC
                   EBCDIC Encodings

       Encode::Encoder
                   Object Oriented Encoder

       Encode::Encoding
                   Encode Implementation Base Class

       Encode::GSM0338
                   ETSI GSM 03.38 Encoding

       Encode::Guess
                   Guesses encoding from data

       Encode::JP  Japanese Encodings

       Encode::JP::H2Z
                   Internally used by Encode::JP::2022_JP*

       Encode::JP::JIS7
                   Internally used by Encode::JP

       Encode::KR  Korean Encodings

       Encode::KR::2022_KR
                   Internally used by Encode::KR

       Encode::MIME::Header
                   MIME encoding for an unstructured email header

       Encode::MIME::Name
                   Internally used by Encode

       Encode::PerlIO
                   A detailed document on Encode and PerlIO

       Encode::Supported
                   Encodings supported by Encode

       Encode::Symbol
                   Symbol Encodings

       Encode::TW  Taiwan-based Chinese Encodings

       Encode::Unicode
                   Various Unicode Transformation Formats

       Encode::Unicode::UTF7
                   UTF-7 encoding

       English     Use nice English (or awk) names for ugly punctuation variables

       Env         Perl module that imports environment variables as scalars or arrays

       Errno       System errno constants

       Exporter    Implements default import method for modules

       Exporter::Heavy
                   Exporter guts

       ExtUtils::CBuilder
                   Compile and link C code for Perl modules

       ExtUtils::CBuilder::Platform::Windows
                   Builder class for Windows platforms

       ExtUtils::Command
                   Utilities to replace common UNIX commands in Makefiles etc.

       ExtUtils::Command::MM
                   Commands for the MM's to use in Makefiles

       ExtUtils::Constant
                   Generate XS code to import C header constants

       ExtUtils::Constant::Base
                   Base class for ExtUtils::Constant objects

       ExtUtils::Constant::Utils
                   Helper functions for ExtUtils::Constant

       ExtUtils::Constant::XS
                   Generate C code for XS modules' constants.

       ExtUtils::Embed
                   Utilities for embedding Perl in C/C++ applications

       ExtUtils::Install
                   Install files from here to there

       ExtUtils::Installed
                   Inventory management of installed modules

       ExtUtils::Liblist
                   Determine libraries to use and how to use them

       ExtUtils::MM
                   OS adjusted ExtUtils::MakeMaker subclass

       ExtUtils::MM_AIX
                   AIX specific subclass of ExtUtils::MM_Unix

       ExtUtils::MM_Any
                   Platform-agnostic MM methods

       ExtUtils::MM_BeOS
                   Methods to override UN*X behaviour in ExtUtils::MakeMaker

       ExtUtils::MM_Cygwin
                   Methods to override UN*X behaviour in ExtUtils::MakeMaker

       ExtUtils::MM_DOS
                   DOS specific subclass of ExtUtils::MM_Unix

       ExtUtils::MM_Darwin
                   Special behaviors for OS X

       ExtUtils::MM_MacOS
                   Once produced Makefiles for MacOS Classic

       ExtUtils::MM_NW5
                   Methods to override UN*X behaviour in ExtUtils::MakeMaker

       ExtUtils::MM_OS2
                   Methods to override UN*X behaviour in ExtUtils::MakeMaker

       ExtUtils::MM_OS390
                   OS390 specific subclass of ExtUtils::MM_Unix

       ExtUtils::MM_QNX
                   QNX specific subclass of ExtUtils::MM_Unix

       ExtUtils::MM_UWIN
                   U/WIN specific subclass of ExtUtils::MM_Unix

       ExtUtils::MM_Unix
                   Methods used by ExtUtils::MakeMaker

       ExtUtils::MM_VMS
                   Methods to override UN*X behaviour in ExtUtils::MakeMaker

       ExtUtils::MM_VOS
                   VOS specific subclass of ExtUtils::MM_Unix

       ExtUtils::MM_Win32
                   Methods to override UN*X behaviour in ExtUtils::MakeMaker

       ExtUtils::MM_Win95
                   Method to customize MakeMaker for Win9X

       ExtUtils::MY
                   ExtUtils::MakeMaker subclass for customization

       ExtUtils::MakeMaker
                   Create a module Makefile

       ExtUtils::MakeMaker::Config
                   Wrapper around Config.pm

       ExtUtils::MakeMaker::FAQ
                   Frequently Asked Questions About MakeMaker

       ExtUtils::MakeMaker::Locale
                   Bundled Encode::Locale

       ExtUtils::MakeMaker::Tutorial
                   Writing a module with MakeMaker

       ExtUtils::Manifest
                   Utilities to write and check a MANIFEST file

       ExtUtils::Miniperl
                   Write the C code for miniperlmain.c and perlmain.c

       ExtUtils::Mkbootstrap
                   Make a bootstrap file for use by DynaLoader

       ExtUtils::Mksymlists
                   Write linker options files for dynamic extension

       ExtUtils::PL2Bat
                   Batch file creation to run perl scripts on Windows

       ExtUtils::Packlist
                   Manage .packlist files

       ExtUtils::ParseXS
                   Converts Perl XS code into C code

       ExtUtils::ParseXS::Constants
                   Initialization values for some globals

       ExtUtils::ParseXS::Eval
                   Clean package to evaluate code in

       ExtUtils::ParseXS::Utilities
                   Subroutines used with ExtUtils::ParseXS

       ExtUtils::Typemaps
                   Read/Write/Modify Perl/XS typemap files

       ExtUtils::Typemaps::Cmd
                   Quick commands for handling typemaps

       ExtUtils::Typemaps::InputMap
                   Entry in the INPUT section of a typemap

       ExtUtils::Typemaps::OutputMap
                   Entry in the OUTPUT section of a typemap

       ExtUtils::Typemaps::Type
                   Entry in the TYPEMAP section of a typemap

       ExtUtils::XSSymSet
                   Keep sets of symbol names palatable to the VMS linker

       ExtUtils::testlib
                   Add blib/* directories to @INC

       Fatal       Replace functions with equivalents which succeed or die

       Fcntl       Load the C Fcntl.h defines

       File::Basename
                   Parse file paths into directory, filename and suffix.

       File::Compare
                   Compare files or filehandles

       File::Copy  Copy files or filehandles

       File::DosGlob
                   DOS like globbing and then some

       File::Fetch A generic file fetching mechanism

       File::Find  Traverse a directory tree.

       File::Glob  Perl extension for BSD glob routine

       File::GlobMapper
                   Extend File Glob to Allow Input and Output Files

       File::Path  Create or remove directory trees

       File::Spec  Portably perform operations on file names

       File::Spec::AmigaOS
                   File::Spec for AmigaOS

       File::Spec::Cygwin
                   Methods for Cygwin file specs

       File::Spec::Epoc
                   Methods for Epoc file specs

       File::Spec::Functions
                   Portably perform operations on file names

       File::Spec::Mac
                   File::Spec for Mac OS (Classic)

       File::Spec::OS2
                   Methods for OS/2 file specs

       File::Spec::Unix
                   File::Spec for Unix, base for other File::Spec modules

       File::Spec::VMS
                   Methods for VMS file specs

       File::Spec::Win32
                   Methods for Win32 file specs

       File::Temp  Return name and handle of a temporary file safely

       File::stat  By-name interface to Perl's built-in stat() functions

       FileCache   Keep more files open than the system permits

       FileHandle  Supply object methods for filehandles

       Filter::Simple
                   Simplified source filtering

       Filter::Util::Call
                   Perl Source Filter Utility Module

       FindBin     Locate directory of original perl script

       GDBM_File   Perl5 access to the gdbm library.

       Getopt::Long
                   Extended processing of command line options

       Getopt::Std Process single-character switches with switch clustering

       HTTP::Tiny  A small, simple, correct HTTP/1.1 client

       Hash::Util  A selection of general-utility hash subroutines

       Hash::Util::FieldHash
                   Support for Inside-Out Classes

       I18N::Collate
                   Compare 8-bit scalar data according to the current locale

       I18N::LangTags
                   Functions for dealing with RFC3066-style language tags

       I18N::LangTags::Detect
                   Detect the user's language preferences

       I18N::LangTags::List
                   Tags and names for human languages

       I18N::Langinfo
                   Query locale information

       IO          Load various IO modules

       IO::Compress::Base
                   Base Class for IO::Compress modules

       IO::Compress::Bzip2
                   Write bzip2 files/buffers

       IO::Compress::Deflate
                   Write RFC 1950 files/buffers

       IO::Compress::FAQ
                   Frequently Asked Questions about IO::Compress

       IO::Compress::Gzip
                   Write RFC 1952 files/buffers

       IO::Compress::RawDeflate
                   Write RFC 1951 files/buffers

       IO::Compress::Zip
                   Write zip files/buffers

       IO::Dir     Supply object methods for directory handles

       IO::File    Supply object methods for filehandles

       IO::Handle  Supply object methods for I/O handles

       IO::Pipe    Supply object methods for pipes

       IO::Poll    Object interface to system poll call

       IO::Seekable
                   Supply seek based methods for I/O objects

       IO::Select  OO interface to the select system call

       IO::Socket  Object interface to socket communications

       IO::Socket::INET
                   Object interface for AF_INET domain sockets

       IO::Socket::UNIX
                   Object interface for AF_UNIX domain sockets

       IO::Uncompress::AnyInflate
                   Uncompress zlib-based (zip, gzip) file/buffer

       IO::Uncompress::AnyUncompress
                   Uncompress gzip, zip, bzip2, zstd, xz, lzma, lzip, lzf or lzop file/buffer

       IO::Uncompress::Base
                   Base Class for IO::Uncompress modules

       IO::Uncompress::Bunzip2
                   Read bzip2 files/buffers

       IO::Uncompress::Gunzip
                   Read RFC 1952 files/buffers

       IO::Uncompress::Inflate
                   Read RFC 1950 files/buffers

       IO::Uncompress::RawInflate
                   Read RFC 1951 files/buffers

       IO::Uncompress::Unzip
                   Read zip files/buffers

       IO::Zlib    IO:: style interface to Compress::Zlib

       IPC::Cmd    Finding and running system commands made easy

       IPC::Msg    SysV Msg IPC object class

       IPC::Open2  Open a process for both reading and writing using open2()

       IPC::Open3  Open a process for reading, writing, and error handling using open3()

       IPC::Semaphore
                   SysV Semaphore IPC object class

       IPC::SharedMem
                   SysV Shared Memory IPC object class

       IPC::SysV   System V IPC constants and system calls

       Internals   Reserved special namespace for internals related functions

       JSON::PP    JSON::XS compatible pure-Perl module.

       JSON::PP::Boolean
                   Dummy module providing JSON::PP::Boolean

       List::Util  A selection of general-utility list subroutines

       List::Util::XS
                   Indicate if List::Util was compiled with a C compiler

       Locale::Maketext
                   Framework for localization

       Locale::Maketext::Cookbook
                   Recipes for using Locale::Maketext

       Locale::Maketext::Guts
                   Deprecated module to load Locale::Maketext utf8 code

       Locale::Maketext::GutsLoader
                   Deprecated module to load Locale::Maketext utf8 code

       Locale::Maketext::Simple
                   Simple interface to Locale::Maketext::Lexicon

       Locale::Maketext::TPJ13
                   Article about software localization

       MIME::Base64
                   Encoding and decoding of base64 strings

       MIME::QuotedPrint
                   Encoding and decoding of quoted-printable strings

       Math::BigFloat
                   Arbitrary size floating point math package

       Math::BigInt
                   Arbitrary size integer math package

       Math::BigInt::Calc
                   Pure Perl module to support Math::BigInt

       Math::BigInt::FastCalc
                   Math::BigInt::Calc with some XS for more speed

       Math::BigInt::Lib
                   Virtual parent class for Math::BigInt libraries

       Math::BigRat
                   Arbitrary size rational number math package

       Math::Complex
                   Complex numbers and associated mathematical functions

       Math::Trig  Trigonometric functions

       Memoize     Make functions faster by trading space for time

       Memoize::AnyDBM_File
                   Glue to provide EXISTS for AnyDBM_File for Storable use

       Memoize::Expire
                   Plug-in module for automatic expiration of memoized values

       Memoize::ExpireFile
                   Test for Memoize expiration semantics

       Memoize::ExpireTest
                   Test for Memoize expiration semantics

       Memoize::NDBM_File
                   Glue to provide EXISTS for NDBM_File for Storable use

       Memoize::SDBM_File
                   Glue to provide EXISTS for SDBM_File for Storable use

       Memoize::Storable
                   Store Memoized data in Storable database

       Module::CoreList
                   What modules shipped with versions of perl

       Module::CoreList::Utils
                   What utilities shipped with versions of perl

       Module::Load
                   Runtime require of both modules and files

       Module::Load::Conditional
                   Looking up module information / loading at runtime

       Module::Loaded
                   Mark modules as loaded or unloaded

       Module::Metadata
                   Gather package and POD information from perl module files

       NDBM_File   Tied access to ndbm files

       NEXT        Provide a pseudo-class NEXT (et al) that allows method redispatch

       Net::Cmd    Network Command class (as used by FTP, SMTP etc)

       Net::Config Local configuration data for libnet

       Net::Domain Attempt to evaluate the current host's internet name and domain

       Net::FTP    FTP Client class

       Net::FTP::dataconn
                   FTP Client data connection class

       Net::NNTP   NNTP Client class

       Net::Netrc  OO interface to users netrc file

       Net::POP3   Post Office Protocol 3 Client class (RFC1939)

       Net::Ping   Check a remote host for reachability

       Net::SMTP   Simple Mail Transfer Protocol Client

       Net::Time   Time and daytime network client interface

       Net::hostent
                   By-name interface to Perl's built-in gethost*() functions

       Net::libnetFAQ
                   Libnet Frequently Asked Questions

       Net::netent By-name interface to Perl's built-in getnet*() functions

       Net::protoent
                   By-name interface to Perl's built-in getproto*() functions

       Net::servent
                   By-name interface to Perl's built-in getserv*() functions

       O           Generic interface to Perl Compiler backends

       ODBM_File   Tied access to odbm files

       Opcode      Disable named opcodes when compiling perl code

       POSIX       Perl interface to IEEE Std 1003.1

       Params::Check
                   A generic input parsing/checking mechanism.

       Parse::CPAN::Meta
                   Parse META.yml and META.json CPAN metadata files

       Perl::OSType
                   Map Perl operating system names to generic types

       PerlIO      On demand loader for PerlIO layers and root of PerlIO::* name space

       PerlIO::encoding
                   Encoding layer

       PerlIO::mmap
                   Memory mapped IO

       PerlIO::scalar
                   In-memory IO, scalar IO

       PerlIO::via Helper class for PerlIO layers implemented in perl

       PerlIO::via::QuotedPrint
                   PerlIO layer for quoted-printable strings

       Pod::Checker
                   Check pod documents for syntax errors

       Pod::Escapes
                   For resolving Pod E<...> sequences

       Pod::Functions
                   Group Perl's functions a la perlfunc.pod

       Pod::Html   Module to convert pod files to HTML

       Pod::Html::Util
                   Helper functions for Pod-Html

       Pod::Man    Convert POD data to formatted *roff input

       Pod::ParseLink
                   Parse an L<> formatting code in POD text

       Pod::Perldoc
                   Look up Perl documentation in Pod format.

       Pod::Perldoc::BaseTo
                   Base for Pod::Perldoc formatters

       Pod::Perldoc::GetOptsOO
                   Customized option parser for Pod::Perldoc

       Pod::Perldoc::ToANSI
                   Render Pod with ANSI color escapes

       Pod::Perldoc::ToChecker
                   Let Perldoc check Pod for errors

       Pod::Perldoc::ToMan
                   Let Perldoc render Pod as man pages

       Pod::Perldoc::ToNroff
                   Let Perldoc convert Pod to nroff

       Pod::Perldoc::ToPod
                   Let Perldoc render Pod as ... Pod!

       Pod::Perldoc::ToRtf
                   Let Perldoc render Pod as RTF

       Pod::Perldoc::ToTerm
                   Render Pod with terminal escapes

       Pod::Perldoc::ToText
                   Let Perldoc render Pod as plaintext

       Pod::Perldoc::ToTk
                   Let Perldoc use Tk::Pod to render Pod

       Pod::Perldoc::ToXml
                   Let Perldoc render Pod as XML

       Pod::Simple Framework for parsing Pod

       Pod::Simple::Checker
                   Check the Pod syntax of a document

       Pod::Simple::Debug
                   Put Pod::Simple into trace/debug mode

       Pod::Simple::DumpAsText
                   Dump Pod-parsing events as text

       Pod::Simple::DumpAsXML
                   Turn Pod into XML

       Pod::Simple::HTML
                   Convert Pod to HTML

       Pod::Simple::HTMLBatch
                   Convert several Pod files to several HTML files

       Pod::Simple::JustPod
                   Just the Pod, the whole Pod, and nothing but the Pod

       Pod::Simple::LinkSection
                   Represent "section" attributes of L codes

       Pod::Simple::Methody
                   Turn Pod::Simple events into method calls

       Pod::Simple::PullParser
                   A pull-parser interface to parsing Pod

       Pod::Simple::PullParserEndToken
                   End-tokens from Pod::Simple::PullParser

       Pod::Simple::PullParserStartToken
                   Start-tokens from Pod::Simple::PullParser

       Pod::Simple::PullParserTextToken
                   Text-tokens from Pod::Simple::PullParser

       Pod::Simple::PullParserToken
                   Tokens from Pod::Simple::PullParser

       Pod::Simple::RTF
                   Format Pod as RTF

       Pod::Simple::Search
                   Find POD documents in directory trees

       Pod::Simple::SimpleTree
                   Parse Pod into a simple parse tree

       Pod::Simple::Subclassing
                   Write a formatter as a Pod::Simple subclass

       Pod::Simple::Text
                   Format Pod as plaintext

       Pod::Simple::TextContent
                   Get the text content of Pod

       Pod::Simple::XHTML
                   Format Pod as validating XHTML

       Pod::Simple::XMLOutStream
                   Turn Pod into XML

       Pod::Text   Convert POD data to formatted text

       Pod::Text::Color
                   Convert POD data to formatted color ASCII text

       Pod::Text::Overstrike
                   Convert POD data to formatted overstrike text

       Pod::Text::Termcap
                   Convert POD data to ASCII text with format escapes

       Pod::Usage  Extracts POD documentation and shows usage information

       SDBM_File   Tied access to sdbm files

       Safe        Compile and execute code in restricted compartments

       Scalar::Util
                   A selection of general-utility scalar subroutines

       Search::Dict
                   Look - search for key in dictionary file

       SelectSaver Save and restore selected file handle

       SelfLoader  Load functions only on demand

       Storable    Persistence for Perl data structures

       Sub::Util   A selection of utility subroutines for subs and CODE references

       Symbol      Manipulate Perl symbols and their names

       Sys::Hostname
                   Try every conceivable way to get hostname

       Sys::Syslog Perl interface to the UNIX syslog(3) calls

       Sys::Syslog::Win32
                   Win32 support for Sys::Syslog

       TAP::Base   Base class that provides common functionality to TAP::Parser

       TAP::Formatter::Base
                   Base class for harness output delegates

       TAP::Formatter::Color
                   Run Perl test scripts with color

       TAP::Formatter::Console
                   Harness output delegate for default console output

       TAP::Formatter::Console::ParallelSession
                   Harness output delegate for parallel console output

       TAP::Formatter::Console::Session
                   Harness output delegate for default console output

       TAP::Formatter::File
                   Harness output delegate for file output

       TAP::Formatter::File::Session
                   Harness output delegate for file output

       TAP::Formatter::Session
                   Abstract base class for harness output delegate

       TAP::Harness
                   Run test scripts with statistics

       TAP::Harness::Env
                   Parsing harness related environmental variables where appropriate

       TAP::Object Base class that provides common functionality to all "TAP::*" modules

       TAP::Parser Parse TAP output

       TAP::Parser::Aggregator
                   Aggregate TAP::Parser results

       TAP::Parser::Grammar
                   A grammar for the Test Anything Protocol.

       TAP::Parser::Iterator
                   Base class for TAP source iterators

       TAP::Parser::Iterator::Array
                   Iterator for array-based TAP sources

       TAP::Parser::Iterator::Process
                   Iterator for process-based TAP sources

       TAP::Parser::Iterator::Stream
                   Iterator for filehandle-based TAP sources

       TAP::Parser::IteratorFactory
                   Figures out which SourceHandler objects to use for a given Source

       TAP::Parser::Multiplexer
                   Multiplex multiple TAP::Parsers

       TAP::Parser::Result
                   Base class for TAP::Parser output objects

       TAP::Parser::Result::Bailout
                   Bailout result token.

       TAP::Parser::Result::Comment
                   Comment result token.

       TAP::Parser::Result::Plan
                   Plan result token.

       TAP::Parser::Result::Pragma
                   TAP pragma token.

       TAP::Parser::Result::Test
                   Test result token.

       TAP::Parser::Result::Unknown
                   Unknown result token.

       TAP::Parser::Result::Version
                   TAP syntax version token.

       TAP::Parser::Result::YAML
                   YAML result token.

       TAP::Parser::ResultFactory
                   Factory for creating TAP::Parser output objects

       TAP::Parser::Scheduler
                   Schedule tests during parallel testing

       TAP::Parser::Scheduler::Job
                   A single testing job.

       TAP::Parser::Scheduler::Spinner
                   A no-op job.

       TAP::Parser::Source
                   A TAP source & meta data about it

       TAP::Parser::SourceHandler
                   Base class for different TAP source handlers

       TAP::Parser::SourceHandler::Executable
                   Stream output from an executable TAP source

       TAP::Parser::SourceHandler::File
                   Stream TAP from a text file.

       TAP::Parser::SourceHandler::Handle
                   Stream TAP from an IO::Handle or a GLOB.

       TAP::Parser::SourceHandler::Perl
                   Stream TAP from a Perl executable

       TAP::Parser::SourceHandler::RawTAP
                   Stream output from raw TAP in a scalar/array ref.

       TAP::Parser::YAMLish::Reader
                   Read YAMLish data from iterator

       TAP::Parser::YAMLish::Writer
                   Write YAMLish data

       Term::ANSIColor
                   Color screen output using ANSI escape sequences

       Term::Cap   Perl termcap interface

       Term::Complete
                   Perl word completion module

       Term::ReadLine
                   Perl interface to various "readline" packages.

       Test        Provides a simple framework for writing test scripts

       Test2       Framework for writing test tools that all work together.

       Test2::API  Primary interface for writing Test2 based testing tools.

       Test2::API::Breakage
                   What breaks at what version

       Test2::API::Context
                   Object to represent a testing context.

       Test2::API::Instance
                   Object used by Test2::API under the hood

       Test2::API::InterceptResult
                   Representation of a list of events.

       Test2::API::InterceptResult::Event
                   Representation of an event for use in

       Test2::API::InterceptResult::Hub
                   Hub used by InterceptResult.

       Test2::API::InterceptResult::Squasher
                   Encapsulation of the algorithm that

       Test2::API::Stack
                   Object to manage a stack of Test2::Hub

       Test2::Event
                   Base class for events

       Test2::Event::Bail
                   Bailout!

       Test2::Event::Diag
                   Diag event type

       Test2::Event::Encoding
                   Set the encoding for the output stream

       Test2::Event::Exception
                   Exception event

       Test2::Event::Fail
                   Event for a simple failed assertion

       Test2::Event::Generic
                   Generic event type.

       Test2::Event::Note
                   Note event type

       Test2::Event::Ok
                   Ok event type

       Test2::Event::Pass
                   Event for a simple passing assertion

       Test2::Event::Plan
                   The event of a plan

       Test2::Event::Skip
                   Skip event type

       Test2::Event::Subtest
                   Event for subtest types

       Test2::Event::TAP::Version
                   Event for TAP version.

       Test2::Event::V2
                   Second generation event.

       Test2::Event::Waiting
                   Tell all procs/threads it is time to be done

       Test2::EventFacet
                   Base class for all event facets.

       Test2::EventFacet::About
                   Facet with event details.

       Test2::EventFacet::Amnesty
                   Facet for assertion amnesty.

       Test2::EventFacet::Assert
                   Facet representing an assertion.

       Test2::EventFacet::Control
                   Facet for hub actions and behaviors.

       Test2::EventFacet::Error
                   Facet for errors that need to be shown.

       Test2::EventFacet::Hub
                   Facet for the hubs an event passes through.

       Test2::EventFacet::Info
                   Facet for information a developer might care about.

       Test2::EventFacet::Info::Table
                   Intermediary representation of a table.

       Test2::EventFacet::Meta
                   Facet for meta-data

       Test2::EventFacet::Parent
                   Facet for events contains other events

       Test2::EventFacet::Plan
                   Facet for setting the plan

       Test2::EventFacet::Render
                   Facet that dictates how to render an event.

       Test2::EventFacet::Trace
                   Debug information for events

       Test2::Formatter
                   Namespace for formatters.

       Test2::Formatter::TAP
                   Standard TAP formatter

       Test2::Hub  The conduit through which all events flow.

       Test2::Hub::Interceptor
                   Hub used by interceptor to grab results.

       Test2::Hub::Interceptor::Terminator
                   Exception class used by

       Test2::Hub::Subtest
                   Hub used by subtests

       Test2::IPC  Turn on IPC for threading or forking support.

       Test2::IPC::Driver
                   Base class for Test2 IPC drivers.

       Test2::IPC::Driver::Files
                   Temp dir + Files concurrency model.

       Test2::Tools::Tiny
                   Tiny set of tools for unfortunate souls who cannot use

       Test2::Transition
                   Transition notes when upgrading to Test2

       Test2::Util Tools used by Test2 and friends.

       Test2::Util::ExternalMeta
                   Allow third party tools to safely attach meta-data

       Test2::Util::Facets2Legacy
                   Convert facet data to the legacy event API.

       Test2::Util::HashBase
                   Build hash based classes.

       Test2::Util::Trace
                   Legacy wrapper fro Test2::EventFacet::Trace.

       Test::Builder
                   Backend for building test libraries

       Test::Builder::Formatter
                   Test::Builder subclass of Test2::Formatter::TAP

       Test::Builder::IO::Scalar
                   A copy of IO::Scalar for Test::Builder

       Test::Builder::Module
                   Base class for test modules

       Test::Builder::Tester
                   Test testsuites that have been built with

       Test::Builder::Tester::Color
                   Turn on colour in Test::Builder::Tester

       Test::Builder::TodoDiag
                   Test::Builder subclass of Test2::Event::Diag

       Test::Harness
                   Run Perl standard test scripts with statistics

       Test::Harness::Beyond
                   Beyond make test

       Test::More  Yet another framework for writing test scripts

       Test::Simple
                   Basic utilities for writing tests.

       Test::Tester
                   Ease testing test modules built with Test::Builder

       Test::Tester::Capture
                   Help testing test modules built with Test::Builder

       Test::Tester::CaptureRunner
                   Help testing test modules built with Test::Builder

       Test::Tutorial
                   A tutorial about writing really basic tests

       Test::use::ok
                   Alternative to Test::More::use_ok

       Text::Abbrev
                   Abbrev - create an abbreviation table from a list

       Text::Balanced
                   Extract delimited text sequences from strings.

       Text::ParseWords
                   Parse text into an array of tokens or array of arrays

       Text::Tabs  Expand and unexpand tabs like unix expand(1) and unexpand(1)

       Text::Wrap  Line wrapping to form simple paragraphs

       Thread      Manipulate threads in Perl (for old code only)

       Thread::Queue
                   Thread-safe queues

       Thread::Semaphore
                   Thread-safe semaphores

       Tie::Array  Base class for tied arrays

       Tie::File   Access the lines of a disk file via a Perl array

       Tie::Handle Base class definitions for tied handles

       Tie::Hash   Base class definitions for tied hashes

       Tie::Hash::NamedCapture
                   Named regexp capture buffers

       Tie::Memoize
                   Add data to hash when needed

       Tie::RefHash
                   Use references as hash keys

       Tie::Scalar Base class definitions for tied scalars

       Tie::StdHandle
                   Base class definitions for tied handles

       Tie::SubstrHash
                   Fixed-table-size, fixed-key-length hashing

       Time::HiRes High resolution alarm, sleep, gettimeofday, interval timers

       Time::Local Efficiently compute time from local and GMT time

       Time::Piece Object Oriented time objects

       Time::Seconds
                   A simple API to convert seconds to other date values

       Time::gmtime
                   By-name interface to Perl's built-in gmtime() function

       Time::localtime
                   By-name interface to Perl's built-in localtime() function

       Time::tm    Internal object used by Time::gmtime and Time::localtime

       UNIVERSAL   Base class for ALL classes (blessed references)

       Unicode::Collate
                   Unicode Collation Algorithm

       Unicode::Collate::CJK::Big5
                   Weighting CJK Unified Ideographs

       Unicode::Collate::CJK::GB2312
                   Weighting CJK Unified Ideographs

       Unicode::Collate::CJK::JISX0208
                   Weighting JIS KANJI for Unicode::Collate

       Unicode::Collate::CJK::Korean
                   Weighting CJK Unified Ideographs

       Unicode::Collate::CJK::Pinyin
                   Weighting CJK Unified Ideographs

       Unicode::Collate::CJK::Stroke
                   Weighting CJK Unified Ideographs

       Unicode::Collate::CJK::Zhuyin
                   Weighting CJK Unified Ideographs

       Unicode::Collate::Locale
                   Linguistic tailoring for DUCET via Unicode::Collate

       Unicode::Normalize
                   Unicode Normalization Forms

       Unicode::UCD
                   Unicode character database

       User::grent By-name interface to Perl's built-in getgr*() functions

       User::pwent By-name interface to Perl's built-in getpw*() functions

       VMS::DCLsym Perl extension to manipulate DCL symbols

       VMS::Filespec
                   Convert between VMS and Unix file specification syntax

       VMS::Stdio  Standard I/O functions via VMS extensions

       Win32       Interfaces to some Win32 API Functions

       Win32API::File
                   Low-level access to Win32 system API calls for files/dirs.

       Win32CORE   Win32 CORE function stubs

       XS::APItest Test the perl C API

       XS::Typemap Module to test the XS typemaps distributed with perl

       XSLoader    Dynamically load C libraries into Perl code

       autodie::Scope::Guard
                   Wrapper class for calling subs at end of scope

       autodie::Scope::GuardStack
                   Hook stack for managing scopes via %^H

       autodie::Util
                   Internal Utility subroutines for autodie and Fatal

       version::Internals
                   Perl extension for Version Objects

       To find out all modules installed on your system, including those without documentation or
       outside the standard release, just use the following command (under the default win32
       shell, double quotes should be used instead of single quotes).

           % perl -MFile::Find=find -MFile::Spec::Functions -Tlwe \
             'find { wanted => sub { print canonpath $_ if /\.pm\z/ },
             no_chdir => 1 }, @INC'

       (The -T is here to prevent @INC from being populated by "PERL5LIB", "PERLLIB", and
       "PERL_USE_UNSAFE_INC".)  They should all have their own documentation installed and
       accessible via your system man(1) command.  If you do not have a find program, you can use
       the Perl find2perl program instead, which generates Perl code as output you can run
       through perl.  If you have a man program but it doesn't find your modules, you'll have to
       fix your manpath.  See perl for details.  If you have no system man command, you might try
       the perldoc program.

       Note also that the command "perldoc perllocal" gives you a (possibly incomplete) list of
       the modules that have been further installed on your system. (The perllocal.pod file is
       updated by the standard MakeMaker install process.)

   Extension Modules
       Extension modules are written in C (or a mix of Perl and C).  They are usually dynamically
       loaded into Perl if and when you need them, but may also be linked in statically.
       Supported extension modules include Socket, Fcntl, and POSIX.

       Many popular C extension modules do not come bundled (at least, not completely) due to
       their sizes, volatility, or simply lack of time for adequate testing and configuration
       across the multitude of platforms on which Perl was beta-tested.  You are encouraged to
       look for them on CPAN (described below), or using web search engines like Google or
       DuckDuckGo.

CPAN

       CPAN stands for Comprehensive Perl Archive Network; it's a globally replicated trove of
       Perl materials, including documentation, style guides, tricks and traps, alternate ports
       to non-Unix systems and occasional binary distributions for these.   Search engines for
       CPAN can be found at https://www.cpan.org/

       Most importantly, CPAN includes around a thousand unbundled modules, some of which require
       a C compiler to build.  Major categories of modules are:

       •   Language Extensions and Documentation Tools

       •   Development Support

       •   Operating System Interfaces

       •   Networking, Device Control (modems) and InterProcess Communication

       •   Data Types and Data Type Utilities

       •   Database Interfaces

       •   User Interfaces

       •   Interfaces to / Emulations of Other Programming Languages

       •   File Names, File Systems and File Locking (see also File Handles)

       •   String Processing, Language Text Processing, Parsing, and Searching

       •   Option, Argument, Parameter, and Configuration File Processing

       •   Internationalization and Locale

       •   Authentication, Security, and Encryption

       •   World Wide Web, HTML, HTTP, CGI, MIME

       •   Server and Daemon Utilities

       •   Archiving and Compression

       •   Images, Pixmap and Bitmap Manipulation, Drawing, and Graphing

       •   Mail and Usenet News

       •   Control Flow Utilities (callbacks and exceptions etc)

       •   File Handle and Input/Output Stream Utilities

       •   Miscellaneous Modules

       You can find the CPAN online at <https://www.cpan.org/>

Modules: Creation, Use, and Abuse

       (The following section is borrowed directly from Tim Bunce's modules file, available at
       your nearest CPAN site.)

       Perl implements a class using a package, but the presence of a package doesn't imply the
       presence of a class.  A package is just a namespace.  A class is a package that provides
       subroutines that can be used as methods.  A method is just a subroutine that expects, as
       its first argument, either the name of a package (for "static" methods), or a reference to
       something (for "virtual" methods).

       A module is a file that (by convention) provides a class of the same name (sans the .pm),
       plus an import method in that class that can be called to fetch exported symbols.  This
       module may implement some of its methods by loading dynamic C or C++ objects, but that
       should be totally transparent to the user of the module.  Likewise, the module might set
       up an AUTOLOAD function to slurp in subroutine definitions on demand, but this is also
       transparent.  Only the .pm file is required to exist.  See perlsub, perlobj, and
       AutoLoader for details about the AUTOLOAD mechanism.

   Guidelines for Module Creation
       •   Do similar modules already exist in some form?

           If so, please try to reuse the existing modules either in whole or by inheriting
           useful features into a new class.  If this is not practical try to get together with
           the module authors to work on extending or enhancing the functionality of the existing
           modules.  A perfect example is the plethora of packages in perl4 for dealing with
           command line options.

           If you are writing a module to expand an already existing set of modules, please
           coordinate with the author of the package.  It helps if you follow the same naming
           scheme and module interaction scheme as the original author.

       •   Try to design the new module to be easy to extend and reuse.

           Try to "use warnings;" (or "use warnings qw(...);").  Remember that you can add "no
           warnings qw(...);" to individual blocks of code that need less warnings.

           Use blessed references.  Use the two argument form of bless to bless into the class
           name given as the first parameter of the constructor, e.g.,:

            sub new {
                my $class = shift;
                return bless {}, $class;
            }

           or even this if you'd like it to be used as either a static or a virtual method.

            sub new {
                my $self  = shift;
                my $class = ref($self) || $self;
                return bless {}, $class;
            }

           Pass arrays as references so more parameters can be added later (it's also faster).
           Convert functions into methods where appropriate.  Split large methods into smaller
           more flexible ones.  Inherit methods from other modules if appropriate.

           Avoid class name tests like: "die "Invalid" unless ref $ref eq 'FOO'".  Generally you
           can delete the "eq 'FOO'" part with no harm at all.  Let the objects look after
           themselves! Generally, avoid hard-wired class names as far as possible.

           Avoid "$r->Class::func()" where using "@ISA=qw(... Class ...)" and "$r->func()" would
           work.

           Use autosplit so little used or newly added functions won't be a burden to programs
           that don't use them. Add test functions to the module after __END__ either using
           AutoSplit or by saying:

            eval join('',<main::DATA>) || die $@ unless caller();

           Does your module pass the 'empty subclass' test? If you say "@SUBCLASS::ISA =
           qw(YOURCLASS);" your applications should be able to use SUBCLASS in exactly the same
           way as YOURCLASS.  For example, does your application still work if you change:  "$obj
           = YOURCLASS->new();" into: "$obj = SUBCLASS->new();" ?

           Avoid keeping any state information in your packages. It makes it difficult for
           multiple other packages to use yours. Keep state information in objects.

           Always use -w.

           Try to "use strict;" (or "use strict qw(...);").  Remember that you can add "no strict
           qw(...);" to individual blocks of code that need less strictness.

           Always use -w.

           Follow the guidelines in perlstyle.

           Always use -w.

       •   Some simple style guidelines

           The perlstyle manual supplied with Perl has many helpful points.

           Coding style is a matter of personal taste. Many people evolve their style over
           several years as they learn what helps them write and maintain good code.  Here's one
           set of assorted suggestions that seem to be widely used by experienced developers:

           Use underscores to separate words.  It is generally easier to read
           $var_names_like_this than $VarNamesLikeThis, especially for non-native speakers of
           English. It's also a simple rule that works consistently with VAR_NAMES_LIKE_THIS.

           Package/Module names are an exception to this rule. Perl informally reserves lowercase
           module names for 'pragma' modules like integer and strict. Other modules normally
           begin with a capital letter and use mixed case with no underscores (need to be short
           and portable).

           You may find it helpful to use letter case to indicate the scope or nature of a
           variable. For example:

            $ALL_CAPS_HERE   constants only (beware clashes with Perl vars)
            $Some_Caps_Here  package-wide global/static
            $no_caps_here    function scope my() or local() variables

           Function and method names seem to work best as all lowercase.  e.g.,
           "$obj->as_string()".

           You can use a leading underscore to indicate that a variable or function should not be
           used outside the package that defined it.

       •   Select what to export.

           Do NOT export method names!

           Do NOT export anything else by default without a good reason!

           Exports pollute the namespace of the module user.  If you must export try to use
           @EXPORT_OK in preference to @EXPORT and avoid short or common names to reduce the risk
           of name clashes.

           Generally anything not exported is still accessible from outside the module using the
           ModuleName::item_name (or "$blessed_ref->method") syntax.  By convention you can use a
           leading underscore on names to indicate informally that they are 'internal' and not
           for public use.

           (It is actually possible to get private functions by saying: "my $subref = sub { ...
           };  &$subref;".  But there's no way to call that directly as a method, because a
           method must have a name in the symbol table.)

           As a general rule, if the module is trying to be object oriented then export nothing.
           If it's just a collection of functions then @EXPORT_OK anything but use @EXPORT with
           caution.

       •   Select a name for the module.

           This name should be as descriptive, accurate, and complete as possible.  Avoid any
           risk of ambiguity. Always try to use two or more whole words.  Generally the name
           should reflect what is special about what the module does rather than how it does it.
           Please use nested module names to group informally or categorize a module.  There
           should be a very good reason for a module not to have a nested name.  Module names
           should begin with a capital letter.

           Having 57 modules all called Sort will not make life easy for anyone (though having 23
           called Sort::Quick is only marginally better :-).  Imagine someone trying to install
           your module alongside many others.

           If you are developing a suite of related modules/classes it's good practice to use
           nested classes with a common prefix as this will avoid namespace clashes. For example:
           Xyz::Control, Xyz::View, Xyz::Model etc. Use the modules in this list as a naming
           guide.

           If adding a new module to a set, follow the original author's standards for naming
           modules and the interface to methods in those modules.

           If developing modules for private internal or project specific use, that will never be
           released to the public, then you should ensure that their names will not clash with
           any future public module. You can do this either by using the reserved Local::*
           category or by using a category name that includes an underscore like Foo_Corp::*.

           To be portable each component of a module name should be limited to 11 characters. If
           it might be used on MS-DOS then try to ensure each is unique in the first 8
           characters. Nested modules make this easier.

           For additional guidance on the naming of modules, please consult:

               https://pause.perl.org/pause/query?ACTION=pause_namingmodules

           or send mail to the <module-authors@perl.org> mailing list.

       •   Have you got it right?

           How do you know that you've made the right decisions? Have you picked an interface
           design that will cause problems later? Have you picked the most appropriate name? Do
           you have any questions?

           The best way to know for sure, and pick up many helpful suggestions, is to ask someone
           who knows. The <module-authors@perl.org> mailing list is useful for this purpose; it's
           also accessible via news interface as perl.module-authors at nntp.perl.org.

           All you need to do is post a short summary of the module, its purpose and interfaces.
           A few lines on each of the main methods is probably enough. (If you post the whole
           module it might be ignored by busy people - generally the very people you want to read
           it!)

           Don't worry about posting if you can't say when the module will be ready - just say so
           in the message. It might be worth inviting others to help you, they may be able to
           complete it for you!

       •   README and other Additional Files.

           It's well known that software developers usually fully document the software they
           write. If, however, the world is in urgent need of your software and there is not
           enough time to write the full documentation please at least provide a README file
           containing:

           •         A description of the module/package/extension etc.

           •         A copyright notice - see below.

           •         Prerequisites - what else you may need to have.

           •         How to build it - possible changes to Makefile.PL etc.

           •         How to install it.

           •         Recent changes in this release, especially incompatibilities

           •         Changes / enhancements you plan to make in the future.

           If the README file seems to be getting too large you may wish to split out some of the
           sections into separate files: INSTALL, Copying, ToDo etc.

           •   Adding a Copyright Notice.

               How you choose to license your work is a personal decision.  The general mechanism
               is to assert your Copyright and then make a declaration of how others may
               copy/use/modify your work.

               Perl, for example, is supplied with two types of licence: The GNU GPL and The
               Artistic Licence (see the files README, Copying, and Artistic, or perlgpl and
               perlartistic).  Larry has good reasons for NOT just using the GNU GPL.

               My personal recommendation, out of respect for Larry, Perl, and the Perl community
               at large is to state something simply like:

                Copyright (c) 1995 Your Name. All rights reserved.
                This program is free software; you can redistribute it and/or
                modify it under the same terms as Perl itself.

               This statement should at least appear in the README file. You may also wish to
               include it in a Copying file and your source files.  Remember to include the other
               words in addition to the Copyright.

           •   Give the module a version/issue/release number.

               To be fully compatible with the Exporter and MakeMaker modules you should store
               your module's version number in a non-my package variable called $VERSION.  This
               should be a positive floating point number with at least two digits after the
               decimal (i.e., hundredths, e.g, "$VERSION = "0.01"").  Don't use a "1.3.2" style
               version.  See Exporter for details.

               It may be handy to add a function or method to retrieve the number.  Use the
               number in announcements and archive file names when releasing the module
               (ModuleName-1.02.tar.Z).  See perldoc ExtUtils::MakeMaker.pm for details.

           •   How to release and distribute a module.

               If possible, register the module with CPAN. Follow the instructions and links on:

                  https://www.cpan.org/modules/04pause.html

               and upload to:

                  https://pause.perl.org/

               and notify <modules@perl.org>. This will allow anyone to install your module using
               the "cpan" tool distributed with Perl.

               By using the WWW interface you can ask the Upload Server to mirror your modules
               from your ftp or WWW site into your own directory on CPAN!

           •   Take care when changing a released module.

               Always strive to remain compatible with previous released versions.  Otherwise try
               to add a mechanism to revert to the old behavior if people rely on it.  Document
               incompatible changes.

   Guidelines for Converting Perl 4 Library Scripts into Modules
       •   There is no requirement to convert anything.

           If it ain't broke, don't fix it! Perl 4 library scripts should continue to work with
           no problems. You may need to make some minor changes (like escaping non-array @'s in
           double quoted strings) but there is no need to convert a .pl file into a Module for
           just that.

       •   Consider the implications.

           All Perl applications that make use of the script will need to be changed (slightly)
           if the script is converted into a module.  Is it worth it unless you plan to make
           other changes at the same time?

       •   Make the most of the opportunity.

           If you are going to convert the script to a module you can use the opportunity to
           redesign the interface.  The guidelines for module creation above include many of the
           issues you should consider.

       •   The pl2pm utility will get you started.

           This utility will read *.pl files (given as parameters) and write corresponding *.pm
           files. The pl2pm utilities does the following:

           •         Adds the standard Module prologue lines

           •         Converts package specifiers from ' to ::

           •         Converts die(...) to croak(...)

           •         Several other minor changes

           Being a mechanical process pl2pm is not bullet proof. The converted code will need
           careful checking, especially any package statements.  Don't delete the original .pl
           file till the new .pm one works!

   Guidelines for Reusing Application Code
       •   Complete applications rarely belong in the Perl Module Library.

       •   Many applications contain some Perl code that could be reused.

           Help save the world! Share your code in a form that makes it easy to reuse.

       •   Break-out the reusable code into one or more separate module files.

       •   Take the opportunity to reconsider and redesign the interfaces.

       •   In some cases the 'application' can then be reduced to a small

           fragment of code built on top of the reusable modules. In these cases the application
           could invoked as:

                % perl -e 'use Module::Name; method(@ARGV)' ...
           or
                % perl -mModule::Name ...    (in perl5.002 or higher)

NOTE

       Perl does not enforce private and public parts of its modules as you may have been used to
       in other languages like C++, Ada, or Modula-17.  Perl doesn't have an infatuation with
       enforced privacy.  It would prefer that you stayed out of its living room because you
       weren't invited, not because it has a shotgun.

       The module and its user have a contract, part of which is common law, and part of which is
       "written".  Part of the common law contract is that a module doesn't pollute any namespace
       it wasn't asked to.  The written contract for the module (A.K.A. documentation) may make
       other provisions.  But then you know when you "use RedefineTheWorld" that you're
       redefining the world and willing to take the consequences.