PERLMODLIB(1) Perl Programmers Reference Guide PERLMODLIB(1)

PERLMODLIB(1) Perl Programmers Reference Guide PERLMODLIB(1) #

PERLMODLIB(1) Perl Programmers Reference Guide PERLMODLIB(1)

NNAAMMEE #

 perlmodlib - constructing new Perl modules and finding existing ones

TTHHEE PPEERRLL MMOODDUULLEE LLIIBBRRAARRYY #

 Many modules are included in the Perl distribution.  These are described
 below, and all end in _._p_m.  You may discover compiled library files
 (usually ending in _._s_o) or small pieces of modules to be autoloaded
 (ending in _._a_l); these were automatically generated by the installation
 process.  You may also discover files in the library directory that end
 in either _._p_l or _._p_h.  These are old libraries supplied so that old
 programs that use them still run.  The _._p_l files will all eventually be
 converted into standard modules, and the _._p_h files made by hh22pphh will
 probably end up as extension modules made by hh22xxss.  (Some _._p_h values may
 already be available through the POSIX, Errno, or Fcntl modules.)  The
 ppll22ppmm file in the distribution may help in your conversion, but it's just
 a mechanical process and therefore far from bulletproof.

PPrraaggmmaattiicc MMoodduulleess 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 _f_i_l_e 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 ssyysstteemm(()).

 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 ssoorrtt(()) 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

SSttaannddaarrdd MMoodduulleess 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 or zlib-ng 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

 Configure   Provide auto-configuration utilities

 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 ssttaatt(()) 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 ooppeenn22(())

 IPC::Open3  Open a process for reading, writing, and error handling using
             ooppeenn33(())

 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

 OpenBSD::Pledge
             Perl interface to OpenBSD pplleeddggee(2)

 OpenBSD::Unveil
             Perl interface to OpenBSD uunnvveeiill(2)

 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 ssyysslloogg(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::ReadKey
             A perl module for simple terminal control

 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 eexxppaanndd(1) and uunneexxppaanndd(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 ggmmttiimmee(()) function

 Time::localtime
             By-name interface to Perl's built-in llooccaallttiimmee(()) 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 _a_l_l 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 mmaann(1) command.
 If you do not have a ffiinndd program, you can use the Perl ffiinndd22ppeerrll program
 instead, which generates Perl code as output you can run through perl.
 If you have a mmaann program but it doesn't find your modules, you'll have
 to fix your manpath.  See perl for details.  If you have no system mmaann
 command, you might try the ppeerrllddoocc 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.)

EExxtteennssiioonn MMoodduulleess 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.

CCPPAANN #

 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/>

MMoodduulleess:: CCrreeaattiioonn,, UUssee,, aanndd AAbbuussee (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 _._p_m file is required to exist.  See perlsub,
 perlobj, and AutoLoader for details about the AUTOLOAD mechanism.

GGuuiiddeelliinneess ffoorr MMoodduullee CCrreeaattiioonn • 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 --ww.

     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 --ww.

     Follow the guidelines in perlstyle.

     Always use --ww.

 •   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.

GGuuiiddeelliinneess ffoorr CCoonnvveerrttiinngg PPeerrll 44 LLiibbrraarryy SSccrriippttss iinnttoo MMoodduulleess • 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!

GGuuiiddeelliinneess ffoorr RReeuussiinngg AApppplliiccaattiioonn CCooddee • 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)

NNOOTTEE #

 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.

perl v5.36.3 2024-03-20 PERLMODLIB(1)