-*- mode: Pod; buffer-read-only: t -*-
!!!!!!!   DO NOT EDIT THIS FILE   !!!!!!!
This file is built by pod/perlmodlib.PL extracting documentation from the
Perl source files.
Any changes made here will be lost!

=head1 NAME

perlmodlib - constructing new Perl modules and finding existing ones

=head1 THE PERL MODULE LIBRARY

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

=head2 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 C<use>, or C<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
C<$^H> hints variable.  Others affect the current package instead,
like C<use vars> and C<use subs>, which allow you to predeclare a
variables or subroutines within a particular I<file> rather than
just a block.  Such declarations are effective for the entire file
for which they were declared.  You cannot rescind them with C<no
vars> or C<no subs>.

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

=over 12

=item attributes

Get/set subroutine or variable attributes

=item autodie

Replace functions with ones that succeed or die with lexical scope

=item autodie::exception

Exceptions from autodying functions.

=item autodie::exception::system

Exceptions from autodying system().

=item autodie::hints

Provide hints about user subroutines to autodie

=item autodie::skip

Skip a package when throwing autodie exceptions

=item autouse

Postpone load of modules until a function is used

=item base

Establish an ISA relationship with base classes at compile time

=item bigfloat

Transparent big floating point number support for Perl

=item bigint

Transparent big integer support for Perl

=item bignum

Transparent big number support for Perl

=item bigrat

Transparent big rational number support for Perl

=item blib

Use MakeMaker's uninstalled version of a package

=item builtin

Import built-in utility functions

=item bytes

Expose the individual bytes of characters

=item charnames

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

=item constant

Declare constants

=item deprecate

Perl pragma for deprecating the inclusion of a module in core

=item diagnostics

Produce verbose warning diagnostics

=item encoding

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

=item encoding::warnings

Warn on implicit encoding conversions

=item experimental

Experimental features made easy

=item feature

Enable new features

=item fields

Compile-time class fields

=item filetest

Control the filetest permission operators

=item if

C<use> a Perl module if a condition holds

=item integer

Use integer arithmetic instead of floating point

=item less

Request less of something

=item lib

Manipulate @INC at compile time

=item locale

Use or avoid POSIX locales for built-in operations

=item mro

Method Resolution Order

=item ok

Alternative to Test::More::use_ok

=item open

Set default PerlIO layers for input and output

=item ops

Restrict unsafe operations when compiling

=item overload

Package for overloading Perl operations

=item overloading

Lexically control overloading

=item parent

Establish an ISA relationship with base classes at compile time

=item re

Alter regular expression behaviour

=item sigtrap

Enable simple signal handling

=item sort

Control sort() behaviour

=item stable

Experimental features made easy, once we know they're stable

=item strict

Restrict unsafe constructs

=item subs

Predeclare subroutine names

=item threads

Perl interpreter-based threads

=item threads::shared

Perl extension for sharing data structures between threads

=item utf8

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

=item vars

Predeclare global variable names

=item version

Perl extension for Version Objects

=item vmsish

Control VMS-specific language features

=item warnings

Control optional warnings

=item warnings::register

Warnings import function


=back

=head2 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.

=over 12

=item Amiga::ARexx

Perl extension for ARexx support

=item Amiga::Exec

Perl extension for low level amiga support

=item AnyDBM_File

Provide framework for multiple DBMs

=item App::Cpan

Easily interact with CPAN from the command line

=item App::Prove

Implements the C<prove> command.

=item App::Prove::State

State storage for the C<prove> command.

=item App::Prove::State::Result

Individual test suite results.

=item App::Prove::State::Result::Test

Individual test results.

=item Archive::Tar

Module for manipulations of tar archives

=item Archive::Tar::File

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

=item Attribute::Handlers

Simpler definition of attribute handlers

=item AutoLoader

Load subroutines only on demand

=item AutoSplit

Split a package for autoloading

=item B

The Perl Compiler Backend

=item B::Concise

Walk Perl syntax tree, printing concise info about ops

=item B::Deparse

Perl compiler backend to produce perl code

=item B::Op_private

OP op_private flag definitions

=item B::Showlex

Show lexical variables used in functions or files

=item B::Terse

Walk Perl syntax tree, printing terse info about ops

=item B::Xref

Generates cross reference reports for Perl programs

=item Benchmark

Benchmark running times of Perl code

=item C<IO::Socket::IP>

Family-neutral IP socket supporting both IPv4 and IPv6

=item C<Socket>

Networking constants and support functions

=item CORE

Namespace for Perl's core routines

=item CPAN

Query, download and build perl modules from CPAN sites

=item CPAN::API::HOWTO

A recipe book for programming with CPAN.pm

=item CPAN::Debug

Internal debugging for CPAN.pm

=item CPAN::Distroprefs

Read and match distroprefs

=item CPAN::FirstTime

Utility for CPAN::Config file Initialization

=item CPAN::HandleConfig

Internal configuration handling for CPAN.pm

=item CPAN::Kwalify

Interface between CPAN.pm and Kwalify.pm

=item CPAN::Meta

The distribution metadata for a CPAN dist

=item CPAN::Meta::Converter

Convert CPAN distribution metadata structures

=item CPAN::Meta::Feature

An optional feature provided by a CPAN distribution

=item CPAN::Meta::History

History of CPAN Meta Spec changes

=item CPAN::Meta::History::Meta_1_0

Version 1.0 metadata specification for META.yml

=item CPAN::Meta::History::Meta_1_1

Version 1.1 metadata specification for META.yml

=item CPAN::Meta::History::Meta_1_2

Version 1.2 metadata specification for META.yml

=item CPAN::Meta::History::Meta_1_3

Version 1.3 metadata specification for META.yml

=item CPAN::Meta::History::Meta_1_4

Version 1.4 metadata specification for META.yml

=item CPAN::Meta::Merge

Merging CPAN Meta fragments

=item CPAN::Meta::Prereqs

A set of distribution prerequisites by phase and type

=item CPAN::Meta::Requirements

A set of version requirements for a CPAN dist

=item CPAN::Meta::Spec

Specification for CPAN distribution metadata

=item CPAN::Meta::Validator

Validate CPAN distribution metadata structures

=item CPAN::Meta::YAML

Read and write a subset of YAML for CPAN Meta files

=item CPAN::Nox

Wrapper around CPAN.pm without using any XS module

=item CPAN::Plugin

Base class for CPAN shell extensions

=item CPAN::Plugin::Specfile

Proof of concept implementation of a trivial CPAN::Plugin

=item CPAN::Queue

Internal queue support for CPAN.pm

=item CPAN::Tarzip

Internal handling of tar archives for CPAN.pm

=item CPAN::Version

Utility functions to compare CPAN versions

=item Carp

Alternative warn and die for modules

=item Class::Struct

Declare struct-like datatypes as Perl classes

=item Compress::Raw::Bzip2

Low-Level Interface to bzip2 compression library

=item Compress::Raw::Zlib

Low-Level Interface to zlib or zlib-ng compression library

=item Compress::Zlib

Interface to zlib compression library

=item Config

Access Perl configuration information

=item Config::Extensions

Hash lookup of which core extensions were built.

=item Config::Perl::V

Structured data retrieval of perl -V output

=item Cwd

Get pathname of current working directory

=item DB

Programmatic interface to the Perl debugging API

=item DBM_Filter

Filter DBM keys/values 

=item DBM_Filter::compress

Filter for DBM_Filter

=item DBM_Filter::encode

Filter for DBM_Filter

=item DBM_Filter::int32

Filter for DBM_Filter

=item DBM_Filter::null

Filter for DBM_Filter

=item DBM_Filter::utf8

Filter for DBM_Filter

=item DB_File

Perl5 access to Berkeley DB version 1.x

=item Data::Dumper

Stringified perl data structures, suitable for both printing and C<eval>

=item Devel::PPPort

Perl/Pollution/Portability

=item Devel::Peek

A data debugging tool for the XS programmer

=item Devel::SelfStubber

Generate stubs for a SelfLoading module

=item Digest

Modules that calculate message digests

=item Digest::MD5

Perl interface to the MD5 Algorithm

=item Digest::SHA

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

=item Digest::base

Digest base class

=item Digest::file

Calculate digests of files

=item DirHandle

(obsolete) supply object methods for directory handles

=item Dumpvalue

Provides screen dump of Perl data.

=item DynaLoader

Dynamically load C libraries into Perl code

=item Encode

Character encodings in Perl

=item Encode::Alias

Alias definitions to encodings

=item Encode::Byte

Single Byte Encodings

=item Encode::CJKConstants

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

=item Encode::CN

China-based Chinese Encodings

=item Encode::CN::HZ

Internally used by Encode::CN

=item Encode::Config

Internally used by Encode

=item Encode::EBCDIC

EBCDIC Encodings

=item Encode::Encoder

Object Oriented Encoder

=item Encode::Encoding

Encode Implementation Base Class

=item Encode::GSM0338

ETSI GSM 03.38 Encoding

=item Encode::Guess

Guesses encoding from data

=item Encode::JP

Japanese Encodings

=item Encode::JP::H2Z

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

=item Encode::JP::JIS7

Internally used by Encode::JP

=item Encode::KR

Korean Encodings

=item Encode::KR::2022_KR

Internally used by Encode::KR

=item Encode::MIME::Header

MIME encoding for an unstructured email header

=item Encode::MIME::Name

Internally used by Encode

=item Encode::PerlIO

A detailed document on Encode and PerlIO

=item Encode::Supported

Encodings supported by Encode

=item Encode::Symbol

Symbol Encodings

=item Encode::TW

Taiwan-based Chinese Encodings

=item Encode::Unicode

Various Unicode Transformation Formats

=item Encode::Unicode::UTF7

UTF-7 encoding

=item English

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

=item Env

Perl module that imports environment variables as scalars or arrays

=item Errno

System errno constants

=item Exporter

Implements default import method for modules

=item Exporter::Heavy

Exporter guts

=item ExtUtils::CBuilder

Compile and link C code for Perl modules

=item ExtUtils::CBuilder::Platform::Windows

Builder class for Windows platforms

=item ExtUtils::Command

Utilities to replace common UNIX commands in Makefiles etc.

=item ExtUtils::Command::MM

Commands for the MM's to use in Makefiles

=item ExtUtils::Constant

Generate XS code to import C header constants

=item ExtUtils::Constant::Base

Base class for ExtUtils::Constant objects

=item ExtUtils::Constant::Utils

Helper functions for ExtUtils::Constant

=item ExtUtils::Constant::XS

Generate C code for XS modules' constants.

=item ExtUtils::Embed

Utilities for embedding Perl in C/C++ applications

=item ExtUtils::Install

Install files from here to there

=item ExtUtils::Installed

Inventory management of installed modules

=item ExtUtils::Liblist

Determine libraries to use and how to use them

=item ExtUtils::MM

OS adjusted ExtUtils::MakeMaker subclass

=item ExtUtils::MM_AIX

AIX specific subclass of ExtUtils::MM_Unix

=item ExtUtils::MM_Any

Platform-agnostic MM methods

=item ExtUtils::MM_BeOS

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

=item ExtUtils::MM_Cygwin

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

=item ExtUtils::MM_DOS

DOS specific subclass of ExtUtils::MM_Unix

=item ExtUtils::MM_Darwin

Special behaviors for OS X

=item ExtUtils::MM_MacOS

Once produced Makefiles for MacOS Classic

=item ExtUtils::MM_NW5

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

=item ExtUtils::MM_OS2

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

=item ExtUtils::MM_OS390

OS390 specific subclass of ExtUtils::MM_Unix

=item ExtUtils::MM_QNX

QNX specific subclass of ExtUtils::MM_Unix

=item ExtUtils::MM_UWIN

U/WIN specific subclass of ExtUtils::MM_Unix

=item ExtUtils::MM_Unix

Methods used by ExtUtils::MakeMaker

=item ExtUtils::MM_VMS

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

=item ExtUtils::MM_VOS

VOS specific subclass of ExtUtils::MM_Unix

=item ExtUtils::MM_Win32

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

=item ExtUtils::MM_Win95

Method to customize MakeMaker for Win9X

=item ExtUtils::MY

ExtUtils::MakeMaker subclass for customization

=item ExtUtils::MakeMaker

Create a module Makefile

=item ExtUtils::MakeMaker::Config

Wrapper around Config.pm

=item ExtUtils::MakeMaker::FAQ

Frequently Asked Questions About MakeMaker

=item ExtUtils::MakeMaker::Locale

Bundled Encode::Locale

=item ExtUtils::MakeMaker::Tutorial

Writing a module with MakeMaker

=item ExtUtils::Manifest

Utilities to write and check a MANIFEST file

=item ExtUtils::Miniperl

Write the C code for miniperlmain.c and perlmain.c

=item ExtUtils::Mkbootstrap

Make a bootstrap file for use by DynaLoader

=item ExtUtils::Mksymlists

Write linker options files for dynamic extension

=item ExtUtils::PL2Bat

Batch file creation to run perl scripts on Windows

=item ExtUtils::Packlist

Manage .packlist files

=item ExtUtils::ParseXS

Converts Perl XS code into C code

=item ExtUtils::ParseXS::Constants

Initialization values for some globals

=item ExtUtils::ParseXS::Eval

Clean package to evaluate code in

=item ExtUtils::ParseXS::Utilities

Subroutines used with ExtUtils::ParseXS

=item ExtUtils::Typemaps

Read/Write/Modify Perl/XS typemap files

=item ExtUtils::Typemaps::Cmd

Quick commands for handling typemaps

=item ExtUtils::Typemaps::InputMap

Entry in the INPUT section of a typemap

=item ExtUtils::Typemaps::OutputMap

Entry in the OUTPUT section of a typemap

=item ExtUtils::Typemaps::Type

Entry in the TYPEMAP section of a typemap

=item ExtUtils::XSSymSet

Keep sets of symbol names palatable to the VMS linker

=item ExtUtils::testlib

Add blib/* directories to @INC

=item Fatal

Replace functions with equivalents which succeed or die

=item Fcntl

Load the C Fcntl.h defines

=item File::Basename

Parse file paths into directory, filename and suffix.

=item File::Compare

Compare files or filehandles

=item File::Copy

Copy files or filehandles

=item File::DosGlob

DOS like globbing and then some

=item File::Fetch

A generic file fetching mechanism

=item File::Find

Traverse a directory tree.

=item File::Glob

Perl extension for BSD glob routine

=item File::GlobMapper

Extend File Glob to Allow Input and Output Files

=item File::Path

Create or remove directory trees

=item File::Spec

Portably perform operations on file names

=item File::Spec::AmigaOS

File::Spec for AmigaOS

=item File::Spec::Cygwin

Methods for Cygwin file specs

=item File::Spec::Epoc

Methods for Epoc file specs

=item File::Spec::Functions

Portably perform operations on file names

=item File::Spec::Mac

File::Spec for Mac OS (Classic)

=item File::Spec::OS2

Methods for OS/2 file specs

=item File::Spec::Unix

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

=item File::Spec::VMS

Methods for VMS file specs

=item File::Spec::Win32

Methods for Win32 file specs

=item File::Temp

Return name and handle of a temporary file safely

=item File::stat

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

=item FileCache

Keep more files open than the system permits

=item FileHandle

Supply object methods for filehandles

=item Filter::Simple

Simplified source filtering

=item Filter::Util::Call

Perl Source Filter Utility Module

=item FindBin

Locate directory of original perl script

=item GDBM_File

Perl5 access to the gdbm library.

=item Getopt::Long

Extended processing of command line options

=item Getopt::Std

Process single-character switches with switch clustering

=item HTTP::Tiny

A small, simple, correct HTTP/1.1 client

=item Hash::Util

A selection of general-utility hash subroutines

=item Hash::Util::FieldHash

Support for Inside-Out Classes

=item I18N::Collate

Compare 8-bit scalar data according to the current locale

=item I18N::LangTags

Functions for dealing with RFC3066-style language tags

=item I18N::LangTags::Detect

Detect the user's language preferences

=item I18N::LangTags::List

Tags and names for human languages

=item I18N::Langinfo

Query locale information

=item IO

Load various IO modules

=item IO::Compress::Base

Base Class for IO::Compress modules

=item IO::Compress::Bzip2

Write bzip2 files/buffers

=item IO::Compress::Deflate

Write RFC 1950 files/buffers

=item IO::Compress::FAQ

Frequently Asked Questions about IO::Compress

=item IO::Compress::Gzip

Write RFC 1952 files/buffers

=item IO::Compress::RawDeflate

Write RFC 1951 files/buffers

=item IO::Compress::Zip

Write zip files/buffers

=item IO::Dir

Supply object methods for directory handles

=item IO::File

Supply object methods for filehandles

=item IO::Handle

Supply object methods for I/O handles

=item IO::Pipe

Supply object methods for pipes

=item IO::Poll

Object interface to system poll call

=item IO::Seekable

Supply seek based methods for I/O objects

=item IO::Select

OO interface to the select system call

=item IO::Socket

Object interface to socket communications

=item IO::Socket::INET

Object interface for AF_INET domain sockets

=item IO::Socket::UNIX

Object interface for AF_UNIX domain sockets

=item IO::Uncompress::AnyInflate

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

=item IO::Uncompress::AnyUncompress

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

=item IO::Uncompress::Base

Base Class for IO::Uncompress modules

=item IO::Uncompress::Bunzip2

Read bzip2 files/buffers

=item IO::Uncompress::Gunzip

Read RFC 1952 files/buffers

=item IO::Uncompress::Inflate

Read RFC 1950 files/buffers

=item IO::Uncompress::RawInflate

Read RFC 1951 files/buffers

=item IO::Uncompress::Unzip

Read zip files/buffers

=item IO::Zlib

IO:: style interface to L<Compress::Zlib>

=item IPC::Cmd

Finding and running system commands made easy

=item IPC::Msg

SysV Msg IPC object class

=item IPC::Open2

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

=item IPC::Open3

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

=item IPC::Semaphore

SysV Semaphore IPC object class

=item IPC::SharedMem

SysV Shared Memory IPC object class

=item IPC::SysV

System V IPC constants and system calls

=item Internals

Reserved special namespace for internals related functions

=item JSON::PP

JSON::XS compatible pure-Perl module.

=item JSON::PP::Boolean

Dummy module providing JSON::PP::Boolean

=item List::Util

A selection of general-utility list subroutines

=item List::Util::XS

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

=item Locale::Maketext

Framework for localization

=item Locale::Maketext::Cookbook

Recipes for using Locale::Maketext

=item Locale::Maketext::Guts

Deprecated module to load Locale::Maketext utf8 code

=item Locale::Maketext::GutsLoader

Deprecated module to load Locale::Maketext utf8 code

=item Locale::Maketext::Simple

Simple interface to Locale::Maketext::Lexicon

=item Locale::Maketext::TPJ13

Article about software localization

=item MIME::Base64

Encoding and decoding of base64 strings

=item MIME::QuotedPrint

Encoding and decoding of quoted-printable strings

=item Math::BigFloat

Arbitrary size floating point math package

=item Math::BigInt

Arbitrary size integer math package

=item Math::BigInt::Calc

Pure Perl module to support Math::BigInt

=item Math::BigInt::FastCalc

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

=item Math::BigInt::Lib

Virtual parent class for Math::BigInt libraries

=item Math::BigRat

Arbitrary size rational number math package

=item Math::Complex

Complex numbers and associated mathematical functions

=item Math::Trig

Trigonometric functions

=item Memoize

Make functions faster by trading space for time

=item Memoize::AnyDBM_File

Glue to provide EXISTS for AnyDBM_File for Storable use

=item Memoize::Expire

Plug-in module for automatic expiration of memoized values

=item Memoize::NDBM_File

Glue to provide EXISTS for NDBM_File for Storable use

=item Memoize::SDBM_File

DEPRECATED compability shim

=item Memoize::Storable

Store Memoized data in Storable database

=item Module::CoreList

What modules shipped with versions of perl

=item Module::CoreList::Utils

What utilities shipped with versions of perl

=item Module::Load

Runtime require of both modules and files

=item Module::Load::Conditional

Looking up module information / loading at runtime

=item Module::Loaded

Mark modules as loaded or unloaded

=item Module::Metadata

Gather package and POD information from perl module files

=item NDBM_File

Tied access to ndbm files

=item NEXT

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

=item Net::Cmd

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

=item Net::Config

Local configuration data for libnet

=item Net::Domain

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

=item Net::FTP

FTP Client class

=item Net::FTP::dataconn

FTP Client data connection class

=item Net::NNTP

NNTP Client class

=item Net::Netrc

OO interface to users netrc file

=item Net::POP3

Post Office Protocol 3 Client class (RFC1939)

=item Net::Ping

Check a remote host for reachability

=item Net::SMTP

Simple Mail Transfer Protocol Client

=item Net::Time

Time and daytime network client interface

=item Net::hostent

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

=item Net::libnetFAQ

Libnet Frequently Asked Questions

=item Net::netent

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

=item Net::protoent

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

=item Net::servent

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

=item O

Generic interface to Perl Compiler backends

=item ODBM_File

Tied access to odbm files

=item Opcode

Disable named opcodes when compiling perl code

=item POSIX

Perl interface to IEEE Std 1003.1

=item Params::Check

A generic input parsing/checking mechanism.

=item Parse::CPAN::Meta

Parse META.yml and META.json CPAN metadata files

=item Perl::OSType

Map Perl operating system names to generic types

=item PerlIO

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

=item PerlIO::encoding

Encoding layer

=item PerlIO::mmap

Memory mapped IO

=item PerlIO::scalar

In-memory IO, scalar IO

=item PerlIO::via

Helper class for PerlIO layers implemented in perl

=item PerlIO::via::QuotedPrint

PerlIO layer for quoted-printable strings

=item Pod::Checker

Check pod documents for syntax errors

=item Pod::Escapes

For resolving Pod EE<lt>...E<gt> sequences

=item Pod::Functions

Group Perl's functions a la perlfunc.pod

=item Pod::Html

Module to convert pod files to HTML

=item Pod::Html::Util

Helper functions for Pod-Html

=item Pod::Man

Convert POD data to formatted *roff input

=item Pod::ParseLink

Parse an LE<lt>E<gt> formatting code in POD text

=item Pod::Perldoc

Look up Perl documentation in Pod format.

=item Pod::Perldoc::BaseTo

Base for Pod::Perldoc formatters

=item Pod::Perldoc::GetOptsOO

Customized option parser for Pod::Perldoc

=item Pod::Perldoc::ToANSI

Render Pod with ANSI color escapes 

=item Pod::Perldoc::ToChecker

Let Perldoc check Pod for errors

=item Pod::Perldoc::ToMan

Let Perldoc render Pod as man pages

=item Pod::Perldoc::ToNroff

Let Perldoc convert Pod to nroff

=item Pod::Perldoc::ToPod

Let Perldoc render Pod as ... Pod!

=item Pod::Perldoc::ToRtf

Let Perldoc render Pod as RTF

=item Pod::Perldoc::ToTerm

Render Pod with terminal escapes

=item Pod::Perldoc::ToText

Let Perldoc render Pod as plaintext

=item Pod::Perldoc::ToTk

Let Perldoc use Tk::Pod to render Pod

=item Pod::Perldoc::ToXml

Let Perldoc render Pod as XML

=item Pod::Simple

Framework for parsing Pod

=item Pod::Simple::Checker

Check the Pod syntax of a document

=item Pod::Simple::Debug

Put Pod::Simple into trace/debug mode

=item Pod::Simple::DumpAsText

Dump Pod-parsing events as text

=item Pod::Simple::DumpAsXML

Turn Pod into XML

=item Pod::Simple::HTML

Convert Pod to HTML

=item Pod::Simple::HTMLBatch

Convert several Pod files to several HTML files

=item Pod::Simple::JustPod

Just the Pod, the whole Pod, and nothing but the Pod

=item Pod::Simple::LinkSection

Represent "section" attributes of L codes

=item Pod::Simple::Methody

Turn Pod::Simple events into method calls

=item Pod::Simple::PullParser

A pull-parser interface to parsing Pod

=item Pod::Simple::PullParserEndToken

End-tokens from Pod::Simple::PullParser

=item Pod::Simple::PullParserStartToken

Start-tokens from Pod::Simple::PullParser

=item Pod::Simple::PullParserTextToken

Text-tokens from Pod::Simple::PullParser

=item Pod::Simple::PullParserToken

Tokens from Pod::Simple::PullParser

=item Pod::Simple::RTF

Format Pod as RTF

=item Pod::Simple::Search

Find POD documents in directory trees

=item Pod::Simple::SimpleTree

Parse Pod into a simple parse tree 

=item Pod::Simple::Subclassing

Write a formatter as a Pod::Simple subclass

=item Pod::Simple::Text

Format Pod as plaintext

=item Pod::Simple::TextContent

Get the text content of Pod

=item Pod::Simple::XHTML

Format Pod as validating XHTML

=item Pod::Simple::XMLOutStream

Turn Pod into XML

=item Pod::Text

Convert POD data to formatted text

=item Pod::Text::Color

Convert POD data to formatted color ASCII text

=item Pod::Text::Overstrike

Convert POD data to formatted overstrike text

=item Pod::Text::Termcap

Convert POD data to ASCII text with format escapes

=item Pod::Usage

Extracts POD documentation and shows usage information

=item SDBM_File

Tied access to sdbm files

=item Safe

Compile and execute code in restricted compartments

=item Scalar::Util

A selection of general-utility scalar subroutines

=item Search::Dict

Look - search for key in dictionary file

=item SelectSaver

Save and restore selected file handle

=item SelfLoader

Load functions only on demand

=item Storable

Persistence for Perl data structures

=item Sub::Util

A selection of utility subroutines for subs and CODE references

=item Symbol

Manipulate Perl symbols and their names

=item Sys::Hostname

Try every conceivable way to get hostname

=item Sys::Syslog

Perl interface to the UNIX syslog(3) calls

=item Sys::Syslog::Win32

Win32 support for Sys::Syslog

=item TAP::Base

Base class that provides common functionality to L<TAP::Parser>

=item TAP::Formatter::Base

Base class for harness output delegates

=item TAP::Formatter::Color

Run Perl test scripts with color

=item TAP::Formatter::Console

Harness output delegate for default console output

=item TAP::Formatter::Console::ParallelSession

Harness output delegate for parallel console output

=item TAP::Formatter::Console::Session

Harness output delegate for default console output

=item TAP::Formatter::File

Harness output delegate for file output

=item TAP::Formatter::File::Session

Harness output delegate for file output

=item TAP::Formatter::Session

Abstract base class for harness output delegate 

=item TAP::Harness

Run test scripts with statistics

=item TAP::Harness::Env

Parsing harness related environmental variables where appropriate

=item TAP::Object

Base class that provides common functionality to all C<TAP::*> modules

=item TAP::Parser

Parse L<TAP|Test::Harness::TAP> output

=item TAP::Parser::Aggregator

Aggregate TAP::Parser results

=item TAP::Parser::Grammar

A grammar for the Test Anything Protocol.

=item TAP::Parser::Iterator

Base class for TAP source iterators

=item TAP::Parser::Iterator::Array

Iterator for array-based TAP sources

=item TAP::Parser::Iterator::Process

Iterator for process-based TAP sources

=item TAP::Parser::Iterator::Stream

Iterator for filehandle-based TAP sources

=item TAP::Parser::IteratorFactory

Figures out which SourceHandler objects to use for a given Source

=item TAP::Parser::Multiplexer

Multiplex multiple TAP::Parsers

=item TAP::Parser::Result

Base class for TAP::Parser output objects

=item TAP::Parser::Result::Bailout

Bailout result token.

=item TAP::Parser::Result::Comment

Comment result token.

=item TAP::Parser::Result::Plan

Plan result token.

=item TAP::Parser::Result::Pragma

TAP pragma token.

=item TAP::Parser::Result::Test

Test result token.

=item TAP::Parser::Result::Unknown

Unknown result token.

=item TAP::Parser::Result::Version

TAP syntax version token.

=item TAP::Parser::Result::YAML

YAML result token.

=item TAP::Parser::ResultFactory

Factory for creating TAP::Parser output objects

=item TAP::Parser::Scheduler

Schedule tests during parallel testing

=item TAP::Parser::Scheduler::Job

A single testing job.

=item TAP::Parser::Scheduler::Spinner

A no-op job.

=item TAP::Parser::Source

A TAP source & meta data about it

=item TAP::Parser::SourceHandler

Base class for different TAP source handlers

=item TAP::Parser::SourceHandler::Executable

Stream output from an executable TAP source

=item TAP::Parser::SourceHandler::File

Stream TAP from a text file.

=item TAP::Parser::SourceHandler::Handle

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

=item TAP::Parser::SourceHandler::Perl

Stream TAP from a Perl executable

=item TAP::Parser::SourceHandler::RawTAP

Stream output from raw TAP in a scalar/array ref.

=item TAP::Parser::YAMLish::Reader

Read YAMLish data from iterator

=item TAP::Parser::YAMLish::Writer

Write YAMLish data

=item Term::ANSIColor

Color screen output using ANSI escape sequences

=item Term::Cap

Perl termcap interface

=item Term::Complete

Perl word completion module

=item Term::ReadLine

Perl interface to various C<readline> packages.

=item Test

Provides a simple framework for writing test scripts

=item Test2

Framework for writing test tools that all work together.

=item Test2::API

Primary interface for writing Test2 based testing tools.

=item Test2::API::Breakage

What breaks at what version

=item Test2::API::Context

Object to represent a testing context.

=item Test2::API::Instance

Object used by Test2::API under the hood

=item Test2::API::InterceptResult

Representation of a list of events.

=item Test2::API::InterceptResult::Event

Representation of an event for use in

=item Test2::API::InterceptResult::Hub

Hub used by InterceptResult.

=item Test2::API::InterceptResult::Squasher

Encapsulation of the algorithm that

=item Test2::API::Stack

Object to manage a stack of L<Test2::Hub>

=item Test2::Event

Base class for events

=item Test2::Event::Bail

Bailout!

=item Test2::Event::Diag

Diag event type

=item Test2::Event::Encoding

Set the encoding for the output stream

=item Test2::Event::Exception

Exception event

=item Test2::Event::Fail

Event for a simple failed assertion

=item Test2::Event::Generic

Generic event type.

=item Test2::Event::Note

Note event type

=item Test2::Event::Ok

Ok event type

=item Test2::Event::Pass

Event for a simple passing assertion

=item Test2::Event::Plan

The event of a plan

=item Test2::Event::Skip

Skip event type

=item Test2::Event::Subtest

Event for subtest types

=item Test2::Event::TAP::Version

Event for TAP version.

=item Test2::Event::V2

Second generation event.

=item Test2::Event::Waiting

Tell all procs/threads it is time to be done

=item Test2::EventFacet

Base class for all event facets.

=item Test2::EventFacet::About

Facet with event details.

=item Test2::EventFacet::Amnesty

Facet for assertion amnesty.

=item Test2::EventFacet::Assert

Facet representing an assertion.

=item Test2::EventFacet::Control

Facet for hub actions and behaviors.

=item Test2::EventFacet::Error

Facet for errors that need to be shown.

=item Test2::EventFacet::Hub

Facet for the hubs an event passes through.

=item Test2::EventFacet::Info

Facet for information a developer might care about.

=item Test2::EventFacet::Info::Table

Intermediary representation of a table.

=item Test2::EventFacet::Meta

Facet for meta-data

=item Test2::EventFacet::Parent

Facet for events contains other events

=item Test2::EventFacet::Plan

Facet for setting the plan

=item Test2::EventFacet::Render

Facet that dictates how to render an event.

=item Test2::EventFacet::Trace

Debug information for events

=item Test2::Formatter

Namespace for formatters.

=item Test2::Formatter::TAP

Standard TAP formatter

=item Test2::Hub

The conduit through which all events flow.

=item Test2::Hub::Interceptor

Hub used by interceptor to grab results.

=item Test2::Hub::Interceptor::Terminator

Exception class used by

=item Test2::Hub::Subtest

Hub used by subtests

=item Test2::IPC

Turn on IPC for threading or forking support.

=item Test2::IPC::Driver

Base class for Test2 IPC drivers.

=item Test2::IPC::Driver::Files

Temp dir + Files concurrency model.

=item Test2::Tools::Tiny

Tiny set of tools for unfortunate souls who cannot use

=item Test2::Transition

Transition notes when upgrading to Test2

=item Test2::Util

Tools used by Test2 and friends.

=item Test2::Util::ExternalMeta

Allow third party tools to safely attach meta-data

=item Test2::Util::Facets2Legacy

Convert facet data to the legacy event API.

=item Test2::Util::HashBase

Build hash based classes.

=item Test2::Util::Trace

Legacy wrapper fro L<Test2::EventFacet::Trace>.

=item Test::Builder

Backend for building test libraries

=item Test::Builder::Formatter

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

=item Test::Builder::IO::Scalar

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

=item Test::Builder::Module

Base class for test modules

=item Test::Builder::Tester

Test testsuites that have been built with

=item Test::Builder::Tester::Color

Turn on colour in Test::Builder::Tester

=item Test::Builder::TodoDiag

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

=item Test::Harness

Run Perl standard test scripts with statistics

=item Test::Harness::Beyond

Beyond make test

=item Test::More

Yet another framework for writing test scripts

=item Test::Simple

Basic utilities for writing tests.

=item Test::Tester

Ease testing test modules built with Test::Builder

=item Test::Tester::Capture

Help testing test modules built with Test::Builder

=item Test::Tester::CaptureRunner

Help testing test modules built with Test::Builder

=item Test::Tutorial

A tutorial about writing really basic tests

=item Test::use::ok

Alternative to Test::More::use_ok

=item Text::Abbrev

Abbrev - create an abbreviation table from a list

=item Text::Balanced

Extract delimited text sequences from strings.

=item Text::ParseWords

Parse text into an array of tokens or array of arrays

=item Text::Tabs

Expand and unexpand tabs like unix expand(1) and unexpand(1)

=item Text::Wrap

Line wrapping to form simple paragraphs

=item Thread

Manipulate threads in Perl (for old code only)

=item Thread::Queue

Thread-safe queues

=item Thread::Semaphore

Thread-safe semaphores

=item Tie::Array

Base class for tied arrays

=item Tie::File

Access the lines of a disk file via a Perl array

=item Tie::Handle

Base class definitions for tied handles

=item Tie::Hash

Base class definitions for tied hashes

=item Tie::Hash::NamedCapture

Named regexp capture buffers

=item Tie::Memoize

Add data to hash when needed

=item Tie::RefHash

Use references as hash keys

=item Tie::Scalar

Base class definitions for tied scalars

=item Tie::StdHandle

Base class definitions for tied handles

=item Tie::SubstrHash

Fixed-table-size, fixed-key-length hashing

=item Time::HiRes

High resolution alarm, sleep, gettimeofday, interval timers

=item Time::Local

Efficiently compute time from local and GMT time

=item Time::Piece

Object Oriented time objects

=item Time::Seconds

A simple API to convert seconds to other date values

=item Time::gmtime

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

=item Time::localtime

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

=item Time::tm

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

=item UNIVERSAL

Base class for ALL classes (blessed references)

=item Unicode::Collate

Unicode Collation Algorithm

=item Unicode::Collate::CJK::Big5

Weighting CJK Unified Ideographs

=item Unicode::Collate::CJK::GB2312

Weighting CJK Unified Ideographs

=item Unicode::Collate::CJK::JISX0208

Weighting JIS KANJI for Unicode::Collate

=item Unicode::Collate::CJK::Korean

Weighting CJK Unified Ideographs

=item Unicode::Collate::CJK::Pinyin

Weighting CJK Unified Ideographs

=item Unicode::Collate::CJK::Stroke

Weighting CJK Unified Ideographs

=item Unicode::Collate::CJK::Zhuyin

Weighting CJK Unified Ideographs

=item Unicode::Collate::Locale

Linguistic tailoring for DUCET via Unicode::Collate

=item Unicode::Normalize

Unicode Normalization Forms

=item Unicode::UCD

Unicode character database

=item User::grent

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

=item User::pwent

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

=item VMS::DCLsym

Perl extension to manipulate DCL symbols

=item VMS::Filespec

Convert between VMS and Unix file specification syntax

=item VMS::Stdio

Standard I/O functions via VMS extensions

=item Win32

Interfaces to some Win32 API Functions

=item Win32API::File

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

=item Win32CORE

Win32 CORE function stubs

=item XS::APItest

Test the perl C API

=item XS::Typemap

Module to test the XS typemaps distributed with perl

=item XSLoader

Dynamically load C libraries into Perl code

=item autodie::Scope::Guard

Wrapper class for calling subs at end of scope

=item autodie::Scope::GuardStack

Hook stack for managing scopes via %^H

=item autodie::Util

Internal Utility subroutines for autodie and Fatal

=item version::Internals

Perl extension for Version Objects


=back

To find out I<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 C<PERL5LIB>,
C<PERLLIB>, and C<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 B<find>
program, you can use the Perl B<find2perl> program instead, which
generates Perl code as output you can run through perl.  If you
have a B<man> program but it doesn't find your modules, you'll have
to fix your manpath.  See L<perl> for details.  If you have no
system B<man> command, you might try the B<perldoc> program.

Note also that the command C<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.)

=head2 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.

=head1 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:

=over

=item *

Language Extensions and Documentation Tools

=item *

Development Support

=item *

Operating System Interfaces

=item *

Networking, Device Control (modems) and InterProcess Communication

=item *

Data Types and Data Type Utilities

=item *

Database Interfaces

=item *

User Interfaces

=item *

Interfaces to / Emulations of Other Programming Languages

=item *

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

=item *

String Processing, Language Text Processing, Parsing, and Searching

=item *

Option, Argument, Parameter, and Configuration File Processing

=item *

Internationalization and Locale

=item *

Authentication, Security, and Encryption

=item *

World Wide Web, HTML, HTTP, CGI, MIME

=item *

Server and Daemon Utilities

=item *

Archiving and Compression

=item *

Images, Pixmap and Bitmap Manipulation, Drawing, and Graphing

=item *

Mail and Usenet News

=item *

Control Flow Utilities (callbacks and exceptions etc)

=item *

File Handle and Input/Output Stream Utilities

=item *

Miscellaneous Modules

=back

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

=head1 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 F<.pm> file is required to
exist.  See L<perlsub>, L<perlobj>, and L<AutoLoader> for details about
the AUTOLOAD mechanism.

=head2 Guidelines for Module Creation

=over 4

=item  *

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.

=item  *

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

Try to C<use warnings;> (or C<use warnings qw(...);>).
Remember that you can add C<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: C<die "Invalid" unless ref $ref eq 'FOO'>.
Generally you can delete the C<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 C<< $r->Class::func() >> where using C<@ISA=qw(... Class ...)> and
C<< $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
C<@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:  C<< $obj = YOURCLASS->new(); >>
into: C<< $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 B<-w>.

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

Always use B<-w>.

Follow the guidelines in L<perlstyle>.

Always use B<-w>.

=item  *

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., C<< $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.

=item  *

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 C<< $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:
C<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.

=item  *

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.

=item  *

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!

=item  *

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:

=over 10

=item *

A description of the module/package/extension etc.

=item *

A copyright notice - see below.

=item *

Prerequisites - what else you may need to have.

=item *

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

=item *

How to install it.

=item *

Recent changes in this release, especially incompatibilities

=item *

Changes / enhancements you plan to make in the future.

=back

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.

=over 4

=item *

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 L<perlgpl> and L<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.

=item  *

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 $VERSION.  This should be a positive floating point
number with at least two digits after the decimal (i.e., hundredths,
e.g, C<$VERSION = "0.01">).  Don't use a "1.3.2" style version.
See L<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.

=item  *

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 C<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!

=item  *

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.

=back

=back

=head2 Guidelines for Converting Perl 4 Library Scripts into Modules

=over 4

=item  *

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.

=item  *

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?

=item  *

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.

=item  *

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:

=over 10

=item *

Adds the standard Module prologue lines

=item *

Converts package specifiers from ' to ::

=item *

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

=item *

Several other minor changes

=back

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!

=back

=head2 Guidelines for Reusing Application Code

=over 4

=item  *

Complete applications rarely belong in the Perl Module Library.

=item  *

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.

=item  *

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

=item  *

Take the opportunity to reconsider and redesign the interfaces.

=item  *

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)

=back

=head1 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 C<use RedefineTheWorld> that
you're redefining the world and willing to take the consequences.

=cut

ex: set ro ft=pod:
