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perlmodlib(1) [centos man page]

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

perlmodlib - constructing new Perl modules and finding existing ones THE PERL MODULE LIBRARY
Many modules are included in the Perl distribution. These are described below, and all end in .pm. You may discover compiled library files (usually ending in .so) or small pieces of modules to be autoloaded (ending in .al); these were automatically generated by the installation process. You may also discover files in the library directory that end in either .pl or .ph. These are old libraries supplied so that old programs that use them still run. The .pl files will all eventually be converted into standard modules, and the .ph files made by h2ph will probably end up as extension modules made by h2xs. (Some .ph values may already be available through the POSIX, Errno, or Fcntl modules.) The pl2pm file in the distribution may help in your conversion, but it's just a mechanical process and therefore far from bulletproof. Pragmatic Modules They work somewhat like compiler directives (pragmata) in that they tend to affect the compilation of your program, and thus will usually work well only when used within a "use", or "no". Most of these are lexically scoped, so an inner BLOCK may countermand them by saying: no integer; no strict 'refs'; no warnings; which lasts until the end of that BLOCK. Some pragmas are lexically scoped--typically those that affect the $^H hints variable. Others affect the current package instead, like "use vars" and "use subs", which allow you to predeclare a variables or subroutines within a particular file rather than just a block. Such declarations are effective for the entire file for which they were declared. You cannot rescind them with "no vars" or "no subs". The following pragmas are defined (and have their own documentation). arybase Set indexing base via $[ attributes Get/set subroutine or variable attributes autodie Replace functions with ones that succeed or die with lexical scope autodie::exception Exceptions from autodying functions. autodie::exception::system Exceptions from autodying system(). autodie::hints Provide hints about user subroutines to autodie autouse Postpone load of modules until a function is used base Establish an ISA relationship with base classes at compile time bigint Transparent BigInteger support for Perl bignum Transparent BigNumber support for Perl bigrat Transparent BigNumber/BigRational support for Perl blib Use MakeMaker's uninstalled version of a package bytes Force byte semantics rather than character semantics charnames Access to Unicode character names and named character sequences; also define character names constant Declare constants deprecate Perl pragma for deprecating the core version of a module diagnostics Produce verbose warning diagnostics encoding Allows you to write your script in non-ascii or non-utf8 encoding::warnings Warn on implicit encoding conversions feature Enable new features fields Compile-time class fields filetest Control the filetest permission operators if "use" a Perl module if a condition holds inc::latest Use modules bundled in inc/ if they are newer than installed ones 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 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 perldoc Look up Perl documentation in Pod format. perlfaq Frequently asked questions about Perl perlfaq1 General Questions About Perl perlfaq2 Obtaining and Learning about Perl perlfaq3 Programming Tools perlfaq4 Data Manipulation perlfaq5 Files and Formats perlfaq6 Regular Expressions perlfaq7 General Perl Language Issues perlfaq8 System Interaction perlfaq9 Web, Email and Networking perlfunc Perl builtin functions perlglossary Perl Glossary perlpodspeccopy Plain Old Documentation: format specification and notes perlvarcopy Perl predefined variables perlxs XS language reference manual perlxstut Tutorial for writing XSUBs perlxstypemap Perl XS C/Perl type mapping re Alter regular expression behaviour sigtrap Enable simple signal handling sort Control sort() behaviour strict Restrict unsafe constructs subs Predeclare sub 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 (obsolete) version Perl extension for Version Objects vmsish Control VMS-specific language features warnings Control optional warnings warnings::register Warnings import function Standard Modules Standard, bundled modules are all expected to behave in a well-defined manner with respect to namespace pollution because they use the Exporter module. See their own documentation for details. It's possible that not all modules listed below are installed on your system. For example, the GDBM_File module will not be installed if you don't have the gdbm library. 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::Extract A generic archive extracting mechanism 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::Debug Walk Perl syntax tree, printing debug info about ops B::Deparse Perl compiler backend to produce perl code B::Lint Perl lint B::Lint::Debug Adds debugging stringification to B:: 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 "Socket" Networking constants and support functions CGI Handle Common Gateway Interface requests and responses CGI::Apache Backward compatibility module for CGI::Carp CGI routines for writing to the HTTPD (or other) error log CGI::Cookie Interface to HTTP Cookies CGI::Fast CGI Interface for Fast CGI CGI::Pretty Module to produce nicely formatted HTML code CGI::Push Simple Interface to Server Push CGI::Switch Backward compatibility module for defunct CGI::Switch CGI::Util Internal utilities used by CGI module 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::Debug Internal debugging for CPAN::Distroprefs Read and match distroprefs CPAN::FirstTime Utility for CPAN::Config file Initialization CPAN::HandleConfig Internal configuration handling for CPAN::Kwalify Interface between and 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::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 without using any XS module CPAN::Queue Internal queue support for CPAN::Tarzip Internal handling of tar archives for CPAN::Version Utility functions to compare CPAN versions CPANPLUS API & CLI access to the CPAN mirrors CPANPLUS::Backend Programmer's interface to CPANPLUS CPANPLUS::Backend::RV Return value objects CPANPLUS::Config Configuration defaults and heuristics for CPANPLUS CPANPLUS::Configure Configuration for CPANPLUS CPANPLUS::Dist Base class for plugins CPANPLUS::Dist::Autobundle Distribution class for installation snapshots CPANPLUS::Dist::Base Base class for custom distribution classes CPANPLUS::Dist::Build CPANPLUS plugin to install packages that use Build.PL CPANPLUS::Dist::Build::Constants Constants for CPANPLUS::Dist::Build CPANPLUS::Dist::MM Distribution class for MakeMaker related modules CPANPLUS::Dist::Sample Sample code to create your own Dist::* plugin CPANPLUS::Error Error handling for CPANPLUS CPANPLUS::FAQ CPANPLUS Frequently Asked Questions CPANPLUS::Hacking Developing CPANPLUS CPANPLUS::Internals CPANPLUS internals CPANPLUS::Internals::Extract Internals for archive extraction CPANPLUS::Internals::Fetch Internals for fetching files CPANPLUS::Internals::Report Internals for sending test reports CPANPLUS::Internals::Search Internals for searching for modules CPANPLUS::Internals::Source Internals for updating source files CPANPLUS::Internals::Source::Memory In memory implementation CPANPLUS::Internals::Source::SQLite SQLite implementation CPANPLUS::Internals::Utils Convenience functions for CPANPLUS CPANPLUS::Module CPAN module objects for CPANPLUS CPANPLUS::Module::Author CPAN author object for CPANPLUS CPANPLUS::Module::Author::Fake Dummy author object for CPANPLUS CPANPLUS::Module::Checksums Checking the checksum of a distribution CPANPLUS::Module::Fake Fake module object for internal use CPANPLUS::Selfupdate Self-updating for CPANPLUS CPANPLUS::Shell Base class for CPANPLUS shells CPANPLUS::Shell::Classic emulation for CPANPLUS CPANPLUS::Shell::Default The default CPANPLUS shell CPANPLUS::Shell::Default::Plugins::CustomSource Add custom sources to CPANPLUS CPANPLUS::Shell::Default::Plugins::HOWTO Documentation on how to write your own plugins CPANPLUS::Shell::Default::Plugins::Remote Connect to a remote CPANPLUS CPANPLUS::Shell::Default::Plugins::Source Read in CPANPLUS commands Carp Alternative warn and die for modules Class::Struct Declare struct-like datatypes as Perl classes Compress::Raw::Bzip2 Low-Level Interface to bzip2 compression library Compress::Raw::Zlib Low-Level Interface to zlib compression library Compress::Zlib Interface to zlib compression library Config Access Perl configuration information 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::InnerPackage Find all the inner packages of a package 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 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 ESTI 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 'B' and 'Q' header encoding 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_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 ExtUtils::MakeMaker::FAQ Frequently Asked Questions About MakeMaker ExtUtils::MakeMaker::Tutorial Writing a module with MakeMaker ExtUtils::Manifest Utilities to write and check a MANIFEST file ExtUtils::Mkbootstrap Make a bootstrap file for use by DynaLoader ExtUtils::Mksymlists Write linker options files for dynamic extension ExtUtils::Packlist Manage .packlist files ExtUtils::ParseXS Converts Perl XS code into C code ExtUtils::ParseXS::Constants Initialization values for some globals 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::CheckTree Run many filetest checks on a tree 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::Cygwin Methods for Cygwin file specs File::Spec::Epoc Methods for Epoc file specs File::Spec::Functions Portably perform operations on file names File::Spec::Mac File::Spec for Mac OS (Classic) File::Spec::OS2 Methods for OS/2 file specs File::Spec::Unix File::Spec for Unix, base for other File::Spec modules File::Spec::VMS Methods for VMS file specs File::Spec::Win32 Methods for Win32 file specs File::Temp Return name and handle of a temporary file safely File::stat By-name interface to Perl's built-in stat() functions FileCache Keep more files open than the system permits FileHandle Supply object methods for filehandles Filter::Simple Simplified source filtering Filter::Util::Call Perl Source Filter Utility Module FindBin Locate directory of original perl script GDBM_File Perl5 access to the gdbm library. Getopt::Long Extended processing of command line options Getopt::Std Process single-character switches with switch clustering HTTP::Tiny A small, simple, correct HTTP/1.1 client Hash::Util A selection of general-utility hash subroutines Hash::Util::FieldHash Support for Inside-Out Classes I18N::Collate Compare 8-bit scalar data according to the current locale I18N::LangTags Functions for dealing with RFC3066-style language tags I18N::LangTags::Detect Detect the user's language preferences I18N::LangTags::List Tags and names for human languages I18N::Langinfo Query locale information IO Load various IO modules IO::Compress::Base Base Class for IO::Compress modules IO::Compress::Bzip2 Write bzip2 files/buffers IO::Compress::Deflate Write RFC 1950 files/buffers IO::Compress::FAQ Frequently Asked Questions about IO::Compress IO::Compress::Gzip Write RFC 1952 files/buffers IO::Compress::RawDeflate Write RFC 1951 files/buffers IO::Compress::Zip Write zip files/buffers IO::Dir Supply object methods for directory handles IO::File Supply object methods for filehandles IO::Handle Supply object methods for I/O handles IO::Pipe Supply object methods for pipes IO::Poll Object interface to system poll call IO::Seekable Supply seek based methods for I/O objects IO::Select OO interface to the select system call IO::Socket Object interface to socket communications IO::Socket::INET Object interface for AF_INET domain sockets IO::Socket::UNIX Object interface for AF_UNIX domain sockets IO::Uncompress::AnyInflate Uncompress zlib-based (zip, gzip) file/buffer IO::Uncompress::AnyUncompress Uncompress gzip, zip, bzip2 or lzop file/buffer IO::Uncompress::Base Base Class for IO::Uncompress modules IO::Uncompress::Bunzip2 Read bzip2 files/buffers IO::Uncompress::Gunzip Read RFC 1952 files/buffers IO::Uncompress::Inflate Read RFC 1950 files/buffers IO::Uncompress::RawInflate Read RFC 1951 files/buffers IO::Uncompress::Unzip Read zip files/buffers IO::Zlib IO:: style interface to Compress::Zlib IPC::Cmd Finding and running system commands made easy IPC::Msg SysV Msg IPC object class IPC::Open2 Open a process for both reading and writing using open2() IPC::Open3 Open a process for reading, writing, and error handling using open3() IPC::Semaphore SysV Semaphore IPC object class IPC::SharedMem SysV Shared Memory IPC object class IPC::SysV System V IPC constants and system calls 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::Codes A distribution of modules to handle locale codes Locale::Codes::API A description of the callable function in each module Locale::Codes::Changes Details changes to Locale::Codes Locale::Codes::Constants Constants for Locale codes Locale::Codes::Country Standard codes for country identification Locale::Codes::Country_Codes Country codes for the Locale::Codes::Country module Locale::Codes::Country_Retired Retired country codes for the Locale::Codes::Country module Locale::Codes::Currency Standard codes for currency identification Locale::Codes::Currency_Codes Currency codes for the Locale::Codes::Currency module Locale::Codes::Currency_Retired Retired currency codes for the Locale::Codes::Currency module Locale::Codes::LangExt Standard codes for language extension identification Locale::Codes::LangExt_Codes Langext codes for the Locale::Codes::LangExt module Locale::Codes::LangExt_Retired Retired langext codes for the Locale::Codes::LangExt module Locale::Codes::LangFam Standard codes for language extension identification Locale::Codes::LangFam_Codes Langfam codes for the Locale::Codes::LangFam module Locale::Codes::LangFam_Retired Retired langfam codes for the Locale::Codes::LangFam module Locale::Codes::LangVar Standard codes for language variation identification Locale::Codes::LangVar_Codes Langvar codes for the Locale::Codes::LangVar module Locale::Codes::LangVar_Retired Retired langvar codes for the Locale::Codes::LangVar module Locale::Codes::Language Standard codes for language identification Locale::Codes::Language_Codes Language codes for the Locale::Codes::Language module Locale::Codes::Language_Retired Retired language codes for the Locale::Codes::Language module Locale::Codes::Script Standard codes for script identification Locale::Codes::Script_Codes Script codes for the Locale::Codes::Script module Locale::Codes::Script_Retired Retired script codes for the Locale::Codes::Script module Locale::Country Standard codes for country identification Locale::Currency Standard codes for currency identification Locale::Language Standard codes for language identification 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 Locale::Script Standard codes for script identification Log::Message A generic message storing mechanism; Log::Message::Config Configuration options for Log::Message Log::Message::Handlers Message handlers for Log::Message Log::Message::Item Message objects for Log::Message Log::Message::Simple Simplified interface to Log::Message 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/float math package Math::BigInt::Calc Pure Perl module to support Math::BigInt Math::BigInt::CalcEmu Emulate low-level math with BigInt code Math::BigInt::FastCalc Math::BigInt::Calc with some XS for more speed Math::BigRat Arbitrary big rational numbers 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::Build Build and install Perl modules Module::Build::API API Reference for Module Authors Module::Build::Authoring Authoring Module::Build modules Module::Build::Base Default methods for Module::Build Module::Build::Bundling How to bundle Module::Build with a distribution Module::Build::Compat Compatibility with ExtUtils::MakeMaker Module::Build::ConfigData Configuration for Module::Build Module::Build::Cookbook Examples of Module::Build Usage Module::Build::ModuleInfo DEPRECATED Module::Build::Notes Create persistent distribution configuration modules Module::Build::PPMMaker Perl Package Manager file creation Module::Build::Platform::Amiga Builder class for Amiga platforms Module::Build::Platform::Default Stub class for unknown platforms Module::Build::Platform::EBCDIC Builder class for EBCDIC platforms Module::Build::Platform::MPEiX Builder class for MPEiX platforms Module::Build::Platform::MacOS Builder class for MacOS platforms Module::Build::Platform::RiscOS Builder class for RiscOS platforms Module::Build::Platform::Unix Builder class for Unix platforms Module::Build::Platform::VMS Builder class for VMS platforms Module::Build::Platform::VOS Builder class for VOS platforms Module::Build::Platform::Windows Builder class for Windows platforms Module::Build::Platform::aix Builder class for AIX platform Module::Build::Platform::cygwin Builder class for Cygwin platform Module::Build::Platform::darwin Builder class for Mac OS X platform Module::Build::Platform::os2 Builder class for OS/2 platform Module::Build::Version DEPRECATED Module::Build::YAML DEPRECATED Module::CoreList What modules 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 Module::Pluggable Automatically give your module the ability to have plugins Module::Pluggable::Object Automatically give your module the ability to have plugins 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::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 Object::Accessor Interface to create per object accessors Opcode Disable named opcodes when compiling perl code POSIX Perl interface to IEEE Std 1003.1 Package::Constants List all constants declared in a package 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::Find Find POD documents in directory trees Pod::Functions Group Perl's functions a la perlfunc.pod Pod::Html Module to convert pod files to HTML Pod::InputObjects Objects representing POD input paragraphs, commands, etc. Pod::LaTeX Convert Pod data to formatted Latex Pod::Man Convert POD data to formatted *roff input Pod::ParseLink Parse an L<> formatting code in POD text Pod::ParseUtils Helpers for POD parsing and conversion Pod::Parser Base class for creating POD filters and translators 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::PlainText Convert POD data to formatted ASCII text Pod::Select Extract selected sections of POD from input 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::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 ASCII text Pod::Text::Color Convert POD data to formatted color ASCII text Pod::Text::Termcap Convert POD data to ASCII text with format escapes Pod::Usage Print a usage message from embedded pod documentation 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 Symbol Manipulate Perl symbols and their names Sys::Hostname Try every conceivable way to get hostname Sys::Syslog Perl interface to the UNIX syslog(3) calls Sys::Syslog::Win32 Win32 support for Sys::Syslog TAP::Base Base class that provides common functionality to TAP::Parser TAP::Formatter::Base Base class for harness output delegates TAP::Formatter::Color Run Perl test scripts with color TAP::Formatter::Console Harness output delegate for default console output TAP::Formatter::Console::ParallelSession Harness output delegate for parallel console output TAP::Formatter::Console::Session Harness output delegate for default console output TAP::Formatter::File Harness output delegate for file output TAP::Formatter::File::Session Harness output delegate for file output TAP::Formatter::Session Abstract base class for harness output delegate TAP::Harness Run test scripts with statistics TAP::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::Utils Internal TAP::Parser utilities TAP::Parser::YAMLish::Reader Read YAMLish data from iterator TAP::Parser::YAMLish::Writer Write YAMLish data Term::ANSIColor Color screen output using ANSI escape sequences Term::Cap Perl termcap interface Term::Complete Perl word completion module Term::ReadLine Perl interface to various "readline" packages. Term::UI Term::ReadLine UI made easy Term::UI::History History function Test Provides a simple framework for writing test scripts Test::Builder Backend for building test libraries 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::Harness Run Perl standard test scripts with statistics Test::More Yet another framework for writing test scripts Test::Simple Basic utilities for writing tests. Test::Tutorial A tutorial about writing really basic tests 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::Soundex Implementation of the soundex algorithm. Text::Tabs Expand and unexpand tabs per the unix expand(1) and unexpand(1) Text::Wrap Line wrapping to form simple paragraphs Thread Manipulate threads in Perl (for old code only) Thread::Queue Thread-safe queues Thread::Semaphore Thread-safe semaphores Tie::Array Base class for tied arrays Tie::File Access the lines of a disk file via a Perl array Tie::Handle Base class definitions for tied handles Tie::Hash Base class definitions for tied hashes Tie::Hash::NamedCapture Named regexp capture buffers Tie::Memoize Add data to hash when needed Tie::RefHash Use references as hash keys Tie::Scalar Base class definitions for tied scalars Tie::StdHandle Base class definitions for tied handles Tie::SubstrHash Fixed-table-size, fixed-key-length hashing Time::HiRes High resolution alarm, sleep, gettimeofday, interval timers Time::Local Efficiently compute time from local and GMT time Time::Piece Object Oriented time objects Time::Seconds A simple API to convert seconds to other date values Time::gmtime By-name interface to Perl's built-in gmtime() function Time::localtime By-name interface to Perl's built-in localtime() function Time::tm Internal object used by Time::gmtime and Time::localtime UNIVERSAL Base class for ALL classes (blessed references) Unicode::Collate Unicode Collation Algorithm Unicode::Collate::CJK::Big5 Weighting CJK Unified Ideographs Unicode::Collate::CJK::GB2312 Weighting CJK Unified Ideographs Unicode::Collate::CJK::JISX0208 Weighting JIS KANJI for Unicode::Collate Unicode::Collate::CJK::Korean Weighting CJK Unified Ideographs Unicode::Collate::CJK::Pinyin Weighting CJK Unified Ideographs Unicode::Collate::CJK::Stroke Weighting CJK Unified Ideographs Unicode::Collate::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::Stdio Standard I/O functions via VMS extensions Version::Requirements A set of version requirements for a CPAN dist 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 version::Internals Perl extension for Version Objects To find out all modules installed on your system, including those without documentation or outside the standard release, just use the following command (under the default win32 shell, double quotes should be used instead of single quotes). % perl -MFile::Find=find -MFile::Spec::Functions -Tlwe 'find { wanted => sub { print canonpath $_ if /.pmz/ }, no_chdir => 1 }, @INC' (The -T is here to prevent '.' from being listed in @INC.) They should all have their own documentation installed and accessible via your system man(1) command. If you do not have a find program, you can use the Perl find2perl program instead, which generates Perl code as output you can run through perl. If you have a man program but it doesn't find your modules, you'll have to fix your manpath. See perl for details. If you have no system man command, you might try the perldoc program. Note also that the command "perldoc perllocal" gives you a (possibly incomplete) list of the modules that have been further installed on your system. (The perllocal.pod file is updated by the standard MakeMaker install process.) Extension Modules Extension modules are written in C (or a mix of Perl and C). They are usually dynamically loaded into Perl if and when you need them, but may also be linked in statically. Supported extension modules include Socket, Fcntl, and POSIX. Many popular C extension modules do not come bundled (at least, not completely) due to their sizes, volatility, or simply lack of time for adequate testing and configuration across the multitude of platforms on which Perl was beta-tested. You are encouraged to look for them on CPAN (described below), or using web search engines like Alta Vista or Google. 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 Most importantly, CPAN includes around a thousand unbundled modules, some of which require a C compiler to build. Major categories of modules are: o Language Extensions and Documentation Tools o Development Support o Operating System Interfaces o Networking, Device Control (modems) and InterProcess Communication o Data Types and Data Type Utilities o Database Interfaces o User Interfaces o Interfaces to / Emulations of Other Programming Languages o File Names, File Systems and File Locking (see also File Handles) o String Processing, Language Text Processing, Parsing, and Searching o Option, Argument, Parameter, and Configuration File Processing o Internationalization and Locale o Authentication, Security, and Encryption o World Wide Web, HTML, HTTP, CGI, MIME o Server and Daemon Utilities o Archiving and Compression o Images, Pixmap and Bitmap Manipulation, Drawing, and Graphing o Mail and Usenet News o Control Flow Utilities (callbacks and exceptions etc) o File Handle and Input/Output Stream Utilities o Miscellaneous Modules The list of the registered CPAN sites follows. Please note that the sorting order is alphabetical on fields: Continent | |-->Country | |-->[state/province] | |-->ftp | |-->[http] and thus the North American servers happen to be listed between the European and the South American sites. Registered CPAN sites Africa South Africa Asia China Hong Kong India Indonesia Japan Republic of Korea Russia Singapore Taiwan Thailand Turkey Central America Costa Rica Europe Austria Belgium Bosnia and Herzegovina Bulgaria Croatia Czech Republic Denmark Finland France Germany Greece Hungary Iceland Ireland Italy Latvia Lithuania Malta Netherlands Norway Poland Portugal Romania Russia Slovakia Slovenia Spain Sweden Switzerland Ukraine United Kingdom North America Bahamas Canada Mexico United States Alabama Arizona California Florida Idaho Illinois Indiana Massachusetts Michigan Minnesota New Jersey New York North Carolina Oregon Pennsylvania South Carolina Tennessee Texas Utah Virginia Washington Wisconsin Oceania Australia New Zealand South America Argentina Brazil Chile Colombia RSYNC Mirrors rsync:// rsync:// rsync:// rsync:// rsync:// rsync:// rsync:// rsync:// rsync:// rsync:// rsync:// rsync:// rsync:// rsync:// rsync:// rsync:// rsync:// rsync:// For an up-to-date listing of CPAN sites, see or . Modules: Creation, Use, and Abuse (The following section is borrowed directly from Tim Bunce's modules file, available at your nearest CPAN site.) Perl implements a class using a package, but the presence of a package doesn't imply the presence of a class. A package is just a namespace. A class is a package that provides subroutines that can be used as methods. A method is just a subroutine that expects, as its first argument, either the name of a package (for "static" methods), or a reference to something (for "virtual" methods). A module is a file that (by convention) provides a class of the same name (sans the .pm), plus an import method in that class that can be called to fetch exported symbols. This module may implement some of its methods by loading dynamic C or C++ objects, but that should be totally transparent to the user of the module. Likewise, the module might set up an AUTOLOAD function to slurp in subroutine definitions on demand, but this is also transparent. Only the .pm file is required to exist. See perlsub, perlobj, and AutoLoader for details about the AUTOLOAD mechanism. Guidelines for Module Creation o 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. o Try to design the new module to be easy to extend and reuse. Try to "use warnings;" (or "use warnings qw(...);"). Remember that you can add "no warnings qw(...);" to individual blocks of code that need less warnings. Use blessed references. Use the two argument form of bless to bless into the class name given as the first parameter of the constructor, e.g.,: sub new { my $class = shift; return bless {}, $class; } or even this if you'd like it to be used as either a static or a virtual method. sub new { my $self = shift; my $class = ref($self) || $self; return bless {}, $class; } Pass arrays as references so more parameters can be added later (it's also faster). Convert functions into methods where appropriate. Split large methods into smaller more flexible ones. Inherit methods from other modules if appropriate. Avoid class name tests like: "die "Invalid" unless ref $ref eq 'FOO'". Generally you can delete the "eq 'FOO'" part with no harm at all. Let the objects look after themselves! Generally, avoid hard-wired class names as far as possible. Avoid "$r->Class::func()" where using "@ISA=qw(... Class ...)" and "$r->func()" would work. Use autosplit so little used or newly added functions won't be a burden to programs that don't use them. Add test functions to the module after __END__ either using AutoSplit or by saying: eval join('',<main::DATA>) || die $@ unless caller(); Does your module pass the 'empty subclass' test? If you say "@SUBCLASS::ISA = qw(YOURCLASS);" your applications should be able to use SUBCLASS in exactly the same way as YOURCLASS. For example, does your application still work if you change: "$obj = YOURCLASS->new();" into: "$obj = SUBCLASS->new();" ? Avoid keeping any state information in your packages. It makes it difficult for multiple other packages to use yours. Keep state information in objects. Always use -w. Try to "use strict;" (or "use strict qw(...);"). Remember that you can add "no strict qw(...);" to individual blocks of code that need less strictness. Always use -w. Follow the guidelines in perlstyle. Always use -w. o 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. o 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. o 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 in any doubt ask for suggestions in comp.lang.perl.misc. 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. o 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. Comp.lang.perl.misc is read by just about all the people who develop modules and it's the best place to ask. 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! o 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: o A description of the module/package/extension etc. o A copyright notice - see below. o Prerequisites - what else you may need to have. o How to build it - possible changes to Makefile.PL etc. o How to install it. o Recent changes in this release, especially incompatibilities o 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. o 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. o 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 for details. o How to release and distribute a module. It's good idea to post an announcement of the availability of your module (or the module itself if small) to the comp.lang.perl.announce Usenet newsgroup. This will at least ensure very wide once-off distribution. If possible, register the module with CPAN. You should include details of its location in your announcement. Some notes about ftp archives: Please use a long descriptive file name that includes the version number. Most incoming directories will not be readable/listable, i.e., you won't be able to see your file after uploading it. Remember to send your email notification message as soon as possible after uploading else your file may get deleted automatically. Allow time for the file to be processed and/or check the file has been processed before announcing its location. FTP Archives for Perl Modules: Follow the instructions and links on: or upload to one of these sites: and notify <>. 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! Please remember to send me an updated entry for the Module list! o Take care when changing a released module. Always strive to remain compatible with previous released versions. Otherwise try to add a mechanism to revert to the old behavior if people rely on it. Document incompatible changes. Guidelines for Converting Perl 4 Library Scripts into Modules o 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. o 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? o 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. o 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: o Adds the standard Module prologue lines o Converts package specifiers from ' to :: o Converts die(...) to croak(...) o Several other minor changes Being a mechanical process pl2pm is not bullet proof. The converted code will need careful checking, especially any package statements. Don't delete the original .pl file till the new .pm one works! Guidelines for Reusing Application Code o Complete applications rarely belong in the Perl Module Library. o 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. o Break-out the reusable code into one or more separate module files. o Take the opportunity to reconsider and redesign the interfaces. o In some cases the 'application' can then be reduced to a small fragment of code built on top of the reusable modules. In these cases the application could invoked as: % perl -e 'use Module::Name; method(@ARGV)' ... or % perl -mModule::Name ... (in perl5.002 or higher) NOTE
Perl does not enforce private and public parts of its modules as you may have been used to in other languages like C++, Ada, or Modula-17. Perl doesn't have an infatuation with enforced privacy. It would prefer that you stayed out of its living room because you weren't invited, not because it has a shotgun. The module and its user have a contract, part of which is common law, and part of which is "written". Part of the common law contract is that a module doesn't pollute any namespace it wasn't asked to. The written contract for the module (A.K.A. documentation) may make other provisions. But then you know when you "use RedefineTheWorld" that you're redefining the world and willing to take the consequences. perl v5.16.3 2014-06-17 PERLMODLIB(1)
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