1PERLMODLIB(1)          Perl Programmers Reference Guide          PERLMODLIB(1)
2
3
4

NAME

6       perlmodlib - constructing new Perl modules and finding existing ones
7

THE PERL MODULE LIBRARY

9       Many modules are included in the Perl distribution.  These are
10       described below, and all end in .pm.  You may discover compiled library
11       files (usually ending in .so) or small pieces of modules to be
12       autoloaded (ending in .al); these were automatically generated by the
13       installation process.  You may also discover files in the library
14       directory that end in either .pl or .ph.  These are old libraries
15       supplied so that old programs that use them still run.  The .pl files
16       will all eventually be converted into standard modules, and the .ph
17       files made by h2ph will probably end up as extension modules made by
18       h2xs.  (Some .ph values may already be available through the POSIX,
19       Errno, or Fcntl modules.)  The pl2pm file in the distribution may help
20       in your conversion, but it's just a mechanical process and therefore
21       far from bulletproof.
22
23   Pragmatic Modules
24       They work somewhat like compiler directives (pragmata) in that they
25       tend to affect the compilation of your program, and thus will usually
26       work well only when used within a "use", or "no".  Most of these are
27       lexically scoped, so an inner BLOCK may countermand them by saying:
28
29           no integer;
30           no strict 'refs';
31           no warnings;
32
33       which lasts until the end of that BLOCK.
34
35       Some pragmas are lexically scoped--typically those that affect the $^H
36       hints variable.  Others affect the current package instead, like "use
37       vars" and "use subs", which allow you to predeclare a variables or
38       subroutines within a particular file rather than just a block.  Such
39       declarations are effective for the entire file for which they were
40       declared.  You cannot rescind them with "no vars" or "no subs".
41
42       The following pragmas are defined (and have their own documentation).
43
44       attributes  Get/set subroutine or variable attributes
45
46       autodie     Replace functions with ones that succeed or die with
47                   lexical scope
48
49       autodie::exception
50                   Exceptions from autodying functions.
51
52       autodie::exception::system
53                   Exceptions from autodying system().
54
55       autodie::hints
56                   Provide hints about user subroutines to autodie
57
58       autodie::skip
59                   Skip a package when throwing autodie exceptions
60
61       autouse     Postpone load of modules until a function is used
62
63       base        Establish an ISA relationship with base classes at compile
64                   time
65
66       bigfloat    Transparent big floating point number support for Perl
67
68       bigint      Transparent big integer support for Perl
69
70       bignum      Transparent big number support for Perl
71
72       bigrat      Transparent big rational number support for Perl
73
74       blib        Use MakeMaker's uninstalled version of a package
75
76       builtin     Import built-in utility functions
77
78       bytes       Expose the individual bytes of characters
79
80       charnames   Access to Unicode character names and named character
81                   sequences; also define character names
82
83       constant    Declare constants
84
85       deprecate   Perl pragma for deprecating the inclusion of a module in
86                   core
87
88       diagnostics Produce verbose warning diagnostics
89
90       encoding    Allows you to write your script in non-ASCII and non-UTF-8
91
92       encoding::warnings
93                   Warn on implicit encoding conversions
94
95       experimental
96                   Experimental features made easy
97
98       feature     Enable new features
99
100       fields      Compile-time class fields
101
102       filetest    Control the filetest permission operators
103
104       if          "use" a Perl module if a condition holds
105
106       integer     Use integer arithmetic instead of floating point
107
108       less        Request less of something
109
110       lib         Manipulate @INC at compile time
111
112       locale      Use or avoid POSIX locales for built-in operations
113
114       mro         Method Resolution Order
115
116       ok          Alternative to Test::More::use_ok
117
118       open        Set default PerlIO layers for input and output
119
120       ops         Restrict unsafe operations when compiling
121
122       overload    Package for overloading Perl operations
123
124       overloading Lexically control overloading
125
126       parent      Establish an ISA relationship with base classes at compile
127                   time
128
129       re          Alter regular expression behaviour
130
131       sigtrap     Enable simple signal handling
132
133       sort        Control sort() behaviour
134
135       strict      Restrict unsafe constructs
136
137       subs        Predeclare subroutine names
138
139       threads     Perl interpreter-based threads
140
141       threads::shared
142                   Perl extension for sharing data structures between threads
143
144       utf8        Enable/disable UTF-8 (or UTF-EBCDIC) in source code
145
146       vars        Predeclare global variable names
147
148       version     Perl extension for Version Objects
149
150       vmsish      Control VMS-specific language features
151
152       warnings    Control optional warnings
153
154       warnings::register
155                   Warnings import function
156
157   Standard Modules
158       Standard, bundled modules are all expected to behave in a well-defined
159       manner with respect to namespace pollution because they use the
160       Exporter module.  See their own documentation for details.
161
162       It's possible that not all modules listed below are installed on your
163       system. For example, the GDBM_File module will not be installed if you
164       don't have the gdbm library.
165
166       Amiga::ARexx
167                   Perl extension for ARexx support
168
169       Amiga::Exec Perl extension for low level amiga support
170
171       AnyDBM_File Provide framework for multiple DBMs
172
173       App::Cpan   Easily interact with CPAN from the command line
174
175       App::Prove  Implements the "prove" command.
176
177       App::Prove::State
178                   State storage for the "prove" command.
179
180       App::Prove::State::Result
181                   Individual test suite results.
182
183       App::Prove::State::Result::Test
184                   Individual test results.
185
186       Archive::Tar
187                   Module for manipulations of tar archives
188
189       Archive::Tar::File
190                   A subclass for in-memory extracted file from Archive::Tar
191
192       Attribute::Handlers
193                   Simpler definition of attribute handlers
194
195       AutoLoader  Load subroutines only on demand
196
197       AutoSplit   Split a package for autoloading
198
199       B           The Perl Compiler Backend
200
201       B::Concise  Walk Perl syntax tree, printing concise info about ops
202
203       B::Deparse  Perl compiler backend to produce perl code
204
205       B::Op_private
206                   OP op_private flag definitions
207
208       B::Showlex  Show lexical variables used in functions or files
209
210       B::Terse    Walk Perl syntax tree, printing terse info about ops
211
212       B::Xref     Generates cross reference reports for Perl programs
213
214       Benchmark   Benchmark running times of Perl code
215
216       "IO::Socket::IP"
217                   Family-neutral IP socket supporting both IPv4 and IPv6
218
219       "Socket"    Networking constants and support functions
220
221       CORE        Namespace for Perl's core routines
222
223       CPAN        Query, download and build perl modules from CPAN sites
224
225       CPAN::API::HOWTO
226                   A recipe book for programming with CPAN.pm
227
228       CPAN::Debug Internal debugging for CPAN.pm
229
230       CPAN::Distroprefs
231                   Read and match distroprefs
232
233       CPAN::FirstTime
234                   Utility for CPAN::Config file Initialization
235
236       CPAN::HandleConfig
237                   Internal configuration handling for CPAN.pm
238
239       CPAN::Kwalify
240                   Interface between CPAN.pm and Kwalify.pm
241
242       CPAN::Meta  The distribution metadata for a CPAN dist
243
244       CPAN::Meta::Converter
245                   Convert CPAN distribution metadata structures
246
247       CPAN::Meta::Feature
248                   An optional feature provided by a CPAN distribution
249
250       CPAN::Meta::History
251                   History of CPAN Meta Spec changes
252
253       CPAN::Meta::History::Meta_1_0
254                   Version 1.0 metadata specification for META.yml
255
256       CPAN::Meta::History::Meta_1_1
257                   Version 1.1 metadata specification for META.yml
258
259       CPAN::Meta::History::Meta_1_2
260                   Version 1.2 metadata specification for META.yml
261
262       CPAN::Meta::History::Meta_1_3
263                   Version 1.3 metadata specification for META.yml
264
265       CPAN::Meta::History::Meta_1_4
266                   Version 1.4 metadata specification for META.yml
267
268       CPAN::Meta::Merge
269                   Merging CPAN Meta fragments
270
271       CPAN::Meta::Prereqs
272                   A set of distribution prerequisites by phase and type
273
274       CPAN::Meta::Requirements
275                   A set of version requirements for a CPAN dist
276
277       CPAN::Meta::Spec
278                   Specification for CPAN distribution metadata
279
280       CPAN::Meta::Validator
281                   Validate CPAN distribution metadata structures
282
283       CPAN::Meta::YAML
284                   Read and write a subset of YAML for CPAN Meta files
285
286       CPAN::Nox   Wrapper around CPAN.pm without using any XS module
287
288       CPAN::Plugin
289                   Base class for CPAN shell extensions
290
291       CPAN::Plugin::Specfile
292                   Proof of concept implementation of a trivial CPAN::Plugin
293
294       CPAN::Queue Internal queue support for CPAN.pm
295
296       CPAN::Tarzip
297                   Internal handling of tar archives for CPAN.pm
298
299       CPAN::Version
300                   Utility functions to compare CPAN versions
301
302       Carp        Alternative warn and die for modules
303
304       Class::Struct
305                   Declare struct-like datatypes as Perl classes
306
307       Compress::Raw::Bzip2
308                   Low-Level Interface to bzip2 compression library
309
310       Compress::Raw::Zlib
311                   Low-Level Interface to zlib compression library
312
313       Compress::Zlib
314                   Interface to zlib compression library
315
316       Config      Access Perl configuration information
317
318       Config::Extensions
319                   Hash lookup of which core extensions were built.
320
321       Config::Perl::V
322                   Structured data retrieval of perl -V output
323
324       Cwd         Get pathname of current working directory
325
326       DB          Programmatic interface to the Perl debugging API
327
328       DBM_Filter  Filter DBM keys/values
329
330       DBM_Filter::compress
331                   Filter for DBM_Filter
332
333       DBM_Filter::encode
334                   Filter for DBM_Filter
335
336       DBM_Filter::int32
337                   Filter for DBM_Filter
338
339       DBM_Filter::null
340                   Filter for DBM_Filter
341
342       DBM_Filter::utf8
343                   Filter for DBM_Filter
344
345       DB_File     Perl5 access to Berkeley DB version 1.x
346
347       Data::Dumper
348                   Stringified perl data structures, suitable for both
349                   printing and "eval"
350
351       Devel::PPPort
352                   Perl/Pollution/Portability
353
354       Devel::Peek A data debugging tool for the XS programmer
355
356       Devel::SelfStubber
357                   Generate stubs for a SelfLoading module
358
359       Digest      Modules that calculate message digests
360
361       Digest::MD5 Perl interface to the MD5 Algorithm
362
363       Digest::SHA Perl extension for SHA-1/224/256/384/512
364
365       Digest::base
366                   Digest base class
367
368       Digest::file
369                   Calculate digests of files
370
371       DirHandle   (obsolete) supply object methods for directory handles
372
373       Dumpvalue   Provides screen dump of Perl data.
374
375       DynaLoader  Dynamically load C libraries into Perl code
376
377       Encode      Character encodings in Perl
378
379       Encode::Alias
380                   Alias definitions to encodings
381
382       Encode::Byte
383                   Single Byte Encodings
384
385       Encode::CJKConstants
386                   Internally used by Encode::??::ISO_2022_*
387
388       Encode::CN  China-based Chinese Encodings
389
390       Encode::CN::HZ
391                   Internally used by Encode::CN
392
393       Encode::Config
394                   Internally used by Encode
395
396       Encode::EBCDIC
397                   EBCDIC Encodings
398
399       Encode::Encoder
400                   Object Oriented Encoder
401
402       Encode::Encoding
403                   Encode Implementation Base Class
404
405       Encode::GSM0338
406                   ETSI GSM 03.38 Encoding
407
408       Encode::Guess
409                   Guesses encoding from data
410
411       Encode::JP  Japanese Encodings
412
413       Encode::JP::H2Z
414                   Internally used by Encode::JP::2022_JP*
415
416       Encode::JP::JIS7
417                   Internally used by Encode::JP
418
419       Encode::KR  Korean Encodings
420
421       Encode::KR::2022_KR
422                   Internally used by Encode::KR
423
424       Encode::MIME::Header
425                   MIME encoding for an unstructured email header
426
427       Encode::MIME::Name
428                   Internally used by Encode
429
430       Encode::PerlIO
431                   A detailed document on Encode and PerlIO
432
433       Encode::Supported
434                   Encodings supported by Encode
435
436       Encode::Symbol
437                   Symbol Encodings
438
439       Encode::TW  Taiwan-based Chinese Encodings
440
441       Encode::Unicode
442                   Various Unicode Transformation Formats
443
444       Encode::Unicode::UTF7
445                   UTF-7 encoding
446
447       English     Use nice English (or awk) names for ugly punctuation
448                   variables
449
450       Env         Perl module that imports environment variables as scalars
451                   or arrays
452
453       Errno       System errno constants
454
455       Exporter    Implements default import method for modules
456
457       Exporter::Heavy
458                   Exporter guts
459
460       ExtUtils::CBuilder
461                   Compile and link C code for Perl modules
462
463       ExtUtils::CBuilder::Platform::Windows
464                   Builder class for Windows platforms
465
466       ExtUtils::Command
467                   Utilities to replace common UNIX commands in Makefiles etc.
468
469       ExtUtils::Command::MM
470                   Commands for the MM's to use in Makefiles
471
472       ExtUtils::Constant
473                   Generate XS code to import C header constants
474
475       ExtUtils::Constant::Base
476                   Base class for ExtUtils::Constant objects
477
478       ExtUtils::Constant::Utils
479                   Helper functions for ExtUtils::Constant
480
481       ExtUtils::Constant::XS
482                   Generate C code for XS modules' constants.
483
484       ExtUtils::Embed
485                   Utilities for embedding Perl in C/C++ applications
486
487       ExtUtils::Install
488                   Install files from here to there
489
490       ExtUtils::Installed
491                   Inventory management of installed modules
492
493       ExtUtils::Liblist
494                   Determine libraries to use and how to use them
495
496       ExtUtils::MM
497                   OS adjusted ExtUtils::MakeMaker subclass
498
499       ExtUtils::MM::Utils
500                   ExtUtils::MM methods without dependency on
501                   ExtUtils::MakeMaker
502
503       ExtUtils::MM_AIX
504                   AIX specific subclass of ExtUtils::MM_Unix
505
506       ExtUtils::MM_Any
507                   Platform-agnostic MM methods
508
509       ExtUtils::MM_BeOS
510                   Methods to override UN*X behaviour in ExtUtils::MakeMaker
511
512       ExtUtils::MM_Cygwin
513                   Methods to override UN*X behaviour in ExtUtils::MakeMaker
514
515       ExtUtils::MM_DOS
516                   DOS specific subclass of ExtUtils::MM_Unix
517
518       ExtUtils::MM_Darwin
519                   Special behaviors for OS X
520
521       ExtUtils::MM_MacOS
522                   Once produced Makefiles for MacOS Classic
523
524       ExtUtils::MM_NW5
525                   Methods to override UN*X behaviour in ExtUtils::MakeMaker
526
527       ExtUtils::MM_OS2
528                   Methods to override UN*X behaviour in ExtUtils::MakeMaker
529
530       ExtUtils::MM_OS390
531                   OS390 specific subclass of ExtUtils::MM_Unix
532
533       ExtUtils::MM_QNX
534                   QNX specific subclass of ExtUtils::MM_Unix
535
536       ExtUtils::MM_UWIN
537                   U/WIN specific subclass of ExtUtils::MM_Unix
538
539       ExtUtils::MM_Unix
540                   Methods used by ExtUtils::MakeMaker
541
542       ExtUtils::MM_VMS
543                   Methods to override UN*X behaviour in ExtUtils::MakeMaker
544
545       ExtUtils::MM_VOS
546                   VOS specific subclass of ExtUtils::MM_Unix
547
548       ExtUtils::MM_Win32
549                   Methods to override UN*X behaviour in ExtUtils::MakeMaker
550
551       ExtUtils::MM_Win95
552                   Method to customize MakeMaker for Win9X
553
554       ExtUtils::MY
555                   ExtUtils::MakeMaker subclass for customization
556
557       ExtUtils::MakeMaker
558                   Create a module Makefile
559
560       ExtUtils::MakeMaker::Config
561                   Wrapper around Config.pm
562
563       ExtUtils::MakeMaker::FAQ
564                   Frequently Asked Questions About MakeMaker
565
566       ExtUtils::MakeMaker::Locale
567                   Bundled Encode::Locale
568
569       ExtUtils::MakeMaker::Tutorial
570                   Writing a module with MakeMaker
571
572       ExtUtils::Manifest
573                   Utilities to write and check a MANIFEST file
574
575       ExtUtils::Miniperl
576                   Write the C code for miniperlmain.c and perlmain.c
577
578       ExtUtils::Mkbootstrap
579                   Make a bootstrap file for use by DynaLoader
580
581       ExtUtils::Mksymlists
582                   Write linker options files for dynamic extension
583
584       ExtUtils::PL2Bat
585                   Batch file creation to run perl scripts on Windows
586
587       ExtUtils::Packlist
588                   Manage .packlist files
589
590       ExtUtils::ParseXS
591                   Converts Perl XS code into C code
592
593       ExtUtils::ParseXS::Constants
594                   Initialization values for some globals
595
596       ExtUtils::ParseXS::Eval
597                   Clean package to evaluate code in
598
599       ExtUtils::ParseXS::Utilities
600                   Subroutines used with ExtUtils::ParseXS
601
602       ExtUtils::Typemaps
603                   Read/Write/Modify Perl/XS typemap files
604
605       ExtUtils::Typemaps::Cmd
606                   Quick commands for handling typemaps
607
608       ExtUtils::Typemaps::InputMap
609                   Entry in the INPUT section of a typemap
610
611       ExtUtils::Typemaps::OutputMap
612                   Entry in the OUTPUT section of a typemap
613
614       ExtUtils::Typemaps::Type
615                   Entry in the TYPEMAP section of a typemap
616
617       ExtUtils::XSSymSet
618                   Keep sets of symbol names palatable to the VMS linker
619
620       ExtUtils::testlib
621                   Add blib/* directories to @INC
622
623       Fatal       Replace functions with equivalents which succeed or die
624
625       Fcntl       Load the C Fcntl.h defines
626
627       File::Basename
628                   Parse file paths into directory, filename and suffix.
629
630       File::Compare
631                   Compare files or filehandles
632
633       File::Copy  Copy files or filehandles
634
635       File::DosGlob
636                   DOS like globbing and then some
637
638       File::Fetch A generic file fetching mechanism
639
640       File::Find  Traverse a directory tree.
641
642       File::Glob  Perl extension for BSD glob routine
643
644       File::GlobMapper
645                   Extend File Glob to Allow Input and Output Files
646
647       File::Path  Create or remove directory trees
648
649       File::Spec  Portably perform operations on file names
650
651       File::Spec::AmigaOS
652                   File::Spec for AmigaOS
653
654       File::Spec::Cygwin
655                   Methods for Cygwin file specs
656
657       File::Spec::Epoc
658                   Methods for Epoc file specs
659
660       File::Spec::Functions
661                   Portably perform operations on file names
662
663       File::Spec::Mac
664                   File::Spec for Mac OS (Classic)
665
666       File::Spec::OS2
667                   Methods for OS/2 file specs
668
669       File::Spec::Unix
670                   File::Spec for Unix, base for other File::Spec modules
671
672       File::Spec::VMS
673                   Methods for VMS file specs
674
675       File::Spec::Win32
676                   Methods for Win32 file specs
677
678       File::Temp  Return name and handle of a temporary file safely
679
680       File::stat  By-name interface to Perl's built-in stat() functions
681
682       FileCache   Keep more files open than the system permits
683
684       FileHandle  Supply object methods for filehandles
685
686       Filter::Simple
687                   Simplified source filtering
688
689       Filter::Util::Call
690                   Perl Source Filter Utility Module
691
692       FindBin     Locate directory of original perl script
693
694       GDBM_File   Perl5 access to the gdbm library.
695
696       Getopt::Long
697                   Extended processing of command line options
698
699       Getopt::Std Process single-character switches with switch clustering
700
701       HTTP::Tiny  A small, simple, correct HTTP/1.1 client
702
703       Hash::Util  A selection of general-utility hash subroutines
704
705       Hash::Util::FieldHash
706                   Support for Inside-Out Classes
707
708       I18N::Collate
709                   Compare 8-bit scalar data according to the current locale
710
711       I18N::LangTags
712                   Functions for dealing with RFC3066-style language tags
713
714       I18N::LangTags::Detect
715                   Detect the user's language preferences
716
717       I18N::LangTags::List
718                   Tags and names for human languages
719
720       I18N::Langinfo
721                   Query locale information
722
723       IO          Load various IO modules
724
725       IO::Compress::Base
726                   Base Class for IO::Compress modules
727
728       IO::Compress::Bzip2
729                   Write bzip2 files/buffers
730
731       IO::Compress::Deflate
732                   Write RFC 1950 files/buffers
733
734       IO::Compress::FAQ
735                   Frequently Asked Questions about IO::Compress
736
737       IO::Compress::Gzip
738                   Write RFC 1952 files/buffers
739
740       IO::Compress::RawDeflate
741                   Write RFC 1951 files/buffers
742
743       IO::Compress::Zip
744                   Write zip files/buffers
745
746       IO::Dir     Supply object methods for directory handles
747
748       IO::File    Supply object methods for filehandles
749
750       IO::Handle  Supply object methods for I/O handles
751
752       IO::Pipe    Supply object methods for pipes
753
754       IO::Poll    Object interface to system poll call
755
756       IO::Seekable
757                   Supply seek based methods for I/O objects
758
759       IO::Select  OO interface to the select system call
760
761       IO::Socket  Object interface to socket communications
762
763       IO::Socket::INET
764                   Object interface for AF_INET domain sockets
765
766       IO::Socket::UNIX
767                   Object interface for AF_UNIX domain sockets
768
769       IO::Uncompress::AnyInflate
770                   Uncompress zlib-based (zip, gzip) file/buffer
771
772       IO::Uncompress::AnyUncompress
773                   Uncompress gzip, zip, bzip2, zstd, xz, lzma, lzip, lzf or
774                   lzop file/buffer
775
776       IO::Uncompress::Base
777                   Base Class for IO::Uncompress modules
778
779       IO::Uncompress::Bunzip2
780                   Read bzip2 files/buffers
781
782       IO::Uncompress::Gunzip
783                   Read RFC 1952 files/buffers
784
785       IO::Uncompress::Inflate
786                   Read RFC 1950 files/buffers
787
788       IO::Uncompress::RawInflate
789                   Read RFC 1951 files/buffers
790
791       IO::Uncompress::Unzip
792                   Read zip files/buffers
793
794       IO::Zlib    IO:: style interface to Compress::Zlib
795
796       IPC::Cmd    Finding and running system commands made easy
797
798       IPC::Msg    SysV Msg IPC object class
799
800       IPC::Open2  Open a process for both reading and writing using open2()
801
802       IPC::Open3  Open a process for reading, writing, and error handling
803                   using open3()
804
805       IPC::Semaphore
806                   SysV Semaphore IPC object class
807
808       IPC::SharedMem
809                   SysV Shared Memory IPC object class
810
811       IPC::SysV   System V IPC constants and system calls
812
813       Internals   Reserved special namespace for internals related functions
814
815       JSON::PP    JSON::XS compatible pure-Perl module.
816
817       JSON::PP::Boolean
818                   Dummy module providing JSON::PP::Boolean
819
820       List::Util  A selection of general-utility list subroutines
821
822       List::Util::XS
823                   Indicate if List::Util was compiled with a C compiler
824
825       Locale::Maketext
826                   Framework for localization
827
828       Locale::Maketext::Cookbook
829                   Recipes for using Locale::Maketext
830
831       Locale::Maketext::Guts
832                   Deprecated module to load Locale::Maketext utf8 code
833
834       Locale::Maketext::GutsLoader
835                   Deprecated module to load Locale::Maketext utf8 code
836
837       Locale::Maketext::Simple
838                   Simple interface to Locale::Maketext::Lexicon
839
840       Locale::Maketext::TPJ13
841                   Article about software localization
842
843       MIME::Base64
844                   Encoding and decoding of base64 strings
845
846       MIME::QuotedPrint
847                   Encoding and decoding of quoted-printable strings
848
849       Math::BigFloat
850                   Arbitrary size floating point math package
851
852       Math::BigInt
853                   Arbitrary size integer math package
854
855       Math::BigInt::Calc
856                   Pure Perl module to support Math::BigInt
857
858       Math::BigInt::FastCalc
859                   Math::BigInt::Calc with some XS for more speed
860
861       Math::BigInt::Lib
862                   Virtual parent class for Math::BigInt libraries
863
864       Math::BigRat
865                   Arbitrary size rational number math package
866
867       Math::Complex
868                   Complex numbers and associated mathematical functions
869
870       Math::Trig  Trigonometric functions
871
872       Memoize     Make functions faster by trading space for time
873
874       Memoize::AnyDBM_File
875                   Glue to provide EXISTS for AnyDBM_File for Storable use
876
877       Memoize::Expire
878                   Plug-in module for automatic expiration of memoized values
879
880       Memoize::ExpireFile
881                   Test for Memoize expiration semantics
882
883       Memoize::ExpireTest
884                   Test for Memoize expiration semantics
885
886       Memoize::NDBM_File
887                   Glue to provide EXISTS for NDBM_File for Storable use
888
889       Memoize::SDBM_File
890                   Glue to provide EXISTS for SDBM_File for Storable use
891
892       Memoize::Storable
893                   Store Memoized data in Storable database
894
895       Module::CoreList
896                   What modules shipped with versions of perl
897
898       Module::CoreList::Utils
899                   What utilities shipped with versions of perl
900
901       Module::Load
902                   Runtime require of both modules and files
903
904       Module::Load::Conditional
905                   Looking up module information / loading at runtime
906
907       Module::Loaded
908                   Mark modules as loaded or unloaded
909
910       Module::Metadata
911                   Gather package and POD information from perl module files
912
913       NDBM_File   Tied access to ndbm files
914
915       NEXT        Provide a pseudo-class NEXT (et al) that allows method
916                   redispatch
917
918       Net::Cmd    Network Command class (as used by FTP, SMTP etc)
919
920       Net::Config Local configuration data for libnet
921
922       Net::Domain Attempt to evaluate the current host's internet name and
923                   domain
924
925       Net::FTP    FTP Client class
926
927       Net::FTP::dataconn
928                   FTP Client data connection class
929
930       Net::NNTP   NNTP Client class
931
932       Net::Netrc  OO interface to users netrc file
933
934       Net::POP3   Post Office Protocol 3 Client class (RFC1939)
935
936       Net::Ping   Check a remote host for reachability
937
938       Net::SMTP   Simple Mail Transfer Protocol Client
939
940       Net::Time   Time and daytime network client interface
941
942       Net::hostent
943                   By-name interface to Perl's built-in gethost*() functions
944
945       Net::libnetFAQ
946                   Libnet Frequently Asked Questions
947
948       Net::netent By-name interface to Perl's built-in getnet*() functions
949
950       Net::protoent
951                   By-name interface to Perl's built-in getproto*() functions
952
953       Net::servent
954                   By-name interface to Perl's built-in getserv*() functions
955
956       O           Generic interface to Perl Compiler backends
957
958       ODBM_File   Tied access to odbm files
959
960       Opcode      Disable named opcodes when compiling perl code
961
962       POSIX       Perl interface to IEEE Std 1003.1
963
964       Params::Check
965                   A generic input parsing/checking mechanism.
966
967       Parse::CPAN::Meta
968                   Parse META.yml and META.json CPAN metadata files
969
970       Perl::OSType
971                   Map Perl operating system names to generic types
972
973       PerlIO      On demand loader for PerlIO layers and root of PerlIO::*
974                   name space
975
976       PerlIO::encoding
977                   Encoding layer
978
979       PerlIO::mmap
980                   Memory mapped IO
981
982       PerlIO::scalar
983                   In-memory IO, scalar IO
984
985       PerlIO::via Helper class for PerlIO layers implemented in perl
986
987       PerlIO::via::QuotedPrint
988                   PerlIO layer for quoted-printable strings
989
990       Pod::Checker
991                   Check pod documents for syntax errors
992
993       Pod::Escapes
994                   For resolving Pod E<...> sequences
995
996       Pod::Functions
997                   Group Perl's functions a la perlfunc.pod
998
999       Pod::Html   Module to convert pod files to HTML
1000
1001       Pod::Html::Util
1002                   Helper functions for Pod-Html
1003
1004       Pod::Man    Convert POD data to formatted *roff input
1005
1006       Pod::ParseLink
1007                   Parse an L<> formatting code in POD text
1008
1009       Pod::Perldoc
1010                   Look up Perl documentation in Pod format.
1011
1012       Pod::Perldoc::BaseTo
1013                   Base for Pod::Perldoc formatters
1014
1015       Pod::Perldoc::GetOptsOO
1016                   Customized option parser for Pod::Perldoc
1017
1018       Pod::Perldoc::ToANSI
1019                   Render Pod with ANSI color escapes
1020
1021       Pod::Perldoc::ToChecker
1022                   Let Perldoc check Pod for errors
1023
1024       Pod::Perldoc::ToMan
1025                   Let Perldoc render Pod as man pages
1026
1027       Pod::Perldoc::ToNroff
1028                   Let Perldoc convert Pod to nroff
1029
1030       Pod::Perldoc::ToPod
1031                   Let Perldoc render Pod as ... Pod!
1032
1033       Pod::Perldoc::ToRtf
1034                   Let Perldoc render Pod as RTF
1035
1036       Pod::Perldoc::ToTerm
1037                   Render Pod with terminal escapes
1038
1039       Pod::Perldoc::ToText
1040                   Let Perldoc render Pod as plaintext
1041
1042       Pod::Perldoc::ToTk
1043                   Let Perldoc use Tk::Pod to render Pod
1044
1045       Pod::Perldoc::ToXml
1046                   Let Perldoc render Pod as XML
1047
1048       Pod::Simple Framework for parsing Pod
1049
1050       Pod::Simple::Checker
1051                   Check the Pod syntax of a document
1052
1053       Pod::Simple::Debug
1054                   Put Pod::Simple into trace/debug mode
1055
1056       Pod::Simple::DumpAsText
1057                   Dump Pod-parsing events as text
1058
1059       Pod::Simple::DumpAsXML
1060                   Turn Pod into XML
1061
1062       Pod::Simple::HTML
1063                   Convert Pod to HTML
1064
1065       Pod::Simple::HTMLBatch
1066                   Convert several Pod files to several HTML files
1067
1068       Pod::Simple::JustPod
1069                   Just the Pod, the whole Pod, and nothing but the Pod
1070
1071       Pod::Simple::LinkSection
1072                   Represent "section" attributes of L codes
1073
1074       Pod::Simple::Methody
1075                   Turn Pod::Simple events into method calls
1076
1077       Pod::Simple::PullParser
1078                   A pull-parser interface to parsing Pod
1079
1080       Pod::Simple::PullParserEndToken
1081                   End-tokens from Pod::Simple::PullParser
1082
1083       Pod::Simple::PullParserStartToken
1084                   Start-tokens from Pod::Simple::PullParser
1085
1086       Pod::Simple::PullParserTextToken
1087                   Text-tokens from Pod::Simple::PullParser
1088
1089       Pod::Simple::PullParserToken
1090                   Tokens from Pod::Simple::PullParser
1091
1092       Pod::Simple::RTF
1093                   Format Pod as RTF
1094
1095       Pod::Simple::Search
1096                   Find POD documents in directory trees
1097
1098       Pod::Simple::SimpleTree
1099                   Parse Pod into a simple parse tree
1100
1101       Pod::Simple::Subclassing
1102                   Write a formatter as a Pod::Simple subclass
1103
1104       Pod::Simple::Text
1105                   Format Pod as plaintext
1106
1107       Pod::Simple::TextContent
1108                   Get the text content of Pod
1109
1110       Pod::Simple::XHTML
1111                   Format Pod as validating XHTML
1112
1113       Pod::Simple::XMLOutStream
1114                   Turn Pod into XML
1115
1116       Pod::Text   Convert POD data to formatted text
1117
1118       Pod::Text::Color
1119                   Convert POD data to formatted color ASCII text
1120
1121       Pod::Text::Overstrike
1122                   Convert POD data to formatted overstrike text
1123
1124       Pod::Text::Termcap
1125                   Convert POD data to ASCII text with format escapes
1126
1127       Pod::Usage  Extracts POD documentation and shows usage information
1128
1129       SDBM_File   Tied access to sdbm files
1130
1131       Safe        Compile and execute code in restricted compartments
1132
1133       Scalar::Util
1134                   A selection of general-utility scalar subroutines
1135
1136       Search::Dict
1137                   Look - search for key in dictionary file
1138
1139       SelectSaver Save and restore selected file handle
1140
1141       SelfLoader  Load functions only on demand
1142
1143       Storable    Persistence for Perl data structures
1144
1145       Sub::Util   A selection of utility subroutines for subs and CODE
1146                   references
1147
1148       Symbol      Manipulate Perl symbols and their names
1149
1150       Sys::Hostname
1151                   Try every conceivable way to get hostname
1152
1153       Sys::Syslog Perl interface to the UNIX syslog(3) calls
1154
1155       Sys::Syslog::Win32
1156                   Win32 support for Sys::Syslog
1157
1158       TAP::Base   Base class that provides common functionality to
1159                   TAP::Parser
1160
1161       TAP::Formatter::Base
1162                   Base class for harness output delegates
1163
1164       TAP::Formatter::Color
1165                   Run Perl test scripts with color
1166
1167       TAP::Formatter::Console
1168                   Harness output delegate for default console output
1169
1170       TAP::Formatter::Console::ParallelSession
1171                   Harness output delegate for parallel console output
1172
1173       TAP::Formatter::Console::Session
1174                   Harness output delegate for default console output
1175
1176       TAP::Formatter::File
1177                   Harness output delegate for file output
1178
1179       TAP::Formatter::File::Session
1180                   Harness output delegate for file output
1181
1182       TAP::Formatter::Session
1183                   Abstract base class for harness output delegate
1184
1185       TAP::Harness
1186                   Run test scripts with statistics
1187
1188       TAP::Harness::Env
1189                   Parsing harness related environmental variables where
1190                   appropriate
1191
1192       TAP::Object Base class that provides common functionality to all
1193                   "TAP::*" modules
1194
1195       TAP::Parser Parse TAP output
1196
1197       TAP::Parser::Aggregator
1198                   Aggregate TAP::Parser results
1199
1200       TAP::Parser::Grammar
1201                   A grammar for the Test Anything Protocol.
1202
1203       TAP::Parser::Iterator
1204                   Base class for TAP source iterators
1205
1206       TAP::Parser::Iterator::Array
1207                   Iterator for array-based TAP sources
1208
1209       TAP::Parser::Iterator::Process
1210                   Iterator for process-based TAP sources
1211
1212       TAP::Parser::Iterator::Stream
1213                   Iterator for filehandle-based TAP sources
1214
1215       TAP::Parser::IteratorFactory
1216                   Figures out which SourceHandler objects to use for a given
1217                   Source
1218
1219       TAP::Parser::Multiplexer
1220                   Multiplex multiple TAP::Parsers
1221
1222       TAP::Parser::Result
1223                   Base class for TAP::Parser output objects
1224
1225       TAP::Parser::Result::Bailout
1226                   Bailout result token.
1227
1228       TAP::Parser::Result::Comment
1229                   Comment result token.
1230
1231       TAP::Parser::Result::Plan
1232                   Plan result token.
1233
1234       TAP::Parser::Result::Pragma
1235                   TAP pragma token.
1236
1237       TAP::Parser::Result::Test
1238                   Test result token.
1239
1240       TAP::Parser::Result::Unknown
1241                   Unknown result token.
1242
1243       TAP::Parser::Result::Version
1244                   TAP syntax version token.
1245
1246       TAP::Parser::Result::YAML
1247                   YAML result token.
1248
1249       TAP::Parser::ResultFactory
1250                   Factory for creating TAP::Parser output objects
1251
1252       TAP::Parser::Scheduler
1253                   Schedule tests during parallel testing
1254
1255       TAP::Parser::Scheduler::Job
1256                   A single testing job.
1257
1258       TAP::Parser::Scheduler::Spinner
1259                   A no-op job.
1260
1261       TAP::Parser::Source
1262                   A TAP source & meta data about it
1263
1264       TAP::Parser::SourceHandler
1265                   Base class for different TAP source handlers
1266
1267       TAP::Parser::SourceHandler::Executable
1268                   Stream output from an executable TAP source
1269
1270       TAP::Parser::SourceHandler::File
1271                   Stream TAP from a text file.
1272
1273       TAP::Parser::SourceHandler::Handle
1274                   Stream TAP from an IO::Handle or a GLOB.
1275
1276       TAP::Parser::SourceHandler::Perl
1277                   Stream TAP from a Perl executable
1278
1279       TAP::Parser::SourceHandler::RawTAP
1280                   Stream output from raw TAP in a scalar/array ref.
1281
1282       TAP::Parser::YAMLish::Reader
1283                   Read YAMLish data from iterator
1284
1285       TAP::Parser::YAMLish::Writer
1286                   Write YAMLish data
1287
1288       Term::ANSIColor
1289                   Color screen output using ANSI escape sequences
1290
1291       Term::Cap   Perl termcap interface
1292
1293       Term::Complete
1294                   Perl word completion module
1295
1296       Term::ReadLine
1297                   Perl interface to various "readline" packages.
1298
1299       Test        Provides a simple framework for writing test scripts
1300
1301       Test2       Framework for writing test tools that all work together.
1302
1303       Test2::API  Primary interface for writing Test2 based testing tools.
1304
1305       Test2::API::Breakage
1306                   What breaks at what version
1307
1308       Test2::API::Context
1309                   Object to represent a testing context.
1310
1311       Test2::API::Instance
1312                   Object used by Test2::API under the hood
1313
1314       Test2::API::InterceptResult
1315                   Representation of a list of events.
1316
1317       Test2::API::InterceptResult::Event
1318                   Representation of an event for use in
1319
1320       Test2::API::InterceptResult::Hub
1321                   Hub used by InterceptResult.
1322
1323       Test2::API::InterceptResult::Squasher
1324                   Encapsulation of the algorithm that
1325
1326       Test2::API::Stack
1327                   Object to manage a stack of Test2::Hub
1328
1329       Test2::Event
1330                   Base class for events
1331
1332       Test2::Event::Bail
1333                   Bailout!
1334
1335       Test2::Event::Diag
1336                   Diag event type
1337
1338       Test2::Event::Encoding
1339                   Set the encoding for the output stream
1340
1341       Test2::Event::Exception
1342                   Exception event
1343
1344       Test2::Event::Fail
1345                   Event for a simple failed assertion
1346
1347       Test2::Event::Generic
1348                   Generic event type.
1349
1350       Test2::Event::Note
1351                   Note event type
1352
1353       Test2::Event::Ok
1354                   Ok event type
1355
1356       Test2::Event::Pass
1357                   Event for a simple passing assertion
1358
1359       Test2::Event::Plan
1360                   The event of a plan
1361
1362       Test2::Event::Skip
1363                   Skip event type
1364
1365       Test2::Event::Subtest
1366                   Event for subtest types
1367
1368       Test2::Event::TAP::Version
1369                   Event for TAP version.
1370
1371       Test2::Event::V2
1372                   Second generation event.
1373
1374       Test2::Event::Waiting
1375                   Tell all procs/threads it is time to be done
1376
1377       Test2::EventFacet
1378                   Base class for all event facets.
1379
1380       Test2::EventFacet::About
1381                   Facet with event details.
1382
1383       Test2::EventFacet::Amnesty
1384                   Facet for assertion amnesty.
1385
1386       Test2::EventFacet::Assert
1387                   Facet representing an assertion.
1388
1389       Test2::EventFacet::Control
1390                   Facet for hub actions and behaviors.
1391
1392       Test2::EventFacet::Error
1393                   Facet for errors that need to be shown.
1394
1395       Test2::EventFacet::Hub
1396                   Facet for the hubs an event passes through.
1397
1398       Test2::EventFacet::Info
1399                   Facet for information a developer might care about.
1400
1401       Test2::EventFacet::Info::Table
1402                   Intermediary representation of a table.
1403
1404       Test2::EventFacet::Meta
1405                   Facet for meta-data
1406
1407       Test2::EventFacet::Parent
1408                   Facet for events contains other events
1409
1410       Test2::EventFacet::Plan
1411                   Facet for setting the plan
1412
1413       Test2::EventFacet::Render
1414                   Facet that dictates how to render an event.
1415
1416       Test2::EventFacet::Trace
1417                   Debug information for events
1418
1419       Test2::Formatter
1420                   Namespace for formatters.
1421
1422       Test2::Formatter::TAP
1423                   Standard TAP formatter
1424
1425       Test2::Hub  The conduit through which all events flow.
1426
1427       Test2::Hub::Interceptor
1428                   Hub used by interceptor to grab results.
1429
1430       Test2::Hub::Interceptor::Terminator
1431                   Exception class used by
1432
1433       Test2::Hub::Subtest
1434                   Hub used by subtests
1435
1436       Test2::IPC  Turn on IPC for threading or forking support.
1437
1438       Test2::IPC::Driver
1439                   Base class for Test2 IPC drivers.
1440
1441       Test2::IPC::Driver::Files
1442                   Temp dir + Files concurrency model.
1443
1444       Test2::Tools::Tiny
1445                   Tiny set of tools for unfortunate souls who cannot use
1446
1447       Test2::Transition
1448                   Transition notes when upgrading to Test2
1449
1450       Test2::Util Tools used by Test2 and friends.
1451
1452       Test2::Util::ExternalMeta
1453                   Allow third party tools to safely attach meta-data
1454
1455       Test2::Util::Facets2Legacy
1456                   Convert facet data to the legacy event API.
1457
1458       Test2::Util::HashBase
1459                   Build hash based classes.
1460
1461       Test2::Util::Trace
1462                   Legacy wrapper fro Test2::EventFacet::Trace.
1463
1464       Test::Builder
1465                   Backend for building test libraries
1466
1467       Test::Builder::Formatter
1468                   Test::Builder subclass of Test2::Formatter::TAP
1469
1470       Test::Builder::IO::Scalar
1471                   A copy of IO::Scalar for Test::Builder
1472
1473       Test::Builder::Module
1474                   Base class for test modules
1475
1476       Test::Builder::Tester
1477                   Test testsuites that have been built with
1478
1479       Test::Builder::Tester::Color
1480                   Turn on colour in Test::Builder::Tester
1481
1482       Test::Builder::TodoDiag
1483                   Test::Builder subclass of Test2::Event::Diag
1484
1485       Test::Harness
1486                   Run Perl standard test scripts with statistics
1487
1488       Test::Harness::Beyond
1489                   Beyond make test
1490
1491       Test::More  Yet another framework for writing test scripts
1492
1493       Test::Simple
1494                   Basic utilities for writing tests.
1495
1496       Test::Tester
1497                   Ease testing test modules built with Test::Builder
1498
1499       Test::Tester::Capture
1500                   Help testing test modules built with Test::Builder
1501
1502       Test::Tester::CaptureRunner
1503                   Help testing test modules built with Test::Builder
1504
1505       Test::Tutorial
1506                   A tutorial about writing really basic tests
1507
1508       Test::use::ok
1509                   Alternative to Test::More::use_ok
1510
1511       Text::Abbrev
1512                   Abbrev - create an abbreviation table from a list
1513
1514       Text::Balanced
1515                   Extract delimited text sequences from strings.
1516
1517       Text::ParseWords
1518                   Parse text into an array of tokens or array of arrays
1519
1520       Text::Tabs  Expand and unexpand tabs like unix expand(1) and
1521                   unexpand(1)
1522
1523       Text::Wrap  Line wrapping to form simple paragraphs
1524
1525       Thread      Manipulate threads in Perl (for old code only)
1526
1527       Thread::Queue
1528                   Thread-safe queues
1529
1530       Thread::Semaphore
1531                   Thread-safe semaphores
1532
1533       Tie::Array  Base class for tied arrays
1534
1535       Tie::File   Access the lines of a disk file via a Perl array
1536
1537       Tie::Handle Base class definitions for tied handles
1538
1539       Tie::Hash   Base class definitions for tied hashes
1540
1541       Tie::Hash::NamedCapture
1542                   Named regexp capture buffers
1543
1544       Tie::Memoize
1545                   Add data to hash when needed
1546
1547       Tie::RefHash
1548                   Use references as hash keys
1549
1550       Tie::Scalar Base class definitions for tied scalars
1551
1552       Tie::StdHandle
1553                   Base class definitions for tied handles
1554
1555       Tie::SubstrHash
1556                   Fixed-table-size, fixed-key-length hashing
1557
1558       Time::HiRes High resolution alarm, sleep, gettimeofday, interval timers
1559
1560       Time::Local Efficiently compute time from local and GMT time
1561
1562       Time::Piece Object Oriented time objects
1563
1564       Time::Seconds
1565                   A simple API to convert seconds to other date values
1566
1567       Time::gmtime
1568                   By-name interface to Perl's built-in gmtime() function
1569
1570       Time::localtime
1571                   By-name interface to Perl's built-in localtime() function
1572
1573       Time::tm    Internal object used by Time::gmtime and Time::localtime
1574
1575       UNIVERSAL   Base class for ALL classes (blessed references)
1576
1577       Unicode::Collate
1578                   Unicode Collation Algorithm
1579
1580       Unicode::Collate::CJK::Big5
1581                   Weighting CJK Unified Ideographs
1582
1583       Unicode::Collate::CJK::GB2312
1584                   Weighting CJK Unified Ideographs
1585
1586       Unicode::Collate::CJK::JISX0208
1587                   Weighting JIS KANJI for Unicode::Collate
1588
1589       Unicode::Collate::CJK::Korean
1590                   Weighting CJK Unified Ideographs
1591
1592       Unicode::Collate::CJK::Pinyin
1593                   Weighting CJK Unified Ideographs
1594
1595       Unicode::Collate::CJK::Stroke
1596                   Weighting CJK Unified Ideographs
1597
1598       Unicode::Collate::CJK::Zhuyin
1599                   Weighting CJK Unified Ideographs
1600
1601       Unicode::Collate::Locale
1602                   Linguistic tailoring for DUCET via Unicode::Collate
1603
1604       Unicode::Normalize
1605                   Unicode Normalization Forms
1606
1607       Unicode::UCD
1608                   Unicode character database
1609
1610       User::grent By-name interface to Perl's built-in getgr*() functions
1611
1612       User::pwent By-name interface to Perl's built-in getpw*() functions
1613
1614       VMS::DCLsym Perl extension to manipulate DCL symbols
1615
1616       VMS::Filespec
1617                   Convert between VMS and Unix file specification syntax
1618
1619       VMS::Stdio  Standard I/O functions via VMS extensions
1620
1621       Win32       Interfaces to some Win32 API Functions
1622
1623       Win32API::File
1624                   Low-level access to Win32 system API calls for files/dirs.
1625
1626       Win32CORE   Win32 CORE function stubs
1627
1628       XS::APItest Test the perl C API
1629
1630       XS::Typemap Module to test the XS typemaps distributed with perl
1631
1632       XSLoader    Dynamically load C libraries into Perl code
1633
1634       autodie::Scope::Guard
1635                   Wrapper class for calling subs at end of scope
1636
1637       autodie::Scope::GuardStack
1638                   Hook stack for managing scopes via %^H
1639
1640       autodie::Util
1641                   Internal Utility subroutines for autodie and Fatal
1642
1643       version::Internals
1644                   Perl extension for Version Objects
1645
1646       To find out all modules installed on your system, including those
1647       without documentation or outside the standard release, just use the
1648       following command (under the default win32 shell, double quotes should
1649       be used instead of single quotes).
1650
1651           % perl -MFile::Find=find -MFile::Spec::Functions -Tlwe \
1652             'find { wanted => sub { print canonpath $_ if /\.pm\z/ },
1653             no_chdir => 1 }, @INC'
1654
1655       (The -T is here to prevent @INC from being populated by "PERL5LIB",
1656       "PERLLIB", and "PERL_USE_UNSAFE_INC".)  They should all have their own
1657       documentation installed and accessible via your system man(1) command.
1658       If you do not have a find program, you can use the Perl find2perl
1659       program instead, which generates Perl code as output you can run
1660       through perl.  If you have a man program but it doesn't find your
1661       modules, you'll have to fix your manpath.  See perl for details.  If
1662       you have no system man command, you might try the perldoc program.
1663
1664       Note also that the command "perldoc perllocal" gives you a (possibly
1665       incomplete) list of the modules that have been further installed on
1666       your system. (The perllocal.pod file is updated by the standard
1667       MakeMaker install process.)
1668
1669   Extension Modules
1670       Extension modules are written in C (or a mix of Perl and C).  They are
1671       usually dynamically loaded into Perl if and when you need them, but may
1672       also be linked in statically.  Supported extension modules include
1673       Socket, Fcntl, and POSIX.
1674
1675       Many popular C extension modules do not come bundled (at least, not
1676       completely) due to their sizes, volatility, or simply lack of time for
1677       adequate testing and configuration across the multitude of platforms on
1678       which Perl was beta-tested.  You are encouraged to look for them on
1679       CPAN (described below), or using web search engines like Google or
1680       DuckDuckGo.
1681

CPAN

1683       CPAN stands for Comprehensive Perl Archive Network; it's a globally
1684       replicated trove of Perl materials, including documentation, style
1685       guides, tricks and traps, alternate ports to non-Unix systems and
1686       occasional binary distributions for these.   Search engines for CPAN
1687       can be found at https://www.cpan.org/
1688
1689       Most importantly, CPAN includes around a thousand unbundled modules,
1690       some of which require a C compiler to build.  Major categories of
1691       modules are:
1692
1693       •   Language Extensions and Documentation Tools
1694
1695       •   Development Support
1696
1697       •   Operating System Interfaces
1698
1699       •   Networking, Device Control (modems) and InterProcess Communication
1700
1701       •   Data Types and Data Type Utilities
1702
1703       •   Database Interfaces
1704
1705       •   User Interfaces
1706
1707       •   Interfaces to / Emulations of Other Programming Languages
1708
1709       •   File Names, File Systems and File Locking (see also File Handles)
1710
1711       •   String Processing, Language Text Processing, Parsing, and Searching
1712
1713       •   Option, Argument, Parameter, and Configuration File Processing
1714
1715       •   Internationalization and Locale
1716
1717       •   Authentication, Security, and Encryption
1718
1719       •   World Wide Web, HTML, HTTP, CGI, MIME
1720
1721       •   Server and Daemon Utilities
1722
1723       •   Archiving and Compression
1724
1725       •   Images, Pixmap and Bitmap Manipulation, Drawing, and Graphing
1726
1727       •   Mail and Usenet News
1728
1729       •   Control Flow Utilities (callbacks and exceptions etc)
1730
1731       •   File Handle and Input/Output Stream Utilities
1732
1733       •   Miscellaneous Modules
1734
1735       You can find the CPAN online at <https://www.cpan.org/>
1736

Modules: Creation, Use, and Abuse

1738       (The following section is borrowed directly from Tim Bunce's modules
1739       file, available at your nearest CPAN site.)
1740
1741       Perl implements a class using a package, but the presence of a package
1742       doesn't imply the presence of a class.  A package is just a namespace.
1743       A class is a package that provides subroutines that can be used as
1744       methods.  A method is just a subroutine that expects, as its first
1745       argument, either the name of a package (for "static" methods), or a
1746       reference to something (for "virtual" methods).
1747
1748       A module is a file that (by convention) provides a class of the same
1749       name (sans the .pm), plus an import method in that class that can be
1750       called to fetch exported symbols.  This module may implement some of
1751       its methods by loading dynamic C or C++ objects, but that should be
1752       totally transparent to the user of the module.  Likewise, the module
1753       might set up an AUTOLOAD function to slurp in subroutine definitions on
1754       demand, but this is also transparent.  Only the .pm file is required to
1755       exist.  See perlsub, perlobj, and AutoLoader for details about the
1756       AUTOLOAD mechanism.
1757
1758   Guidelines for Module Creation
1759       •   Do similar modules already exist in some form?
1760
1761           If so, please try to reuse the existing modules either in whole or
1762           by inheriting useful features into a new class.  If this is not
1763           practical try to get together with the module authors to work on
1764           extending or enhancing the functionality of the existing modules.
1765           A perfect example is the plethora of packages in perl4 for dealing
1766           with command line options.
1767
1768           If you are writing a module to expand an already existing set of
1769           modules, please coordinate with the author of the package.  It
1770           helps if you follow the same naming scheme and module interaction
1771           scheme as the original author.
1772
1773       •   Try to design the new module to be easy to extend and reuse.
1774
1775           Try to "use warnings;" (or "use warnings qw(...);").  Remember that
1776           you can add "no warnings qw(...);" to individual blocks of code
1777           that need less warnings.
1778
1779           Use blessed references.  Use the two argument form of bless to
1780           bless into the class name given as the first parameter of the
1781           constructor, e.g.,:
1782
1783            sub new {
1784                my $class = shift;
1785                return bless {}, $class;
1786            }
1787
1788           or even this if you'd like it to be used as either a static or a
1789           virtual method.
1790
1791            sub new {
1792                my $self  = shift;
1793                my $class = ref($self) || $self;
1794                return bless {}, $class;
1795            }
1796
1797           Pass arrays as references so more parameters can be added later
1798           (it's also faster).  Convert functions into methods where
1799           appropriate.  Split large methods into smaller more flexible ones.
1800           Inherit methods from other modules if appropriate.
1801
1802           Avoid class name tests like: "die "Invalid" unless ref $ref eq
1803           'FOO'".  Generally you can delete the "eq 'FOO'" part with no harm
1804           at all.  Let the objects look after themselves! Generally, avoid
1805           hard-wired class names as far as possible.
1806
1807           Avoid "$r->Class::func()" where using "@ISA=qw(... Class ...)" and
1808           "$r->func()" would work.
1809
1810           Use autosplit so little used or newly added functions won't be a
1811           burden to programs that don't use them. Add test functions to the
1812           module after __END__ either using AutoSplit or by saying:
1813
1814            eval join('',<main::DATA>) || die $@ unless caller();
1815
1816           Does your module pass the 'empty subclass' test? If you say
1817           "@SUBCLASS::ISA = qw(YOURCLASS);" your applications should be able
1818           to use SUBCLASS in exactly the same way as YOURCLASS.  For example,
1819           does your application still work if you change:  "$obj =
1820           YOURCLASS->new();" into: "$obj = SUBCLASS->new();" ?
1821
1822           Avoid keeping any state information in your packages. It makes it
1823           difficult for multiple other packages to use yours. Keep state
1824           information in objects.
1825
1826           Always use -w.
1827
1828           Try to "use strict;" (or "use strict qw(...);").  Remember that you
1829           can add "no strict qw(...);" to individual blocks of code that need
1830           less strictness.
1831
1832           Always use -w.
1833
1834           Follow the guidelines in perlstyle.
1835
1836           Always use -w.
1837
1838       •   Some simple style guidelines
1839
1840           The perlstyle manual supplied with Perl has many helpful points.
1841
1842           Coding style is a matter of personal taste. Many people evolve
1843           their style over several years as they learn what helps them write
1844           and maintain good code.  Here's one set of assorted suggestions
1845           that seem to be widely used by experienced developers:
1846
1847           Use underscores to separate words.  It is generally easier to read
1848           $var_names_like_this than $VarNamesLikeThis, especially for non-
1849           native speakers of English. It's also a simple rule that works
1850           consistently with VAR_NAMES_LIKE_THIS.
1851
1852           Package/Module names are an exception to this rule. Perl informally
1853           reserves lowercase module names for 'pragma' modules like integer
1854           and strict. Other modules normally begin with a capital letter and
1855           use mixed case with no underscores (need to be short and portable).
1856
1857           You may find it helpful to use letter case to indicate the scope or
1858           nature of a variable. For example:
1859
1860            $ALL_CAPS_HERE   constants only (beware clashes with Perl vars)
1861            $Some_Caps_Here  package-wide global/static
1862            $no_caps_here    function scope my() or local() variables
1863
1864           Function and method names seem to work best as all lowercase.
1865           e.g., "$obj->as_string()".
1866
1867           You can use a leading underscore to indicate that a variable or
1868           function should not be used outside the package that defined it.
1869
1870       •   Select what to export.
1871
1872           Do NOT export method names!
1873
1874           Do NOT export anything else by default without a good reason!
1875
1876           Exports pollute the namespace of the module user.  If you must
1877           export try to use @EXPORT_OK in preference to @EXPORT and avoid
1878           short or common names to reduce the risk of name clashes.
1879
1880           Generally anything not exported is still accessible from outside
1881           the module using the ModuleName::item_name (or
1882           "$blessed_ref->method") syntax.  By convention you can use a
1883           leading underscore on names to indicate informally that they are
1884           'internal' and not for public use.
1885
1886           (It is actually possible to get private functions by saying: "my
1887           $subref = sub { ... };  &$subref;".  But there's no way to call
1888           that directly as a method, because a method must have a name in the
1889           symbol table.)
1890
1891           As a general rule, if the module is trying to be object oriented
1892           then export nothing. If it's just a collection of functions then
1893           @EXPORT_OK anything but use @EXPORT with caution.
1894
1895       •   Select a name for the module.
1896
1897           This name should be as descriptive, accurate, and complete as
1898           possible.  Avoid any risk of ambiguity. Always try to use two or
1899           more whole words.  Generally the name should reflect what is
1900           special about what the module does rather than how it does it.
1901           Please use nested module names to group informally or categorize a
1902           module.  There should be a very good reason for a module not to
1903           have a nested name.  Module names should begin with a capital
1904           letter.
1905
1906           Having 57 modules all called Sort will not make life easy for
1907           anyone (though having 23 called Sort::Quick is only marginally
1908           better :-).  Imagine someone trying to install your module
1909           alongside many others.
1910
1911           If you are developing a suite of related modules/classes it's good
1912           practice to use nested classes with a common prefix as this will
1913           avoid namespace clashes. For example: Xyz::Control, Xyz::View,
1914           Xyz::Model etc. Use the modules in this list as a naming guide.
1915
1916           If adding a new module to a set, follow the original author's
1917           standards for naming modules and the interface to methods in those
1918           modules.
1919
1920           If developing modules for private internal or project specific use,
1921           that will never be released to the public, then you should ensure
1922           that their names will not clash with any future public module. You
1923           can do this either by using the reserved Local::* category or by
1924           using a category name that includes an underscore like Foo_Corp::*.
1925
1926           To be portable each component of a module name should be limited to
1927           11 characters. If it might be used on MS-DOS then try to ensure
1928           each is unique in the first 8 characters. Nested modules make this
1929           easier.
1930
1931           For additional guidance on the naming of modules, please consult:
1932
1933               https://pause.perl.org/pause/query?ACTION=pause_namingmodules
1934
1935           or send mail to the <module-authors@perl.org> mailing list.
1936
1937       •   Have you got it right?
1938
1939           How do you know that you've made the right decisions? Have you
1940           picked an interface design that will cause problems later? Have you
1941           picked the most appropriate name? Do you have any questions?
1942
1943           The best way to know for sure, and pick up many helpful
1944           suggestions, is to ask someone who knows. The
1945           <module-authors@perl.org> mailing list is useful for this purpose;
1946           it's also accessible via news interface as perl.module-authors at
1947           nntp.perl.org.
1948
1949           All you need to do is post a short summary of the module, its
1950           purpose and interfaces. A few lines on each of the main methods is
1951           probably enough. (If you post the whole module it might be ignored
1952           by busy people - generally the very people you want to read it!)
1953
1954           Don't worry about posting if you can't say when the module will be
1955           ready - just say so in the message. It might be worth inviting
1956           others to help you, they may be able to complete it for you!
1957
1958       •   README and other Additional Files.
1959
1960           It's well known that software developers usually fully document the
1961           software they write. If, however, the world is in urgent need of
1962           your software and there is not enough time to write the full
1963           documentation please at least provide a README file containing:
1964
1965           •         A description of the module/package/extension etc.
1966
1967           •         A copyright notice - see below.
1968
1969           •         Prerequisites - what else you may need to have.
1970
1971           •         How to build it - possible changes to Makefile.PL etc.
1972
1973           •         How to install it.
1974
1975           •         Recent changes in this release, especially
1976                     incompatibilities
1977
1978           •         Changes / enhancements you plan to make in the future.
1979
1980           If the README file seems to be getting too large you may wish to
1981           split out some of the sections into separate files: INSTALL,
1982           Copying, ToDo etc.
1983
1984           •   Adding a Copyright Notice.
1985
1986               How you choose to license your work is a personal decision.
1987               The general mechanism is to assert your Copyright and then make
1988               a declaration of how others may copy/use/modify your work.
1989
1990               Perl, for example, is supplied with two types of licence: The
1991               GNU GPL and The Artistic Licence (see the files README,
1992               Copying, and Artistic, or perlgpl and perlartistic).  Larry has
1993               good reasons for NOT just using the GNU GPL.
1994
1995               My personal recommendation, out of respect for Larry, Perl, and
1996               the Perl community at large is to state something simply like:
1997
1998                Copyright (c) 1995 Your Name. All rights reserved.
1999                This program is free software; you can redistribute it and/or
2000                modify it under the same terms as Perl itself.
2001
2002               This statement should at least appear in the README file. You
2003               may also wish to include it in a Copying file and your source
2004               files.  Remember to include the other words in addition to the
2005               Copyright.
2006
2007           •   Give the module a version/issue/release number.
2008
2009               To be fully compatible with the Exporter and MakeMaker modules
2010               you should store your module's version number in a non-my
2011               package variable called $VERSION.  This should be a positive
2012               floating point number with at least two digits after the
2013               decimal (i.e., hundredths, e.g, "$VERSION = "0.01"").  Don't
2014               use a "1.3.2" style version.  See Exporter for details.
2015
2016               It may be handy to add a function or method to retrieve the
2017               number.  Use the number in announcements and archive file names
2018               when releasing the module (ModuleName-1.02.tar.Z).  See perldoc
2019               ExtUtils::MakeMaker.pm for details.
2020
2021           •   How to release and distribute a module.
2022
2023               If possible, register the module with CPAN. Follow the
2024               instructions and links on:
2025
2026                  https://www.cpan.org/modules/04pause.html
2027
2028               and upload to:
2029
2030                  https://pause.perl.org/
2031
2032               and notify <modules@perl.org>. This will allow anyone to
2033               install your module using the "cpan" tool distributed with
2034               Perl.
2035
2036               By using the WWW interface you can ask the Upload Server to
2037               mirror your modules from your ftp or WWW site into your own
2038               directory on CPAN!
2039
2040           •   Take care when changing a released module.
2041
2042               Always strive to remain compatible with previous released
2043               versions.  Otherwise try to add a mechanism to revert to the
2044               old behavior if people rely on it.  Document incompatible
2045               changes.
2046
2047   Guidelines for Converting Perl 4 Library Scripts into Modules
2048       •   There is no requirement to convert anything.
2049
2050           If it ain't broke, don't fix it! Perl 4 library scripts should
2051           continue to work with no problems. You may need to make some minor
2052           changes (like escaping non-array @'s in double quoted strings) but
2053           there is no need to convert a .pl file into a Module for just that.
2054
2055       •   Consider the implications.
2056
2057           All Perl applications that make use of the script will need to be
2058           changed (slightly) if the script is converted into a module.  Is it
2059           worth it unless you plan to make other changes at the same time?
2060
2061       •   Make the most of the opportunity.
2062
2063           If you are going to convert the script to a module you can use the
2064           opportunity to redesign the interface.  The guidelines for module
2065           creation above include many of the issues you should consider.
2066
2067       •   The pl2pm utility will get you started.
2068
2069           This utility will read *.pl files (given as parameters) and write
2070           corresponding *.pm files. The pl2pm utilities does the following:
2071
2072           •         Adds the standard Module prologue lines
2073
2074           •         Converts package specifiers from ' to ::
2075
2076           •         Converts die(...) to croak(...)
2077
2078           •         Several other minor changes
2079
2080           Being a mechanical process pl2pm is not bullet proof. The converted
2081           code will need careful checking, especially any package statements.
2082           Don't delete the original .pl file till the new .pm one works!
2083
2084   Guidelines for Reusing Application Code
2085       •   Complete applications rarely belong in the Perl Module Library.
2086
2087       •   Many applications contain some Perl code that could be reused.
2088
2089           Help save the world! Share your code in a form that makes it easy
2090           to reuse.
2091
2092       •   Break-out the reusable code into one or more separate module files.
2093
2094       •   Take the opportunity to reconsider and redesign the interfaces.
2095
2096       •   In some cases the 'application' can then be reduced to a small
2097
2098           fragment of code built on top of the reusable modules. In these
2099           cases the application could invoked as:
2100
2101                % perl -e 'use Module::Name; method(@ARGV)' ...
2102           or
2103                % perl -mModule::Name ...    (in perl5.002 or higher)
2104

NOTE

2106       Perl does not enforce private and public parts of its modules as you
2107       may have been used to in other languages like C++, Ada, or Modula-17.
2108       Perl doesn't have an infatuation with enforced privacy.  It would
2109       prefer that you stayed out of its living room because you weren't
2110       invited, not because it has a shotgun.
2111
2112       The module and its user have a contract, part of which is common law,
2113       and part of which is "written".  Part of the common law contract is
2114       that a module doesn't pollute any namespace it wasn't asked to.  The
2115       written contract for the module (A.K.A. documentation) may make other
2116       provisions.  But then you know when you "use RedefineTheWorld" that
2117       you're redefining the world and willing to take the consequences.
2118
2119
2120
2121perl v5.36.3                      2023-11-30                     PERLMODLIB(1)
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