PERLMODLIB(1) Perl Programmers Reference Guide PERLMODLIB(1)NAMEperlmodlib - constructing new Perl modules and finding
existing ones
DESCRIPTIONTHE PERL MODULE LIBRARY
Many modules are included the Perl distribution. These
are described below, and all end in .pm. You may discover
compiled library file (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 sup
plied 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 pro
cess 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 cur
rent 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 doc
umentation).
attributes Get/set subroutine or variable attributes
attrs Set/get attributes of a subroutine (depre
cated)
autouse Postpone load of modules until a function is
used
base Establish IS-A relationship with base class at
compile time
blib Use MakeMaker's uninstalled version of a pack
age
bytes Force byte semantics rather than character
semantics
charnames Define character names for "\N{named}" string
literal escape.
constant Declare constants
diagnostics Perl compiler pragma to force verbose warning
diagnostics
fields Compile-time class fields
filetest Control the filetest permission operators
integer Use integer arithmetic instead of floating
point
less Request less of something from the compiler
lib Manipulate @INC at compile time
locale Use and avoid POSIX locales for built-in oper
ations
open Set default disciplines for input and output
ops Restrict unsafe operations when compiling
overload Package for overloading perl operations
re Alter regular expression behaviour
sigtrap Enable simple signal handling
strict Restrict unsafe constructs
subs Predeclare sub names
utf8 Enable/disable UTF-8 in source code
vars Predeclare global variable names (obsolete)
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 docu
mentation for details.
AnyDBM_File Provide framework for multiple DBMs
AutoLoader Load subroutines only on demand
AutoSplit Split a package for autoloading
B The Perl Compiler
B::Asmdata Autogenerated data about Perl ops, used to
generate bytecode
B::Assembler
Assemble Perl bytecode
B::Bblock Walk basic blocks
B::Bytecode Perl compiler's bytecode backend
B::C Perl compiler's C backend
B::CC Perl compiler's optimized C translation back
end
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::Disassembler
Disassemble Perl bytecode
B::Lint Perl lint
B::Showlex Show lexical variables used in functions or
files
B::Stackobj Helper module for CC backend
B::Stash Show what stashes are loaded
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
ByteLoader Load byte compiled perl code
CGI Simple Common Gateway Interface Class
CGI::Apache Backward compatibility module for CGI.pm
CGI::Carp CGI routines for writing to the HTTPD (or
other) error log
CGI::Cookie Interface to Netscape 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
CPAN Query, download and build perl modules from
CPAN sites
CPAN::FirstTime
Utility for CPAN::Config file Initialization
CPAN::Nox Wrapper around CPAN.pm without using any XS
module
Carp Warn of errors (from perspective of caller)
Carp::Heavy Carp guts
Class::Struct
Declare struct-like datatypes as Perl classes
Cwd Get pathname of current working directory
DB Programmatic interface to the Perl debugging
API (draft, subject to
DB_File Perl5 access to Berkeley DB version 1.x
Devel::SelfStubber
Generate stubs for a SelfLoading module
DirHandle Supply object methods for directory handles
Dumpvalue Provides screen dump of Perl data.
English Use nice English (or awk) names for ugly punc
tuation variables
Env Perl module that imports environment variables
as scalars or arrays
Exporter Implements default import method for modules
Exporter::Heavy
Exporter guts
ExtUtils::Command
Utilities to replace common UNIX commands in
Makefiles etc.
ExtUtils::Embed
Utilities for embedding Perl in C/C++ applica
tions
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_Cygwin
Methods to override UN*X behaviour in ExtU
tils::MakeMaker
ExtUtils::MM_OS2
Methods to override UN*X behaviour in ExtU
tils::MakeMaker
ExtUtils::MM_Unix
Methods used by ExtUtils::MakeMaker
ExtUtils::MM_VMS
Methods to override UN*X behaviour in ExtU
tils::MakeMaker
ExtUtils::MM_Win32
Methods to override UN*X behaviour in ExtU
tils::MakeMaker
ExtUtils::MakeMaker
Create an extension Makefile
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 exten
sion
ExtUtils::Packlist
Manage .packlist files
ExtUtils::testlib
Add blib/* directories to @INC
Fatal Replace functions with equivalents which suc
ceed or die
Fcntl Load the C Fcntl.h defines
File::Basename
Split a pathname into pieces
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::Find Traverse a file tree
File::Path Create or remove directory trees
File::Spec Portably perform operations on file names
File::Spec::Epoc
Methods for Epoc file specs
File::Spec::Functions
Portably perform operations on file names
File::Spec::Mac
File::Spec for MacOS
File::Spec::OS2
Methods for OS/2 file specs
File::Spec::Unix
Methods used by File::Spec
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
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
I18N::Collate
Compare 8-bit scalar data according to the
current locale
IO Load various IO modules
IPC::Open2 Open a process for both reading and writing
IPC::Open3 Open a process for reading, writing, and error
handling
Math::BigFloat
Arbitrary length float math package
Math::BigInt
Arbitrary size integer math package
Math::Complex
Complex numbers and associated mathematical
functions
Math::Trig Trigonometric functions
Net::Ping Check a remote host for reachability
Net::hostent
By-name interface to Perl's built-in geth
ost*() functions
Net::netent By-name interface to Perl's built-in getnet*()
functions
Net::protoent
By-name interface to Perl's built-in get
proto*() functions
Net::servent
By-name interface to Perl's built-in get
serv*() functions
O Generic interface to Perl Compiler backends
Opcode Disable named opcodes when compiling perl code
POSIX Perl interface to IEEE Std 1003.1
Pod::Checker
Check pod documents for syntax errors
Pod::Find Find POD documents in directory trees
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::ParseUtils
Helpers for POD parsing and conversion
Pod::Parser Base class for creating POD filters and trans
lators
Pod::Plainer
Perl extension for converting Pod to old style
Pod.
Pod::Select Extract selected sections of POD from input
Pod::Text Convert POD data to formatted ASCII text
Pod::Text::Color
Convert POD data to formatted color ASCII text
Pod::Text::Overstrike
Convert POD data to formatted overstrike text
Pod::Text::Termcap
Convert POD data to ASCII text with format
escapes
Pod::Usage Print a usage message from embedded pod docu
mentation
SDBM_File Tied access to sdbm files
Safe Compile and execute code in restricted com
partments
Search::Dict
Search for key in dictionary file
SelectSaver Save and restore selected file handle
SelfLoader Load functions only on demand
Shell Run shell commands transparently within perl
Socket Load the C socket.h defines and structure
manipulators
Symbol Manipulate Perl symbols and their names
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.
If
Test Provides a simple framework for writing test
scripts
Test::Harness
Run perl standard test scripts with statistics
Text::Abbrev
Create an abbreviation table from a list
Text::ParseWords
Parse text into an array of tokens or array of
arrays
Text::Soundex
Implementation of the Soundex Algorithm as
Described by Knuth
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 (EXPERIMENTAL, sub
ject to change)
Thread::Queue
Thread-safe queues
Thread::Semaphore
Thread-safe semaphores
Thread::Signal
Start a thread which runs signal handlers
reliably
Thread::Specific
Thread-specific keys
Tie::Array Base class for tied arrays
Tie::Handle Base class definitions for tied handles
Tie::Hash Base class definitions for tied hashes
Tie::RefHash
Use references as hash keys
Tie::Scalar Base class definitions for tied scalars
Tie::SubstrHash
Fixed-table-size, fixed-key-length hashing
Time::Local Efficiently compute time from local and GMT
time
Time::gmtime
By-name interface to Perl's built-in gmtime()
function
Time::localtime
By-name interface to Perl's built-in local_
time() function
Time::tm Internal object used by Time::gmtime and
Time::localtime
UNIVERSAL Base class for ALL classes (blessed refer
ences)
User::grent By-name interface to Perl's built-in getgr*()
functions
User::pwent By-name interface to Perl's built-in getpw*()
functions
Win32 Interfaces to some Win32 API Functions
To find out all modules installed on your system, includ
ing those without documentation or outside the standard
release, just do this:
% find `perl -e 'print "@INC"'` -name '*.pm' -print
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 pro
gram 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 man
path. See the perl manpage for details. If you have no
system man command, you might try the perldoc program.
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 be linked in stati
cally. 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 Deja News.
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 distribu
tions for these. Search engines for CPAN can be found at
http://cpan.perl.com/ and at http://theory.uwin
nipeg.ca/mod_perl/cpan-search.pl .
Most importantly, CPAN includes around a thousand unbun
dled modules, some of which require a C compiler to build.
Major categories of modules are:
Language Extensions and Documentation Tools
Development Support
Operating System Interfaces
Networking, Device Control (modems) and InterProcess
Communication
Data Types and Data Type Utilities
Database Interfaces
User Interfaces
Interfaces to / Emulations of Other Programming Lan
guages
File Names, File Systems and File Locking (see also
File Handles)
String Processing, Language Text Processing, Parsing,
and Searching
Option, Argument, Parameter, and Configuration File
Processing
Internationalization and Locale
Authentication, Security, and Encryption
World Wide Web, HTML, HTTP, CGI, MIME
Server and Daemon Utilities
Archiving and Compression
Images, Pixmap and Bitmap Manipulation, Drawing, and
Graphing
Mail and Usenet News
Control Flow Utilities (callbacks and exceptions etc)
File Handle and Input/Output Stream Utilities
Miscellaneous Modules
Registered CPAN sites as of this writing include the fol
lowing. You should try to choose one close to you:
Africa
South Africa
ftp://ftp.is.co.za/programming/perl/CPAN/
ftp://ftp.saix.net/pub/CPAN/
ftp://ftpza.co.za/pub/mirrors/cpan/
ftp://ftp.sun.ac.za/CPAN/
Asia
China
ftp://freesoft.cei.gov.cn/pub/languages/perl/CPAN/
http://www2.linuxforum.net/mirror/CPAN/
http://cpan.shellhung.org/
ftp://ftp.shellhung.org/pub/CPAN
Hong Kong
http://CPAN.pacific.net.hk/
ftp://ftp.pacific.net.hk/pub/mirror/CPAN/
Indonesia
http://piksi.itb.ac.id/CPAN/
ftp://mirrors.piksi.itb.ac.id/CPAN/
http://CPAN.mweb.co.id/
ftp://ftp.mweb.co.id/pub/languages/perl/CPAN/
Israel
http://www.iglu.org.il:/pub/CPAN/
ftp://ftp.iglu.org.il/pub/CPAN/
http://bioinfo.weizmann.ac.il/pub/software/perl/CPAN/
ftp://bioinfo.weizmann.ac.il/pub/software/perl/CPAN/
Japan
ftp://ftp.u-aizu.ac.jp/pub/lang/perl/CPAN/
ftp://ftp.kddlabs.co.jp/CPAN/
http://mirror.nucba.ac.jp/mirror/Perl/
ftp://mirror.nucba.ac.jp/mirror/Perl/
ftp://ftp.meisei-u.ac.jp/pub/CPAN/
ftp://ftp.jaist.ac.jp/pub/lang/perl/CPAN/
ftp://ftp.dti.ad.jp/pub/lang/CPAN/
ftp://ftp.ring.gr.jp/pub/lang/perl/CPAN/
Saudi Arabia
ftp://ftp.isu.net.sa/pub/CPAN/
Singapore
http://cpan.hjc.edu.sg
http://ftp.nus.edu.sg/unix/perl/CPAN/
ftp://ftp.nus.edu.sg/pub/unix/perl/CPAN/
South Korea
http://CPAN.bora.net/
ftp://ftp.bora.net/pub/CPAN/
http://ftp.kornet.net/CPAN/
ftp://ftp.kornet.net/pub/CPAN/
ftp://ftp.nuri.net/pub/CPAN/
Taiwan
ftp://coda.nctu.edu.tw/UNIX/perl/CPAN
ftp://ftp.ee.ncku.edu.tw/pub/perl/CPAN/
ftp://ftp1.sinica.edu.tw/pub1/perl/CPAN/
Thailand
http://download.nectec.or.th/CPAN/
ftp://ftp.nectec.or.th/pub/languages/CPAN/
ftp://ftp.cs.riubon.ac.th/pub/mirrors/CPAN/
Central America
Costa Rica
ftp://ftp.linux.co.cr/mirrors/CPAN/
http://ftp.ucr.ac.cr/Unix/CPAN/
ftp://ftp.ucr.ac.cr/pub/Unix/CPAN/
Europe
Austria
ftp://ftp.tuwien.ac.at/pub/languages/perl/CPAN/
Belgium
http://ftp.easynet.be/CPAN/
ftp://ftp.easynet.be/CPAN/
ftp://ftp.kulnet.kuleuven.ac.be/pub/mirror/CPAN/
Bulgaria
ftp://ftp.ntrl.net/pub/mirrors/CPAN/
Croatia
ftp://ftp.linux.hr/pub/CPAN/
Czech Republic
http://www.fi.muni.cz/pub/perl/
ftp://ftp.fi.muni.cz/pub/perl/
ftp://sunsite.mff.cuni.cz/MIRRORS/ftp.funet.fi/pub/languages/perl/CPAN/
Denmark
ftp://sunsite.auc.dk/pub/languages/perl/CPAN/
http://www.cpan.dk/CPAN/
ftp://www.cpan.dk/ftp.cpan.org/CPAN/
England
http://www.mirror.ac.uk/sites/ftp.funet.fi/pub/languages/perl/CPAN
ftp://ftp.mirror.ac.uk/sites/ftp.funet.fi/pub/languages/perl/CPAN/
ftp://ftp.demon.co.uk/pub/mirrors/perl/CPAN/
ftp://ftp.flirble.org/pub/languages/perl/CPAN/
ftp://ftp.plig.org/pub/CPAN/
ftp://sunsite.doc.ic.ac.uk/packages/CPAN/
http://mirror.uklinux.net/CPAN/
ftp://mirror.uklinux.net/pub/CPAN/
ftp://usit.shef.ac.uk/pub/packages/CPAN/
Estonia
ftp://ftp.ut.ee/pub/languages/perl/CPAN/
Finland
ftp://ftp.funet.fi/pub/languages/perl/CPAN/
France
ftp://cpan.ftp.worldonline.fr/pub/CPAN/
ftp://ftp.club-internet.fr/pub/perl/CPAN/
ftp://ftp.lip6.fr/pub/perl/CPAN/
ftp://ftp.oleane.net/pub/mirrors/CPAN/
ftp://ftp.pasteur.fr/pub/computing/CPAN/
ftp://cpan.cict.fr/pub/CPAN/
ftp://ftp.uvsq.fr/pub/perl/CPAN/
Germany
ftp://ftp.rz.ruhr-uni-bochum.de/pub/CPAN/
ftp://ftp.freenet.de/pub/ftp.cpan.org/pub/CPAN/
ftp://ftp.uni-erlangen.de/pub/source/CPAN/
ftp://ftp-stud.fht-esslingen.de/pub/Mirrors/CPAN
ftp://ftp.gigabell.net/pub/CPAN/
http://ftp.gwdg.de/pub/languages/perl/CPAN/
ftp://ftp.gwdg.de/pub/languages/perl/CPAN/
ftp://ftp.uni-hamburg.de/pub/soft/lang/perl/CPAN/
ftp://ftp.leo.org/pub/comp/general/programming/languages/script/perl/CPAN/
ftp://ftp.mpi-sb.mpg.de/pub/perl/CPAN/
ftp://ftp.gmd.de/mirrors/CPAN/
Greece
ftp://ftp.forthnet.gr/pub/languages/perl/CPAN
ftp://ftp.ntua.gr/pub/lang/perl/
Hungary
http://cpan.artifact.hu/
ftp://cpan.artifact.hu/CPAN/
ftp://ftp.kfki.hu/pub/packages/perl/CPAN/
Iceland
http://cpan.gm.is/
ftp://ftp.gm.is/pub/CPAN/
Ireland
http://cpan.indigo.ie/
ftp://cpan.indigo.ie/pub/CPAN/
http://sunsite.compapp.dcu.ie/pub/perl/
ftp://sunsite.compapp.dcu.ie/pub/perl/
Italy
http://cpan.nettuno.it/
http://gusp.dyndns.org/CPAN/
ftp://gusp.dyndns.org/pub/CPAN
http://softcity.iol.it/cpan
ftp://softcity.iol.it/pub/cpan
ftp://ftp.unina.it/pub/Other/CPAN/
ftp://ftp.unipi.it/pub/mirror/perl/CPAN/
ftp://cis.uniRoma2.it/CPAN/
ftp://ftp.edisontel.it/pub/CPAN_Mirror/
ftp://ftp.flashnet.it/pub/CPAN/
Latvia
http://kvin.lv/pub/CPAN/
Netherlands
ftp://download.xs4all.nl/pub/mirror/CPAN/
ftp://ftp.nl.uu.net/pub/CPAN/
ftp://ftp.nluug.nl/pub/languages/perl/CPAN/
ftp://ftp.cpan.nl/pub/CPAN/
http://www.cs.uu.nl/mirror/CPAN/
ftp://ftp.cs.uu.nl/mirror/CPAN/
Norway
ftp://sunsite.uio.no/pub/languages/perl/CPAN/
ftp://ftp.uit.no/pub/languages/perl/cpan/
Poland
ftp://ftp.pk.edu.pl/pub/lang/perl/CPAN/
ftp://ftp.mega.net.pl/pub/mirrors/ftp.perl.com/
ftp://ftp.man.torun.pl/pub/doc/CPAN/
ftp://sunsite.icm.edu.pl/pub/CPAN/
Portugal
ftp://ftp.ua.pt/pub/CPAN/
ftp://perl.di.uminho.pt/pub/CPAN/
ftp://ftp.ist.utl.pt/pub/CPAN/
ftp://ftp.netc.pt/pub/CPAN/
Romania
ftp://archive.logicnet.ro/mirrors/ftp.cpan.org/CPAN/
ftp://ftp.kappa.ro/pub/mirrors/ftp.perl.org/pub/CPAN/
ftp://ftp.dntis.ro/pub/cpan/
ftp://ftp.opsynet.com/cpan/
ftp://ftp.dnttm.ro/pub/CPAN/
ftp://ftp.timisoara.roedu.net/mirrors/CPAN/
Russia
ftp://ftp.chg.ru/pub/lang/perl/CPAN/
http://cpan.rinet.ru/
ftp://cpan.rinet.ru/pub/mirror/CPAN/
ftp://ftp.aha.ru/pub/CPAN/
ftp://ftp.sai.msu.su/pub/lang/perl/CPAN/
Slovakia
ftp://ftp.entry.sk/pub/languages/perl/CPAN/
Slovenia
ftp://ftp.arnes.si/software/perl/CPAN/
Spain
ftp://ftp.rediris.es/mirror/CPAN/
ftp://ftp.etse.urv.es/pub/perl/
Sweden
http://ftp.du.se/CPAN/
ftp://ftp.du.se/pub/CPAN/
ftp://ftp.sunet.se/pub/lang/perl/CPAN/
Switzerland
ftp://ftp.danyk.ch/CPAN/
ftp://sunsite.cnlab-switch.ch/mirror/CPAN/
Turkey
ftp://sunsite.bilkent.edu.tr/pub/languages/CPAN/
North America
Canada
Alberta
http://sunsite.ualberta.ca/pub/Mirror/CPAN/
ftp://sunsite.ualberta.ca/pub/Mirror/CPAN/
Manitoba
http://theoryx5.uwinnipeg.ca/pub/CPAN/
ftp://theoryx5.uwinnipeg.ca/pub/CPAN/
Nova Scotia
ftp://cpan.chebucto.ns.ca/pub/CPAN/
Ontario
ftp://ftp.crc.ca/pub/packages/lang/perl/CPAN/
Mexico
http://www.msg.com.mx/CPAN/
ftp://ftp.msg.com.mx/pub/CPAN/
United States
Alabama
http://mirror.hiwaay.net/CPAN/
ftp://mirror.hiwaay.net/CPAN/
California
http://www.cpan.org/
ftp://ftp.cpan.org/CPAN/
ftp://cpan.nas.nasa.gov/pub/perl/CPAN/
ftp://ftp.digital.com/pub/plan/perl/CPAN/
http://www.kernel.org/pub/mirrors/cpan/
ftp://ftp.kernel.org/pub/mirrors/cpan/
http://www.perl.com/CPAN/
http://download.sourceforge.net/mirrors/CPAN/
Colorado
ftp://ftp.cs.colorado.edu/pub/perl/CPAN/
Florida
ftp://ftp.cise.ufl.edu/pub/perl/CPAN/
Georgia
ftp://ftp.twoguys.org/CPAN/
Illinois
http://www.neurogames.com/mirrors/CPAN
http://uiarchive.uiuc.edu/mirrors/ftp/ftp.cpan.org/pub/CPAN/
ftp://uiarchive.uiuc.edu/mirrors/ftp/ftp.cpan.org/pub/CPAN/
Indiana
ftp://ftp.uwsg.indiana.edu/pub/perl/CPAN/
http://cpan.nitco.com/
ftp://cpan.nitco.com/pub/CPAN/
ftp://cpan.in-span.net/
http://csociety-ftp.ecn.purdue.edu/pub/CPAN
ftp://csociety-ftp.ecn.purdue.edu/pub/CPAN
Kentucky
http://cpan.uky.edu/
ftp://cpan.uky.edu/pub/CPAN/
Massachusetts
ftp://ftp.ccs.neu.edu/net/mirrors/ftp.funet.fi/pub/languages/perl/CPAN/
ftp://ftp.iguide.com/pub/mirrors/packages/perl/CPAN/
New Jersey
ftp://ftp.cpanel.net/pub/CPAN/
New York
ftp://ftp.freesoftware.com/pub/perl/CPAN/
http://www.deao.net/mirrors/CPAN/
ftp://ftp.deao.net/pub/CPAN/
ftp://ftp.stealth.net/pub/mirrors/ftp.cpan.org/pub/CPAN/
http://mirror.nyc.anidea.com/CPAN/
ftp://mirror.nyc.anidea.com/pub/CPAN/
http://www.rge.com/pub/languages/perl/
ftp://ftp.rge.com/pub/languages/perl/
ftp://mirrors.cloud9.net/pub/mirrors/CPAN/
North Carolina
ftp://ftp.duke.edu/pub/perl/
Ohio
ftp://ftp.loaded.net/pub/CPAN/
Oklahoma
ftp://ftp.ou.edu/mirrors/CPAN/
Oregon
ftp://ftp.orst.edu/pub/packages/CPAN/
Pennsylvania
http://ftp.epix.net/CPAN/
ftp://ftp.epix.net/pub/languages/perl/
ftp://carroll.cac.psu.edu/pub/CPAN/
Tennessee
ftp://ftp.sunsite.utk.edu/pub/CPAN/
Texas
http://ftp.sedl.org/pub/mirrors/CPAN/
http://jhcloos.com/pub/mirror/CPAN/
ftp://jhcloos.com/pub/mirror/CPAN/
Utah
ftp://mirror.xmission.com/CPAN/
Virginia
http://mirrors.rcn.net/pub/lang/CPAN/
ftp://mirrors.rcn.net/pub/lang/CPAN/
ftp://ruff.cs.jmu.edu/pub/CPAN/
http://perl.Liquidation.com/CPAN/
Washington
http://cpan.llarian.net/
ftp://cpan.llarian.net/pub/CPAN/
ftp://ftp-mirror.internap.com/pub/CPAN/
ftp://ftp.spu.edu/pub/CPAN/
Oceania
Australia
http://ftp.planetmirror.com/pub/CPAN/
ftp://ftp.planetmirror.com/pub/CPAN/
ftp://mirror.aarnet.edu.au/pub/perl/CPAN/
ftp://cpan.topend.com.au/pub/CPAN/
New Zealand
ftp://ftp.auckland.ac.nz/pub/perl/CPAN/
South America
Argentina
ftp://mirrors.bannerlandia.com.ar/mirrors/CPAN/
Brazil
ftp://cpan.pop-mg.com.br/pub/CPAN/
ftp://ftp.matrix.com.br/pub/perl/
ftp://cpan.if.usp.br/pub/mirror/CPAN/
Chile
ftp://ftp.psinet.cl/pub/programming/perl/CPAN/
ftp://sunsite.dcc.uchile.cl/pub/lang/perl/
For an up-to-date listing of CPAN sites, see
http://www.cpan.org/SITES or ftp://www.cpan.org/SITES .
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" meth
ods), 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 mod
ule might set up an AUTOLOAD function to slurp in subrou
tine definitions on demand, but this is also transparent.
Only the .pm file is required to exist. See the perlsub
manpage, the perltoot manpage, and the AutoLoader manpage
for details about the AUTOLOAD mechanism.
Guidelines for Module Creation
Do similar modules already exist in some form?
If so, please try to reuse the existing modules either
in whole or by inheriting useful features into a new
class. If this is not practical try to get together
with the module authors to work on extending or
enhancing the functionality of the existing modules.
A perfect example is the plethora of packages in perl4
for dealing with command line options.
If you are writing a module to expand an already
existing set of modules, please coordinate with the
author of the package. It helps if you follow the
same naming scheme and module interaction scheme as
the original author.
Try to design the new module to be easy to extend and
reuse.
Try to "use warnings;" (or "use warnings qw(...);").
Remember that you can add "no warnings qw(...);" to
individual blocks of code that need less warnings.
Use blessed references. Use the two argument form of
bless to bless into the class name given as the first
parameter of the constructor, e.g.,:
sub new {
my $class = shift;
return bless {}, $class;
}
or even this if you'd like it to be used as either a
static or a virtual method.
sub new {
my $self = shift;
my $class = ref($self) || $self;
return bless {}, $class;
}
Pass arrays as references so more parameters can be
added later (it's also faster). Convert functions
into methods where appropriate. Split large methods
into smaller more flexible ones. Inherit methods from
other modules if appropriate.
Avoid class name tests like: "die "Invalid" unless ref
$ref eq 'FOO'". Generally you can delete the "eq
'FOO'" part with no harm at all. Let the objects look
after themselves! Generally, avoid hard-wired class
names as far as possible.
Avoid "$r->Class::func()" where using "@ISA=qw(...
Class ...)" and "$r->func()" would work (see the perl
bot manpage for more details).
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 $@ unless caller();
Does your module pass the 'empty subclass' test? If
you say "@SUBCLASS::ISA = qw(YOURCLASS);" your appli
cations should be able to use SUBCLASS in exactly the
same way as YOURCLASS. For example, does your appli
cation still work if you change: "$obj = new YOUR
CLASS;" into: "$obj = new SUBCLASS;" ?
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 the perlstyle(1) manual.
Always use -w.
Some simple style guidelines
The perlstyle manual supplied with Perl has many help
ful points.
Coding style is a matter of personal taste. Many peo
ple 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 $VarNames
LikeThis, especially for non-native speakers of
English. It's also a simple rule that works consis
tently 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 mod
ules normally begin with a capital letter and use
mixed case with no underscores (need to be short and
portable).
You may find it helpful to use letter case to indicate
the scope or nature of a variable. For example:
$ALL_CAPS_HERE constants only (beware clashes with Perl vars)
$Some_Caps_Here package-wide global/static
$no_caps_here function scope my() or local() variables
Function and method names seem to work best as all
lowercase. e.g., "$obj->as_string()".
You can use a leading underscore to indicate that a
variable or function should not be used outside the
package that defined it.
Select what to export.
Do NOT export method names!
Do NOT export anything else by default without a good
reason!
Exports pollute the namespace of the module user. If
you must export try to use @EXPORT_OK in preference to
@EXPORT and avoid short or common names to reduce the
risk of name clashes.
Generally anything not exported is still accessible
from outside the module using the Module
Name::item_name (or "$blessed_ref->method") syntax.
By convention you can use a leading underscore on
names to indicate informally that they are 'internal'
and not for public use.
(It is actually possible to get private functions by
saying: "my $subref = sub { ... }; &$subref;". But
there's no way to call that directly as a method,
because a method must have a name in the symbol
table.)
As a general rule, if the module is trying to be
object oriented then export nothing. If it's just a
collection of functions then @EXPORT_OK anything but
use @EXPORT with caution.
Select a name for the module.
This name should be as descriptive, accurate, and com
plete 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 mod
ules/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 nam
ing guide.
If adding a new module to a set, follow the original
author's standards for naming modules and the inter
face to methods in those modules.
If developing modules for private internal or project
specific use, that will never be released to the pub
lic, 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.
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 help
ful suggestions, is to ask someone who knows.
Comp.lang.perl.misc is read by just about all the peo
ple who develop modules and it's the best place to
ask.
All you need to do is post a short summary of the mod
ule, its purpose and interfaces. A few lines on each
of the main methods is probably enough. (If you post
the whole module it might be ignored by busy people -
generally the very people you want to read it!)
Don't worry about posting if you can't say when the
module will be ready - just say so in the message. It
might be worth inviting others to help you, they may
be able to complete it for you!
README and other Additional Files.
It's well known that software developers usually fully
document the software they write. If, however, the
world is in urgent need of your software and there is
not enough time to write the full documentation please
at least provide a README file containing:
A description of the module/package/exten
sion etc.
A copyright notice - see below.
Prerequisites - what else you may need to
have.
How to build it - possible changes to Make
file.PL etc.
How to install it.
Recent changes in this release, especially
incompatibilities
Changes / enhancements you plan to make in
the future.
If the README file seems to be getting too large you
may wish to split out some of the sections into sepa
rate files: INSTALL, Copying, ToDo etc.
Adding a Copyright Notice.
How you choose to license your work is a personal
decision. The general mechanism is to assert your
Copyright and then make a declaration of how oth
ers 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). 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 Copy
right.
Give the module a version/issue/release number.
To be fully compatible with the Exporter and Make
Maker modules you should store your module's ver
sion number in a non-my package variable called
$VERSION. This should be a floating point number
with at least two digits after the decimal (i.e.,
hundredths, e.g, "$VERSION = "0.01""). Don't use
a "1.3.2" style version. See the Exporter manpage
for details.
It may be handy to add a function or method to
retrieve the number. Use the number in announce
ments and archive file names when releasing the
module (ModuleName-1.02.tar.Z). See perldoc ExtU
tils::MakeMaker.pm for details.
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 possi
ble after uploading else your file may get deleted
automatically. Allow time for the file to be pro
cessed and/or check the file has been processed
before announcing its location.
FTP Archives for Perl Modules:
Follow the instructions and links on:
http://www.cpan.org/modules/00modlist.long.html
http://www.cpan.org/modules/04pause.html
or upload to one of these sites:
https://pause.kbx.de/pause/
http://pause.perl.org/pause/
and notify <modules@perl.org>.
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!
Take care when changing a released module.
Always strive to remain compatible with previous
released versions. Otherwise try to add a mecha
nism to revert to the old behavior if people rely
on it. Document incompatible changes.
Guidelines for Converting Perl 4 Library Scripts into Mod
ules
There is no requirement to convert anything.
If it ain't broke, don't fix it! Perl 4 library
scripts should continue to work with no problems. You
may need to make some minor changes (like escaping
non-array @'s in double quoted strings) but there is
no need to convert a .pl file into a Module for just
that.
Consider the implications.
All Perl applications that make use of the script will
need to be changed (slightly) if the script is con
verted into a module. Is it worth it unless you plan
to make other changes at the same time?
Make the most of the opportunity.
If you are going to convert the script to a module you
can use the opportunity to redesign the interface.
The guidelines for module creation above include many
of the issues you should consider.
The pl2pm utility will get you started.
This utility will read *.pl files (given as parame
ters) and write corresponding *.pm files. The pl2pm
utilities does the following:
Adds the standard Module prologue lines
Converts package specifiers from ' to ::
Converts die(...) to croak(...)
Several other minor changes
Being a mechanical process pl2pm is not bullet proof.
The converted code will need careful checking, espe
cially any package statements. Don't delete the orig
inal .pl file till the new .pm one works!
Guidelines for Reusing Application Code
Complete applications rarely belong in the Perl Module
Library.
Many applications contain some Perl code that could be
reused.
Help save the world! Share your code in a form that
makes it easy to reuse.
Break-out the reusable code into one or more separate
module files.
Take the opportunity to reconsider and redesign the
interfaces.
In some cases the 'application' can then be reduced to
a small
fragment of code built on top of the reusable modules.
In these cases the application could invoked as:
% perl -e 'use Module::Name; method(@ARGV)' ...
or
% perl -mModule::Name ... (in perl5.002 or higher)
NOTE
Perl does not enforce private and public parts of its mod
ules 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 provi
sions. But then you know when you "use RedefineTheWorld"
that you're redefining the world and willing to take the
consequences.
2001-03-18 perl v5.6.1 PERLMODLIB(1)
