NAME
perlfaq2 - Obtaining and Learning about Perl
DESCRIPTION
This section of the FAQ answers questions about where to find source
and documentation for Perl, support, and related matters.
What machines support perl? Where do I get it?
The standard release of perl (the one maintained by the perl
development team) is distributed only in source code form. You can
find the latest releases at http://www.cpan.org/src/README.html .
Perl builds and runs on a bewildering number of platforms. Virtually
all known and current Unix derivatives are supported (perl’s native
platform), as are other systems like VMS, DOS, OS/2, Windows, QNX,
BeOS, OS X, MPE/iX and the Amiga.
Binary distributions for some proprietary platforms can be found
http://www.cpan.org/ports/ directory. Because these are not part of the
standard distribution, they may and in fact do differ from the base
perl port in a variety of ways. You’ll have to check their respective
release notes to see just what the differences are. These differences
can be either positive (e.g. extensions for the features of the
particular platform that are not supported in the source release of
perl) or negative (e.g. might be based upon a less current source
release of perl).
How can I get a binary version of perl?
(contributed by brian d foy)
ActiveState: Windows, Linux, Mac OS X, Solaris, AIX and HP-UX
http://www.activestate.com/
Sunfreeware.com: Solaris 2.5 to Solaris 10 (SPARC and x86)
http://www.sunfreeware.com/
Strawberry Perl: Windows, Perl 5.8.8 and 5.10.0
http://www.strawberryperl.com
IndigoPerl: Windows
http://indigostar.com/
I don’t have a C compiler. How can I build my own Perl interpreter?
Since you don’t have a C compiler, you’re doomed and your vendor should
be sacrificed to the Sun gods. But that doesn’t help you.
What you need to do is get a binary version of gcc for your system
first. Consult the Usenet FAQs for your operating system for
information on where to get such a binary version.
You might look around the net for a pre-built binary of Perl (or a C
compiler!) that meets your needs, though:
For Windows, Vanilla Perl ( http://vanillaperl.com/ ) and Strawberry
Perl ( http://strawberryperl.com/ ) come with a bundled C compiler.
ActivePerl is a pre-compiled version of Perl ready-to-use.
For Sun systems, SunFreeware.com provides binaries of most popular
applications, including compilers and Perl.
I copied the perl binary from one machine to another, but scripts don’t
work.
That’s probably because you forgot libraries, or library paths differ.
You really should build the whole distribution on the machine it will
eventually live on, and then type "make install". Most other
approaches are doomed to failure.
One simple way to check that things are in the right place is to print
out the hard-coded @INC that perl looks through for libraries:
% perl -le 'print for @INC'
If this command lists any paths that don’t exist on your system, then
you may need to move the appropriate libraries to these locations, or
create symbolic links, aliases, or shortcuts appropriately. @INC is
also printed as part of the output of
% perl -V
You might also want to check out "How do I keep my own module/library
directory?" in perlfaq8.
I grabbed the sources and tried to compile but gdbm/dynamic
loading/malloc/linking/... failed. How do I make it work?
Read the INSTALL file, which is part of the source distribution. It
describes in detail how to cope with most idiosyncrasies that the
Configure script can’t work around for any given system or
architecture.
What modules and extensions are available for Perl? What is CPAN? What
does CPAN/src/... mean?
CPAN stands for Comprehensive Perl Archive Network, a multi-gigabyte
archive replicated on hundreds of machines all over the world. CPAN
contains source code, non-native ports, documentation, scripts, and
many third-party modules and extensions, designed for everything from
commercial database interfaces to keyboard/screen control to web
walking and CGI scripts. The master web site for CPAN is
http://www.cpan.org/ and there is the CPAN Multiplexer at
http://www.cpan.org/CPAN.html which will choose a mirror near you via
DNS. See http://www.perl.com/CPAN (without a slash at the end) for how
this process works. Also, http://mirror.cpan.org/ has a nice interface
to the http://www.cpan.org/MIRRORED.BY mirror directory.
See the CPAN FAQ at http://www.cpan.org/misc/cpan-faq.html for answers
to the most frequently asked questions about CPAN including how to
become a mirror.
CPAN/path/... is a naming convention for files available on CPAN sites.
CPAN indicates the base directory of a CPAN mirror, and the rest of the
path is the path from that directory to the file. For instance, if
you’re using ftp://ftp.funet.fi/pub/languages/perl/CPAN as your CPAN
site, the file CPAN/misc/japh is downloadable as
ftp://ftp.funet.fi/pub/languages/perl/CPAN/misc/japh .
Considering that, as of 2006, there are over ten thousand existing
modules in the archive, one probably exists to do nearly anything you
can think of. Current categories under CPAN/modules/by-category/
include Perl core modules; development support; operating system
interfaces; networking, devices, and interprocess communication; data
type utilities; database interfaces; user interfaces; interfaces to
other languages; filenames, file systems, and file locking;
internationalization and locale; world wide web support; server and
daemon utilities; archiving and compression; image manipulation; mail
and news; control flow utilities; filehandle and I/O; Microsoft Windows
modules; and miscellaneous modules.
See http://www.cpan.org/modules/00modlist.long.html or
http://search.cpan.org/ for a more complete list of modules by
category.
CPAN is a free service and is not affiliated with O’Reilly Media.
Is there an ISO or ANSI certified version of Perl?
Certainly not. Larry expects that he’ll be certified before Perl is.
Where can I get information on Perl?
The complete Perl documentation is available with the Perl
distribution. If you have Perl installed locally, you probably have
the documentation installed as well: type "man perl" if you’re on a
system resembling Unix. This will lead you to other important man
pages, including how to set your $MANPATH. If you’re not on a Unix
system, access to the documentation will be different; for example,
documentation might only be in HTML format. All proper perl
installations have fully-accessible documentation.
You might also try "perldoc perl" in case your system doesn’t have a
proper man command, or it’s been misinstalled. If that doesn’t work,
try looking in /usr/local/lib/perl5/pod for documentation.
If all else fails, consult http://perldoc.perl.org/ which has the
complete documentation in HTML and PDF format.
Many good books have been written about Perl--see the section later in
perlfaq2 for more details.
Tutorial documents are included in current or upcoming Perl releases
include perltoot for objects or perlboot for a beginner’s approach to
objects, perlopentut for file opening semantics, perlreftut for
managing references, perlretut for regular expressions, perlthrtut for
threads, perldebtut for debugging, and perlxstut for linking C and Perl
together. There may be more by the time you read this. These URLs
might also be useful:
http://perldoc.perl.org/
http://bookmarks.cpan.org/search.cgi?cat=Training%2FTutorials
What are the Perl newsgroups on Usenet? Where do I post questions?
Several groups devoted to the Perl language are on Usenet:
comp.lang.perl.announce Moderated announcement group
comp.lang.perl.misc High traffic general Perl discussion
comp.lang.perl.moderated Moderated discussion group
comp.lang.perl.modules Use and development of Perl modules
comp.lang.perl.tk Using Tk (and X) from Perl
Some years ago, comp.lang.perl was divided into those groups, and
comp.lang.perl itself officially removed. While that group may still
be found on some news servers, it is unwise to use it, because postings
there will not appear on news servers which honour the official list of
group names. Use comp.lang.perl.misc for topics which do not have a
more-appropriate specific group.
There is also a Usenet gateway to Perl mailing lists sponsored by
perl.org at nntp://nntp.perl.org , a web interface to the same lists at
http://nntp.perl.org/group/ and these lists are also available under
the "perl.*" hierarchy at http://groups.google.com . Other groups are
listed at http://lists.perl.org/ ( also known as http://lists.cpan.org/
).
A nice place to ask questions is the PerlMonks site,
http://www.perlmonks.org/ , or the Perl Beginners mailing list
http://lists.perl.org/showlist.cgi?name=beginners .
Note that none of the above are supposed to write your code for you:
asking questions about particular problems or general advice is fine,
but asking someone to write your code for free is not very cool.
Where should I post source code?
You should post source code to whichever group is most appropriate, but
feel free to cross-post to comp.lang.perl.misc. If you want to cross-
post to alt.sources, please make sure it follows their posting
standards, including setting the Followup-To header line to NOT include
alt.sources; see their FAQ (
http://www.faqs.org/faqs/alt-sources-intro/ ) for details.
If you’re just looking for software, first use Google (
http://www.google.com ), Google’s usenet search interface (
http://groups.google.com ), and CPAN Search ( http://search.cpan.org
). This is faster and more productive than just posting a request.
Perl Books
A number of books on Perl and/or CGI programming are available. A few
of these are good, some are OK, but many aren’t worth your money.
There is a list of these books, some with extensive reviews, at
http://books.perl.org/ . If you don’t see your book listed here, you
can write to perlfaq-workers@perl.org .
The incontestably definitive reference book on Perl, written by the
creator of Perl, is Programming Perl:
Programming Perl (the "Camel Book"):
by Larry Wall, Tom Christiansen, and Jon Orwant
ISBN 0-596-00027-8 [3rd edition July 2000]
http://www.oreilly.com/catalog/pperl3/
(English, translations to several languages are also available)
The companion volume to the Camel containing thousands of real-world
examples, mini-tutorials, and complete programs is:
The Perl Cookbook (the "Ram Book"):
by Tom Christiansen and Nathan Torkington,
with Foreword by Larry Wall
ISBN 0-596-00313-7 [2nd Edition August 2003]
http://www.oreilly.com/catalog/perlckbk2/
If you’re already a seasoned programmer, then the Camel Book might
suffice for you to learn Perl. If you’re not, check out the Llama
book:
Learning Perl
by Randal L. Schwartz, Tom Phoenix, and brian d foy
ISBN 0-596-10105-8 [4th edition July 2005]
http://www.oreilly.com/catalog/learnperl4/
And for more advanced information on writing larger programs, presented
in the same style as the Llama book, continue your education with the
Alpaca book:
Intermediate Perl (the "Alpaca Book")
by Randal L. Schwartz and brian d foy, with Tom Phoenix (foreword by Damian Conway)
ISBN 0-596-10206-2 [1st edition March 2006]
http://www.oreilly.com/catalog/lrnperlorm/
Addison-Wesley ( http://www.awlonline.com/ ) and Manning (
http://www.manning.com/ ) are also publishers of some fine Perl books
such as Object Oriented Programming with Perl by Damian Conway and
Network Programming with Perl by Lincoln Stein.
An excellent technical book discounter is Bookpool at
http://www.bookpool.com/ where a 30% discount or more is not unusual.
What follows is a list of the books that the FAQ authors found
personally useful. Your mileage may (but, we hope, probably won’t)
vary.
Recommended books on (or mostly on) Perl follow.
References
Programming Perl
by Larry Wall, Tom Christiansen, and Jon Orwant
ISBN 0-596-00027-8 [3rd edition July 2000]
http://www.oreilly.com/catalog/pperl3/
Perl 5 Pocket Reference
by Johan Vromans
ISBN 0-596-00374-9 [4th edition July 2002]
http://www.oreilly.com/catalog/perlpr4/
Tutorials
Beginning Perl
by James Lee
ISBN 1-59059-391-X [2nd edition August 2004]
http://apress.com/book/bookDisplay.html?bID=344
Elements of Programming with Perl
by Andrew L. Johnson
ISBN 1-884777-80-5 [1st edition October 1999]
http://www.manning.com/johnson/
Learning Perl
by Randal L. Schwartz, Tom Phoenix, and brian d foy
ISBN 0-596-52010-7 [5th edition June 2008]
http://oreilly.com/catalog/9780596520106/
Intermediate Perl (the "Alpaca Book")
by Randal L. Schwartz and brian d foy, with Tom Phoenix (foreword by Damian Conway)
ISBN 0-596-10206-2 [1st edition March 2006]
http://www.oreilly.com/catalog/intermediateperl/
Mastering Perl
by brian d foy
ISBN 0-596-52724-1 [1st edition July 2007]
http://www.oreilly.com/catalog/9780596527242/
Task-Oriented
Writing Perl Modules for CPAN
by Sam Tregar
ISBN 1-59059-018-X [1st edition Aug 2002]
http://apress.com/book/bookDisplay.html?bID=14
The Perl Cookbook
by Tom Christiansen and Nathan Torkington
with foreword by Larry Wall
ISBN 1-56592-243-3 [1st edition August 1998]
http://www.oreilly.com/catalog/cookbook/
Effective Perl Programming
by Joseph Hall
ISBN 0-201-41975-0 [1st edition 1998]
http://www.awl.com/
Real World SQL Server Administration with Perl
by Linchi Shea
ISBN 1-59059-097-X [1st edition July 2003]
http://apress.com/book/bookDisplay.html?bID=171
Special Topics
Perl Best Practices
by Damian Conway
ISBN: 0-596-00173-8 [1st edition July 2005]
http://www.oreilly.com/catalog/perlbp/
Higher Order Perl
by Mark-Jason Dominus
ISBN: 1558607013 [1st edition March 2005]
http://hop.perl.plover.com/
Perl 6 Now: The Core Ideas Illustrated with Perl 5
by Scott Walters
ISBN 1-59059-395-2 [1st edition December 2004]
http://apress.com/book/bookDisplay.html?bID=355
Mastering Regular Expressions
by Jeffrey E. F. Friedl
ISBN 0-596-00289-0 [2nd edition July 2002]
http://www.oreilly.com/catalog/regex2/
Network Programming with Perl
by Lincoln Stein
ISBN 0-201-61571-1 [1st edition 2001]
http://www.awlonline.com/
Object Oriented Perl
Damian Conway
with foreword by Randal L. Schwartz
ISBN 1-884777-79-1 [1st edition August 1999]
http://www.manning.com/conway/
Data Munging with Perl
Dave Cross
ISBN 1-930110-00-6 [1st edition 2001]
http://www.manning.com/cross
Mastering Perl/Tk
by Steve Lidie and Nancy Walsh
ISBN 1-56592-716-8 [1st edition January 2002]
http://www.oreilly.com/catalog/mastperltk/
Extending and Embedding Perl
by Tim Jenness and Simon Cozens
ISBN 1-930110-82-0 [1st edition August 2002]
http://www.manning.com/jenness
Perl Debugger Pocket Reference
by Richard Foley
ISBN 0-596-00503-2 [1st edition January 2004]
http://www.oreilly.com/catalog/perldebugpr/
Pro Perl Debugging
by Richard Foley with Andy Lester
ISBN 1-59059-454-1 [1st edition July 2005]
http://www.apress.com/book/view/1590594541
Which magazines have Perl content?
The Perl Review ( http://www.theperlreview.com ) focuses on Perl almost
completely (although it sometimes sneaks in an article about another
language). There’s also $foo Magazin, a german magazine dedicated to
Perl, at ( http://www.foo-magazin.de ).
Magazines that frequently carry quality articles on Perl include The
Perl Review ( http://www.theperlreview.com ), Unix Review (
http://www.unixreview.com/ ), Linux Magazine (
http://www.linuxmagazine.com/ ), and Usenix’s newsletter/magazine to
its members, login: ( http://www.usenix.org/ )
The Perl columns of Randal L. Schwartz are available on the web at
http://www.stonehenge.com/merlyn/WebTechniques/ ,
http://www.stonehenge.com/merlyn/UnixReview/ , and
http://www.stonehenge.com/merlyn/LinuxMag/ .
The first (and for a long time, only) periodical devoted to All Things
Perl, The Perl Journal contains tutorials, demonstrations, case
studies, announcements, contests, and much more. TPJ has columns on
web development, databases, Win32 Perl, graphical programming, regular
expressions, and networking, and sponsors the Obfuscated Perl Contest
and the Perl Poetry Contests. Beginning in November 2002, TPJ moved to
a reader-supported monthly e-zine format in which subscribers can
download issues as PDF documents. In 2006, TPJ merged with Dr. Dobbs
Journal (online edition). To read old TPJ articles, see
http://www.ddj.com/ .
What mailing lists are there for Perl?
Most of the major modules (Tk, CGI, libwww-perl) have their own mailing
lists. Consult the documentation that came with the module for
subscription information.
A comprehensive list of Perl related mailing lists can be found at:
http://lists.perl.org/
Where are the archives for comp.lang.perl.misc?
The Google search engine now carries archived and searchable newsgroup
content.
http://groups.google.com/group/comp.lang.perl.misc/topics
If you have a question, you can be sure someone has already asked the
same question at some point on c.l.p.m. It requires some time and
patience to sift through all the content but often you will find the
answer you seek.
Where can I buy a commercial version of perl?
In a real sense, perl already is commercial software: it has a license
that you can grab and carefully read to your manager. It is distributed
in releases and comes in well-defined packages. There is a very large
user community and an extensive literature. The comp.lang.perl.*
newsgroups and several of the mailing lists provide free answers to
your questions in near real-time. Perl has traditionally been
supported by Larry, scores of software designers and developers, and
myriad programmers, all working for free to create a useful thing to
make life better for everyone.
However, these answers may not suffice for managers who require a
purchase order from a company whom they can sue should anything go
awry. Or maybe they need very serious hand-holding and contractual
obligations. Shrink-wrapped CDs with perl on them are available from
several sources if that will help. For example, many Perl books
include a distribution of perl, as do the O’Reilly Perl Resource Kits
(in both the Unix flavor and in the proprietary Microsoft flavor); the
free Unix distributions also all come with perl.
Where do I send bug reports?
(contributed by brian d foy)
First, ensure that you’ve found an actual bug. Second, ensure you’ve
found an actual bug.
If you’ve found a bug with the perl interpreter or one of the modules
in the standard library (those that come with Perl), you can use the
"perlbug" utility that comes with Perl (>= 5.004). It collects
information about your installation to include with your message, then
sends the message to the right place.
To determine if a module came with your version of Perl, you can use
the "Module::CoreList" module. It has the information about the modules
(with their versions) included with each release of Perl.
Every CPAN module has a bug tracker set up in RT, http://rt.cpan.org .
You can submit bugs to RT either through its web interface or by email.
To email a bug report, send it to bug-<distribution-name>@rt.cpan.org .
For example, if you wanted to report a bug in "Business::ISBN", you
could send a message to bug-Business-ISBN@rt.cpan.org .
Some modules might have special reporting requirements, such as a
Sourceforge or Google Code tracking system, so you should check the
module documentation too.
What is perl.com? Perl Mongers? pm.org? perl.org? cpan.org?
Perl.com at http://www.perl.com/ is part of the O’Reilly Network, a
subsidiary of O’Reilly Media.
The Perl Foundation is an advocacy organization for the Perl language
which maintains the web site http://www.perl.org/ as a general advocacy
site for the Perl language. It uses the domain to provide general
support services to the Perl community, including the hosting of
mailing lists, web sites, and other services. There are also many
other sub-domains for special topics like learning Perl, Perl news,
jobs in Perl, such as:
http://learn.perl.org/
http://use.perl.org/
http://jobs.perl.org/
http://lists.perl.org/
Perl Mongers uses the pm.org domain for services related to Perl user
groups, including the hosting of mailing lists and web sites. See the
Perl user group web site at http://www.pm.org/ for more information
about joining, starting, or requesting services for a Perl user group.
http://www.cpan.org/ is the Comprehensive Perl Archive Network, a
replicated worldwide repository of Perl software, see the What is CPAN?
question earlier in this document.
REVISION
Revision: $Revision$
Date: $Date$
See perlfaq for source control details and availability.
AUTHOR AND COPYRIGHT
Copyright (c) 1997-2009 Tom Christiansen, Nathan Torkington, and other
authors as noted. All rights reserved.
This documentation is free; you can redistribute it and/or modify it
under the same terms as Perl itself.
Irrespective of its distribution, all code examples here are in the
public domain. You are permitted and encouraged to use this code and
any derivatives thereof in your own programs for fun or for profit as
you see fit. A simple comment in the code giving credit to the FAQ
would be courteous but is not required.