perlfaq2 - man pages section 1: User Commands

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perlfaq2 (1)

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perlfaq2 - Obtaining and Learning about Perl

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Description

Perl Programmers Reference Guide PERLFAQ2(1)

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/

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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

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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.

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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

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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)

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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

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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/

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 August 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

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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
by 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
by 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

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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 ).

The Perl-Zeitung is a German-speaking magazine for Perl
beginners (see http://perl-zeitung.at.tf ).

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.

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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.

If "Module::CoreList" is not installed on your system, check
out http://perlpunks.de/corelist .

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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.

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

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courteous but is not required.

ATTRIBUTES
See attributes(5) for descriptions of the following
attributes:

+---------------+------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+------------------+
|Availability | runtime/perl-512 |
+---------------+------------------+
|Stability | Uncommitted |
+---------------+------------------+
NOTES
This software was built from source available at
https://java.net/projects/solaris-userland. The original
community source was downloaded from
http://www.cpan.org/src/5.0/perl-5.12.5.tar.bz2

Further information about this software can be found on the
open source community website at http://www.perl.org/.

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