PERLFAQ2(1)

NAME
perlfaq2 - Obtaining and Learning about Perl ($Revision: 1.32 $, $Date: 1999/10/14 18:46:09 $)

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 this at http://www.cpan.org/src/latest.tar.gz , which is in a standard Internet format (a gzipped archive in POSIX tar format).

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, including Apple systems, 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?
If you don't have a C compiler because your vendor for whatever reasons did not include one with your system, the best thing to do is grab a binary version of gcc from the net and use that to compile perl with. CPAN only has binaries for systems that are terribly hard to get free compilers for, not for Unix systems.

Some URLs that might help you are:

    http://www.cpan.org/ports/
    http://language.perl.com/info/software.html
Someone looking for a Perl for Win16 might look to Laszlo Molnar's djgpp port in http://www.cpan.org/ports/#msdos , which comes with clear installation instructions. A simple installation guide for MS-DOS using Ilya Zakharevich's OS/2 port is available at http://www.cs.ruu.nl/%7Epiet/perl5dos.html and similarly for Windows 3.1 at http://www.cs.ruu.nl/%7Epiet/perlwin3.html .

  I don't have a C compiler on my system. How can I compile perl?
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.

  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 -e 'print join("\n",@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 the How do I keep my own module/library directory? entry in the perlfaq8 manpage.

  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 ~700mb archive replicated on nearly 200 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.perl.com/CPAN/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 there are close to two 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.

  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.cpan.org/ or http://www.perldoc.com/ both offer the complete documentation in html format.

Many good books have been written about Perl--see the section below for more details.

Tutorial documents are included in current or upcoming Perl releases include the perltoot manpage for objects or the perlboot manpage for a beginner's approach to objects, the perlopentut manpage for file opening semantics, the perlreftut manpage for managing references, the perlretut manpage for regular expressions, the perlthrtut manpage for threads, the perldebtut manpage for debugging, and the perlxstut manpage for linking C and Perl together. There may be more by the time you read this. The following URLs might also be of assistance:

    http://perldoc.cpan.org/
    http://www.perldoc.com/
    http://reference.perl.com/query.cgi?tutorials
    http://bookmarks.cpan.org/search.cgi?cat=Training%2FTutorials

  What are the Perl newsgroups on Usenet? Where do I post questions?
The now defunct comp.lang.perl newsgroup has been superseded by the following groups:

    comp.lang.perl.announce             Moderated announcement group
    comp.lang.perl.misc                 Very busy group about Perl in general
    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
    comp.infosystems.www.authoring.cgi  Writing CGI scripts for the Web.
There is also Usenet gateway to the mailing list used by the crack Perl development team (perl5-porters) at news://news.perl.com/perl.porters-gw/ .

  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), Deja (http://www.deja.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. Tom Christiansen maintains a list of these books, some with extensive reviews, at http://www.perl.com/perl/critiques/index.html .

The incontestably definitive reference book on Perl, written by the creator of Perl, is now (July 2000) in its third edition:

    Programming Perl (the "Camel Book"):
        by Larry Wall, Tom Christiansen, and Jon Orwant
        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 1-56592-243-3 [1st Edition August 1998]
        http://perl.oreilly.com/cookbook/
If you're already a hard-core systems programmer, then the Camel Book might suffice for you to learn Perl from. If you're not, check out

    Learning Perl (the "Llama Book"):
        by Randal Schwartz and Tom Christiansen
                    with Foreword by Larry Wall
        ISBN 1-56592-284-0 [2nd Edition July 1997]
        http://www.oreilly.com/catalog/lperl2/
Despite the picture at the URL above, the second edition of "Llama Book" really has a blue cover and was updated for the 5.004 release of Perl. Various foreign language editions are available, including Learning Perl on Win32 Systems (the "Gecko Book").

If you're not an accidental programmer, but a more serious and possibly even degreed computer scientist who doesn't need as much hand-holding as we try to provide in the Llama or its defurred cousin the Gecko, please check out the delightful book, Perl: The Programmer's Companion, written by Nigel Chapman.

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 0-596-00032-4 [3rd edition May 2000]
            http://www.oreilly.com/catalog/perlpr3/
        Perl in a Nutshell
            by Ellen Siever, Stephan Spainhour, and Nathan Patwardhan
            ISBN 1-56592-286-7 [1st edition December 1998]
            http://www.oreilly.com/catalog/perlnut/

Tutorials
        Elements of Programming with Perl
            by Andrew L. Johnson
            ISBN 1884777805 [1st edition October 1999]
            http://www.manning.com/Johnson/
        Learning Perl
            by Randal L. Schwartz and Tom Christiansen
                with foreword by Larry Wall
            ISBN 1-56592-284-0 [2nd edition July 1997]
            http://www.oreilly.com/catalog/lperl2/
        Learning Perl on Win32 Systems
            by Randal L. Schwartz, Erik Olson, and Tom Christiansen,
                with foreword by Larry Wall
            ISBN 1-56592-324-3 [1st edition August 1997]
            http://www.oreilly.com/catalog/lperlwin/
        Perl: The Programmer's Companion
            by Nigel Chapman
            ISBN 0-471-97563-X  [1st edition October 1997]
            http://catalog.wiley.com/title.cgi?isbn=047197563X
        Cross-Platform Perl
            by Eric Foster-Johnson
            ISBN 1-55851-483-X [2nd edition September 2000]
            http://www.pconline.com/~erc/perlbook.htm
        MacPerl: Power and Ease
            by Vicki Brown and Chris Nandor,
                with foreword by Matthias Neeracher
            ISBN 1-881957-32-2 [1st edition May 1998]
            http://www.macperl.com/ptf_book/

Task-Oriented
        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/

Special Topics
        Mastering Regular Expressions
            by Jeffrey E. F. Friedl
            ISBN 1-56592-257-3 [1st edition January 1997]
            http://www.oreilly.com/catalog/regex/
        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 1884777791 [1st edition August 1999]
            http://www.manning.com/Conway/
        Data Munging with Perl
            Dave Cross
            ISBN 1930110006 [1st edition 2001]
            http://www.manning.com/cross
        Learning Perl/Tk
            by Nancy Walsh
            ISBN 1-56592-314-6 [1st edition January 1999]
            http://www.oreilly.com/catalog/lperltk/

  Perl in Magazines
The first and only periodical devoted to All Things Perl, The Perl Journal contained tutorials, demonstrations, case studies, announcements, contests, and much more. TPJ had columns on web development, databases, Win32 Perl, graphical programming, regular expressions, and networking, and sponsored the Obfuscated Perl Contest. Sadly, this publication is no longer in circulation, but should it be resurrected, it will most likely be announced on http://use.perl.org/ .

Beyond this, magazines that frequently carry high-quality articles on Perl are Web Techniques (see http://www.webtechniques.com/), Performance Computing (http://www.performance-computing.com/), and Usenix's newsletter/magazine to its members, login:, at http://www.usenix.org/. Randal's Web Technique's columns are available on the web at http://www.stonehenge.com/merlyn/WebTechniques/ .

  Perl on the Net: FTP and WWW Access
To get the best performance, pick a site from the list below and use it to grab the complete list of mirror sites which is at /CPAN/MIRRORED.BY or at http://mirror.cpan.org/. From there you can find the quickest site for you. Remember, the following list is not the complete list of CPAN mirrors (the complete list contains 165 sites as of January 2001):

  http://www.cpan.org/
  http://www.perl.com/CPAN/
  http://download.sourceforge.net/mirrors/CPAN/
  ftp://ftp.digital.com/pub/plan/perl/CPAN/
  ftp://ftp.flirble.org/pub/languages/perl/CPAN/
  ftp://ftp.uvsq.fr/pub/perl/CPAN/
  ftp://ftp.funet.fi/pub/languages/perl/CPAN/
  ftp://ftp.dti.ad.jp/pub/lang/CPAN/
  ftp://mirror.aarnet.edu.au/pub/perl/CPAN/
  ftp://cpan.if.usp.br/pub/mirror/CPAN/
One may also use xx.cpan.org where "xx" is the 2-letter country code for your domain; e.g. Australia would use au.cpan.org.

  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.

        http://lists.cpan.org/

  Archives of comp.lang.perl.misc
Have you tried Deja or AltaVista? Those are the best archives. Just look up "*perl*" as a newsgroup.

    http://www.deja.com/dnquery.xp?QRY=&DBS=2&ST=PS&defaultOp=AND&LNG=ALL&format=terse&showsort=date&maxhits=25&subjects=&groups=*perl*&authors=&fromdate=&todate=
You might want to trim that down a bit, though.

You'll probably want more a sophisticated query and retrieval mechanism than a file listing, preferably one that allows you to retrieve articles using a fast-access indices, keyed on at least author, date, subject, thread (as in "trn") and probably keywords. The best solution the FAQ authors know of is the MH pick command, but it is very slow to select on 18000 articles.

If you have, or know where can be found, the missing sections, please let perlfaq-suggestions@perl.com know.

  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 myriads of 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.

Alternatively, you can purchase commercial incidence based support through the Perl Clinic. The following is a commercial from them:

"The Perl Clinic is a commercial Perl support service operated by ActiveState Tool Corp. and The Ingram Group. The operators have many years of in-depth experience with Perl applications and Perl internals on a wide range of platforms.

"Through our group of highly experienced and well-trained support engineers, we will put our best effort into understanding your problem, providing an explanation of the situation, and a recommendation on how to proceed."

Contact The Perl Clinic at

    www.PerlClinic.com
    North America Pacific Standard Time (GMT-8)
    Tel:    1 604 606-4611 hours 8am-6pm
    Fax:    1 604 606-4640
    Europe (GMT)
    Tel:    00 44 1483 862814
    Fax:    00 44 1483 862801
See also www.perl.com for updates on tutorials, training, and support.

  Where do I send bug reports?
If you are reporting a bug in the perl interpreter or the modules shipped with Perl, use the perlbug program in the Perl distribution or mail your report to perlbug@perl.org .

If you are posting a bug with a non-standard port (see the answer to "What platforms is Perl available for?"), a binary distribution, or a non-standard module (such as Tk, CGI, etc), then please see the documentation that came with it to determine the correct place to post bugs.

Read the perlbug(1) man page (perl5.004 or later) for more information.

  What is perl.com? Perl Mongers? pm.org? perl.org?
The Perl Home Page at http://www.perl.com/ is currently hosted on a T3 line courtesy of Songline Systems, a software-oriented subsidiary of O'Reilly and Associates. Other starting points include

    http://language.perl.com/
    http://conference.perl.com/
    http://reference.perl.com/
Perl Mongers 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.

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.

Perl Mongers also maintain the perl.org domain to provide general support services to the Perl community, including the hosting of mailing lists, web sites, and other services. The web site http://www.perl.org/ is a general advocacy site for the Perl language, and there are many other sub-domains for special topics, such as

    http://bugs.perl.org/
    http://history.perl.org/
    http://lists.perl.org/
    http://news.perl.org/
    http://use.perl.org/

AUTHOR AND COPYRIGHT
Copyright (c) 1997-2001 Tom Christiansen and Nathan Torkington. All rights reserved.

When included as an integrated part of the Standard Distribution of Perl or of its documentation (printed or otherwise), this works is covered under Perl's Artistic License. For separate distributions of all or part of this FAQ outside of that, see the perlfaq manpage.

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.