NAME

perlfaq2 - Obtaining and Learning about Perl ($Revision: 1.25 $, $Date: 1998/08/05 11:47:25 $)


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.perl.com/CPAN/src/latest.tar.gz, which in 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 proprietary systems like VMS, DOS, OS/2, Windows, QNX, BeOS, and the Amiga. There are also the beginnings of support for MPE/iX.

Binary distributions for some proprietary platforms, including Apple systems can be found http://www.perl.com/CPAN/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).

A useful FAQ for Win32 Perl users is http://www.endcontsw.com/people/evangelo/Perl_for_Win32_FAQ.html


How can I get a binary version of Perl?

If you don't have a C compiler because for whatever reasons your vendor 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.

Your first stop should be http://www.perl.com/CPAN/ports to see what information is already available. A simple installation guide for MS-DOS is available at http://www.cs.ruu.nl/~piet/perl5dos.html , and similarly for Windows 3.1 at http://www.cs.ruu.nl/~piet/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 which perl is looking for.

        perl -e 'print join("\n",@INC)'

If this command lists any paths which don't exist on your system, then you may need to move the appropriate libraries to these locations, or create symlinks, aliases, or shortcuts appropriately.

You might also want to check out How do I keep my own module/library directory?.


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 idiosyncracies 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 huge archive replicated on dozens 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 machine for CPAN is ftp://ftp.funet.fi/pub/languages/perl/CPAN/, but you can use the address http://www.perl.com/CPAN/CPAN.html to fetch a copy from a ``site near you''. See http://www.perl.com/CPAN (without a slash at the end) for how this process works.

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 file is downloadable as ftp://ftp.funet.fi/pub/languages/perl/CPAN/misc/japh .

Considering that there are hundreds of 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.


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, it might be only in HTML format. But 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 the CPAN/doc directory, which contains the complete documentation in various formats, including native pod, troff, html, and plain text. There's also a web page at http://www.perl.com/perl/info/documentation.html that might help.

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


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.

Actually, the moderated group hasn't passed yet, but we're keeping our fingers crossed.

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 for details.

If you're just looking for software, first use Alta Vista, Deja News, and search CPAN. 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 in its second edition:

    Programming Perl (the "Camel Book"):
        Authors: Larry Wall, Tom Christiansen, and Randal Schwartz
        ISBN 1-56592-149-6      (English)
        ISBN 4-89052-384-7      (Japanese)
        URL: http://www.oreilly.com/catalog/pperl2/
    (French, German, Italian, and Hungarian translations also
    available)

The companion volume to the Camel containing thousands of real-world examples, mini-tutorials, and complete programs (first premiering at the 1998 Perl Conference), is:

    The Perl Cookbook (the "Ram Book"):
        Authors: Tom Christiansen and Nathan Torkington,
                    with Foreword by Larry Wall
        ISBN: 1-56592-243-3
        URL:  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. But if you're not, check out:

    Learning Perl (the "Llama Book"):
        Authors: Randal Schwartz and Tom Christiansen
                    with Foreword by Larry Wall
        ISBN: 1-56592-284-0
        URL:  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 is 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.

You can order O'Reilly books directly from O'Reilly & Associates, 1-800-998-9938. Local/overseas is 1-707-829-0515. If you can locate an O'Reilly order form, you can also fax to 1-707-829-0104. See http://www.ora.com/ on the Web.

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 muchly on) Perl follow; those marked with a star may be ordered from O'Reilly.

References

    *Programming Perl
        by Larry Wall, Tom Christiansen, and Randal L. Schwartz

    *Perl 5 Desktop Reference
        By Johan Vromans
Tutorials

*Learning Perl [2nd edition] by Randal L. Schwartz and Tom Christiansen with foreword by Larry Wall

    *Learning Perl on Win32 Systems
        by Randal L. Schwartz, Erik Olson, and Tom Christiansen,
            with foreword by Larry Wall

    Perl: The Programmer's Companion
        by Nigel Chapman

    Cross-Platform Perl
        by Eric F. Johnson

    MacPerl: Power and Ease
        by Vicki Brown and Chris Nandor, foreword by Matthias Neeracher
Task-Oriented

    *The Perl Cookbook
        by Tom Christiansen and Nathan Torkington
            with foreword by Larry Wall

    Perl5 Interactive Course [2nd edition]
        by Jon Orwant

    *Advanced Perl Programming
        by Sriram Srinivasan

    Effective Perl Programming
        by Joseph Hall
Special Topics

    *Mastering Regular Expressions
        by Jeffrey Friedl

    How to Set up and Maintain a World Wide Web Site [2nd edition]
        by Lincoln Stein


Perl in Magazines

The first and 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. It is published quarterly under the gentle hand of its editor, Jon Orwant. See http://www.tpj.com/ or send mail to subscriptions@tpj.com.

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 (and possibly cheapest) performance, pick a site from the list below and use it to grab the complete list of mirror sites. From there you can find the quickest site for you. Remember, the following list is not the complete list of CPAN mirrors.

  http://www.perl.com/CPAN      (redirects to another mirror)
  http://www.perl.org/CPAN
  ftp://ftp.funet.fi/pub/languages/perl/CPAN/
  http://www.cs.ruu.nl/pub/PERL/CPAN/
  ftp://ftp.cs.colorado.edu/pub/perl/CPAN/


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. The following are a list of mailing lists related to perl itself.

If you subscribe to a mailing list, it behooves you to know how to unsubscribe from it. Strident pleas to the list itself to get you off will not be favorably received.

MacPerl

There is a mailing list for discussing Macintosh Perl. Contact ``mac-perl-request@iis.ee.ethz.ch''.

Also see Matthias Neeracher's (the creator and maintainer of MacPerl) webpage at http://www.iis.ee.ethz.ch/~neeri/macintosh/perl.html for many links to interesting MacPerl sites, and the applications/MPW tools, precompiled.

Perl5-Porters

The core development team have a mailing list for discussing fixes and changes to the language. Send mail to ``perl5-porters-request@perl.org'' with help in the body of the message for information on subscribing.

NTPerl

This list is used to discuss issues involving Win32 Perl 5 (Windows NT and Win95). Subscribe by mailing ListManager@ActiveWare.com with the message body:

    subscribe Perl-Win32-Users

The list software, also written in perl, will automatically determine your address, and subscribe you automatically. To unsubscribe, mail the following in the message body to the same address like so:

    unsubscribe Perl-Win32-Users

You can also check http://www.activeware.com/ and select ``Mailing Lists'' to join or leave this list.

Perl-Packrats

Discussion related to archiving of perl materials, particularly the Comprehensive Perl Archive Network (CPAN). Subscribe by emailing majordomo@cis.ufl.edu:

    subscribe perl-packrats

The list software, also written in perl, will automatically determine your address, and subscribe you automatically. To unsubscribe, simple prepend the same command with an ``un'', and mail to the same address like so:

    unsubscribe perl-packrats


Archives of comp.lang.perl.misc

Have you tried Deja News or Alta Vista?

ftp.cis.ufl.edu:/pub/perl/comp.lang.perl.*/monthly has an almost complete collection dating back to 12/89 (missing 08/91 through 12/93). They are kept as one large file for each month.

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 sense, Perl already is commercial software: It has a licence 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, dozens of software designers and developers, and thousands 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 wrong. 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.

Or you can purchase a real support contract. Although Cygnus historically provided this service, they no longer sell support contracts for Perl. Instead, the Paul Ingram Group will be taking up the slack through The Perl Clinic. The following is a commercial from them:

``Do you need professional support for Perl and/or Oraperl? Do you need a support contract with defined levels of service? Do you want to pay only for what you need?

``The Paul Ingram Group has provided quality software development and support services to some of the world's largest corporations for ten years. We are now offering the same quality support services for Perl at The Perl Clinic. This service is led by Tim Bunce, an active perl porter since 1994 and well known as the author and maintainer of the DBI, DBD::Oracle, and Oraperl modules and author/co-maintainer of The Perl 5 Module List. We also offer Oracle users support for Perl5 Oraperl and related modules (which Oracle is planning to ship as part of Oracle Web Server 3). 20% of the profit from our Perl support work will be donated to The Perl Institute.''

For more information, contact the The Perl Clinic:

    Tel:    +44 1483 424424
    Fax:    +44 1483 419419
    Web:    http://www.perl.co.uk/
    Email:  perl-support-info@perl.co.uk or Tim.Bunce@ig.co.uk

See also www.perl.com for updates on 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.com.

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.org? The Perl Institute?

The perl.com domain is managed by Tom Christiansen, who created it as a public service long before perl.org came about. Despite the name, it's a pretty non-commercial site meant to be a clearinghouse for information about all things Perlian, accepting no paid advertisements, bouncy happy gifs, or silly java applets on its pages. 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.

perl.org is the official vehicle for The Perl Institute. The motto of TPI is ``helping people help Perl help people'' (or something like that). It's a non-profit organization supporting development, documentation, and dissemination of perl.


How do I learn about object-oriented Perl programming?

the perltoot manpage (distributed with 5.004 or later) is a good place to start. Also, the perlobj manpage, the perlref manpage, and the perlmod manpage are useful references, while the perlbot manpage has some excellent tips and tricks.


AUTHOR AND COPYRIGHT

Copyright (c) 1997, 1998 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 Licence. 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 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.


DISCLAIMER

We are painfully aware that these documents may contain incorrect links and misformatted HTML. Such bugs lie in the automatic translation process that automatically created the hundreds and hundreds of separate documents that you find here. Please do not report link or formatting bugs, because we cannot fix per-document problems. The only bug reports that will help us are those that supply working patches to the installhtml or pod2html programs, or to the Pod::HTML module itself, for which I and the entire Perl community will shower you with thanks and praises.

If rather than formatting bugs, you encounter substantive content errors in these documents, such as mistakes in the explanations or code, please use the perlbug utility included with the Perl distribution.

--Tom Christiansen, Perl Documentation Compiler and Editor


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