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 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 other 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).

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://language.perl.com/info/software.html
    http://www.perl.com/pub/language/info/software.html#binary
    http://www.perl.com/CPAN/ports/

Someone looking for a Perl for Win16 might look to Laszlo Molnar's djgpp port in http://www.perl.com/CPAN/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 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 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 the perlfaq8 reference page.

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 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.

Tutorial documents are included in current or upcoming Perl releases include perltoot for objects, perlopentut for file opening semantics, perlreftut for managing references, and perlxstut 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://language.perl.com/info/documentation.html
    http://reference.perl.com/query.cgi?tutorials

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 AltaVista (http://www.altavista.com), Deja (http://www.deja.com), 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"):
	by 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"):
	by 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"):
	by 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 mostly 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

    *Perl in a Nutshell
        by Ellen Siever, Stephan Spainhour, and Nathan Patwardhan

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

    *Learning Perl/Tk
        by Nancy Walsh

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-local
  http://www.perl.com/CPAN	(redirects to an ftp mirror)
  ftp://cpan.valueclick.com/pub/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 Perl Mongers attempt to maintain a list of mailing lists at:

	http://www.perl.org/support/online_support.html#mail

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'll probably 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 carry a Perl distribution on them, 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.

Or 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.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 Mongers? pm.org? perl.org?

The perl.com domain is owned 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. 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. For details, see the Perl Mongers web site at http://www.perlmongers.org/.

Perl Mongers uses the pm.org domain for services related to Perl user groups. 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 maintains 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://history.perl.org/
    http://bugs.perl.org/
    http://www.news.perl.org/

AUTHOR AND COPYRIGHT

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 perlfaq.

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.

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perlfaq2
Obtaining and Learning about Perl

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