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PERLFAQ1(1)                                Perl Programmers Reference Guide                               PERLFAQ1(1)



NAME
       perlfaq1 - General Questions About Perl

DESCRIPTION
       This section of the FAQ answers very general, high-level questions about Perl.

   What is Perl?
       Perl is a high-level programming language with an eclectic heritage written by Larry Wall and a cast of
       thousands.

       Perl's process, file, and text manipulation facilities make it particularly well-suited for tasks involving
       quick prototyping, system utilities, software tools, system management tasks, database access, graphical
       programming, networking, and web programming.

       Perl derives from the ubiquitous C programming language and to a lesser extent from sed, awk, the Unix shell,
       and many other tools and languages.

       These strengths make it especially popular with web developers and system administrators. Mathematicians,
       geneticists, journalists, managers and many other people also use Perl.

   Who supports Perl? Who develops it? Why is it free?
       The original culture of the pre-populist Internet and the deeply-held beliefs of Perl's author, Larry Wall,
       gave rise to the free and open distribution policy of Perl. Perl is supported by its users. The core, the
       standard Perl library, the optional modules, and the documentation you're reading now were all written by
       volunteers.

       The core development team (known as the Perl Porters) are a group of highly altruistic individuals committed
       to producing better software for free than you could hope to purchase for money. You may snoop on pending
       developments via the archives <http://www.nntp.perl.org/group/perl.perl5.porters/> or read the faq
       <http://dev.perl.org/perl5/docs/p5p-faq.html>, or you can subscribe to the mailing list by sending
       [email protected] a subscription request (an empty message with no subject is fine).

       While the GNU project includes Perl in its distributions, there's no such thing as "GNU Perl". Perl is not
       produced nor maintained by the Free Software Foundation. Perl's licensing terms are also more open than GNU
       software's tend to be.

       You can get commercial support of Perl if you wish, although for most users the informal support will more
       than suffice. See the answer to "Where can I buy a commercial version of Perl?" for more information.

   Which version of Perl should I use?
       (contributed by brian d foy)

       There is often a matter of opinion and taste, and there isn't any one answer that fits everyone. In general,
       you want to use either the current stable release, or the stable release immediately prior to that one.
       Currently, those are perl5.14.x and perl5.12.x, respectively.

       Beyond that, you have to consider several things and decide which is best for you.

       ·   If things aren't broken, upgrading perl may break them (or at least issue new warnings).

       ·   The latest versions of perl have more bug fixes.

       ·   The Perl community is geared toward supporting the most recent releases, so you'll have an easier time
           finding help for those.

       ·   Versions prior to perl5.004 had serious security problems with buffer overflows, and in some cases have
       ·   The current leading implementation of Perl 6, Rakudo, released a "useful, usable, 'early adopter'"
           distribution of Perl 6 (called Rakudo Star) in July of 2010. Please see <http://rakudo.org/> for more
           information.

       ·   There are really two tracks of perl development: a maintenance version and an experimental version. The
           maintenance versions are stable, and have an even number as the minor release (i.e. perl5.10.x, where 10
           is the minor release). The experimental versions may include features that don't make it into the stable
           versions, and have an odd number as the minor release (i.e. perl5.9.x, where 9 is the minor release).

   What are Perl 4, Perl 5, or Perl 6?
       In short, Perl 4 is the parent to both Perl 5 and Perl 6. Perl 5 is the older sibling, and though they are
       different languages, someone who knows one will spot many similarities in the other.

       The number after Perl (i.e. the 5 after Perl 5) is the major release of the perl interpreter as well as the
       version of the language. Each major version has significant differences that earlier versions cannot support.

       The current major release of Perl is Perl 5, first released in 1994. It can run scripts from the previous
       major release, Perl 4 (March 1991), but has significant differences.

       Perl 6 is a reinvention of Perl, it is a language in the same lineage but not compatible. The two are
       complementary, not mutually exclusive. Perl 6 is not meant to replace Perl 5, and vice versa. See "What is
       Perl 6?" below to find out more.

       See perlhist for a history of Perl revisions.

   What is Perl 6?
       Perl 6 was originally described as the community's rewrite of Perl 5.  Development started in 2002; syntax and
       design work continue to this day.  As the language has evolved, it has become clear that it is a separate
       language, incompatible with Perl 5 but in the same language family.

       Contrary to popular belief, Perl 6 and Perl 5 peacefully coexist with one another. Perl 6 has proven to be a
       fascinating source of ideas for those using Perl 5 (the Moose object system is a well-known example). There is
       overlap in the communities, and this overlap fosters the tradition of sharing and borrowing that have been
       instrumental to Perl's success. The current leading implementation of Perl 6 is Rakudo, and you can learn more
       about it at <http://rakudo.org>.

       If you want to learn more about Perl 6, or have a desire to help in the crusade to make Perl a better place
       then read the Perl 6 developers page at <http://www.perl6.org/> and get involved.

       "We're really serious about reinventing everything that needs reinventing."  --Larry Wall

   How stable is Perl?
       Production releases, which incorporate bug fixes and new functionality, are widely tested before release.
       Since the 5.000 release, we have averaged about one production release per year.

       The Perl development team occasionally make changes to the internal core of the language, but all possible
       efforts are made toward backward compatibility.

   Is Perl difficult to learn?
       No, Perl is easy to start learning <http://learn.perl.org/> --and easy to keep learning. It looks like most
       programming languages you're likely to have experience with, so if you've ever written a C program, an awk
       script, a shell script, or even a BASIC program, you're already partway there.

       Most tasks only require a small subset of the Perl language. One of the guiding mottos for Perl development is

   How does Perl compare with other languages like Java, Python, REXX, Scheme, or Tcl?
       Perl can be used for almost any coding problem, even ones which require integrating specialist C code for
       extra speed. As with any tool it can be used well or badly. Perl has many strengths, and a few weaknesses,
       precisely which areas are good and bad is often a personal choice.

       When choosing a language you should also be influenced by the resources <http://www.cpan.org/>, testing
       culture <http://www.cpantesters.org/> and community <http://www.perl.org/community.html> which surrounds it.

       For comparisons to a specific language it is often best to create a small project in both languages and
       compare the results, make sure to use all the resources <http://www.cpan.org/> of each language, as a language
       is far more than just it's syntax.

   Can I do [task] in Perl?
       Perl is flexible and extensible enough for you to use on virtually any task, from one-line file-processing
       tasks to large, elaborate systems.

       For many people, Perl serves as a great replacement for shell scripting.  For others, it serves as a
       convenient, high-level replacement for most of what they'd program in low-level languages like C or C++. It's
       ultimately up to you (and possibly your management) which tasks you'll use Perl for and which you won't.

       If you have a library that provides an API, you can make any component of it available as just another Perl
       function or variable using a Perl extension written in C or C++ and dynamically linked into your main perl
       interpreter. You can also go the other direction, and write your main program in C or C++, and then link in
       some Perl code on the fly, to create a powerful application. See perlembed.

       That said, there will always be small, focused, special-purpose languages dedicated to a specific problem
       domain that are simply more convenient for certain kinds of problems. Perl tries to be all things to all
       people, but nothing special to anyone. Examples of specialized languages that come to mind include prolog and
       matlab.

   When shouldn't I program in Perl?
       One good reason is when you already have an existing application written in another language that's all done
       (and done well), or you have an application language specifically designed for a certain task (e.g. prolog,
       make).

       If you find that you need to speed up a specific part of a Perl application (not something you often need) you
       may want to use C, but you can access this from your Perl code with perlxs.

   What's the difference between "perl" and "Perl"?
       "Perl" is the name of the language. Only the "P" is capitalized.  The name of the interpreter (the program
       which runs the Perl script) is "perl" with a lowercase "p".

       You may or may not choose to follow this usage. But never write "PERL", because perl is not an acronym.

   What is a JAPH?
       (contributed by brian d foy)

       JAPH stands for "Just another Perl hacker,", which Randal Schwartz used to sign email and usenet messages
       starting in the late 1980s. He previously used the phrase with many subjects ("Just another x hacker,"), so to
       distinguish his JAPH, he started to write them as Perl programs:

           print "Just another Perl hacker,";


       In general, the benefit of a language is closely related to the skill of the people using that language. If
       you or your team can be faster, better, and stronger through Perl, you'll deliver more value. Remember, people
       often respond better to what they get out of it. If you run into resistance, figure out what those people get
       out of the other choice and how Perl might satisfy that requirement.

       You don't have to worry about finding or paying for Perl; it's freely available and several popular operating
       systems come with Perl. Community support in places such as Perlmonks ( <http://www.perlmonks.com> ) and the
       various Perl mailing lists ( <http://lists.perl.org> ) means that you can usually get quick answers to your
       problems.

       Finally, keep in mind that Perl might not be the right tool for every job. You're a much better advocate if
       your claims are reasonable and grounded in reality. Dogmatically advocating anything tends to make people
       discount your message. Be honest about possible disadvantages to your choice of Perl since any choice has
       trade-offs.

       You might find these links useful:

       ·   <http://www.perl.org/about.html>

       ·   <http://perltraining.com.au/whyperl.html>

AUTHOR AND COPYRIGHT
       Copyright (c) 1997-2010 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.



perl v5.16.3                                          2013-03-04                                          PERLFAQ1(1)