=head1 NAME
-perlfaq1 - General Questions About Perl ($Revision: 7997 $)
+perlfaq1 - General Questions About Perl
=head1 DESCRIPTION
(contributed by brian d foy)
There is often a matter of opinion and taste, and there isn't any one
-answer that fits anyone. In general, you want to use either the current
+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 perl5.8.x and perl5.6.x, respectively.
+Currently, those are perl5.10.x and perl5.8.x, respectively.
Beyond that, you have to consider several things and decide which is best
for you.
=item *
-The immediate, previous releases (i.e. perl5.6.x ) are usually maintained
+The immediate, previous releases (i.e. perl5.8.x ) are usually maintained
for a while, although not at the same level as the current releases.
=item *
-No one is actively supporting perl4.x. Five years ago it was a dead
+No one is actively supporting Perl 4. Five years ago it was a dead
camel carcass (according to this document). Now it's barely a skeleton
as its whitewashed bones have fractured or eroded.
=item *
-There is no perl6.x for the next couple of years. Stay tuned, but don't
-worry that you'll have to change major versions of Perl soon (i.e. before
-2008).
+There is no Perl 6 release scheduled, but it will be available when
+it's ready. Stay tuned, but don't worry that you'll have to change
+major versions of Perl; no one is going to take Perl 5 away from you.
=item *
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. perl5.8.x, where 8 is the
+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).
=back
-=head2 What are perl4, perl5, or perl6?
+=head2 What are Perl 4, Perl 5, or Perl 6?
(contributed by brian d foy)
-In short, perl4 is the past, perl5 is the present, and perl6 is the
+In short, Perl 4 is the past, Perl 5 is the present, and Perl 6 is the
future.
-The number after perl (i.e. the 5 after perl5) is the major release
+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 perl5, and was released in 1994.
-It can run scripts from the previous major release, perl4 (March 1991),
+The current major release of Perl is Perl 5, and was released in 1994.
+It can run scripts from the previous major release, Perl 4 (March 1991),
but has significant differences. It introduced the concept of references,
-complex data structures, and modules. The perl5 interpreter was a
+complex data structures, and modules. The Perl 5 interpreter was a
complete re-write of the previous perl sources.
-Perl6 is the next major version of Perl, but it's still in development
+Perl 6 is the next major version of Perl, but it's still in development
in both its syntax and design. The work started in 2002 and is still
ongoing. Many of the most interesting features have shown up in the
-latest versions of perl5, and some perl5 modules allow you to use some
-perl6 syntax in your programs. You can learn more about perl6 at
+latest versions of Perl 5, and some Perl 5 modules allow you to use some
+Perl 6 syntax in your programs. You can learn more about Perl 6 at
http://dev.perl.org/perl6/ .
See L<perlhist> for a history of Perl revisions.
Ponie stands for "Perl On the New Internal Engine", started by Arthur
Bergman from Fotango in 2003, and subsequently run as a project of The
Perl Foundation. It was abandoned in 2006
-U<http://www.nntp.perl.org/group/perl.ponie.dev/487> .
+( http://www.nntp.perl.org/group/perl.ponie.dev/487 ).
Instead of using the current Perl internals, Ponie aimed to create a
new one that would provide a translation path from Perl 5 to Perl 6
able to just keep using Perl 5 with Parrot, the virtual machine which
will compile and run Perl 6 bytecode.
-=head2 What is perl6?
+=head2 What is Perl 6?
At The Second O'Reilly Open Source Software Convention, Larry Wall
-announced Perl6 development would begin in earnest. Perl6 was an oft
+announced Perl 6 development would begin in earnest. Perl 6 was an oft
used term for Chip Salzenberg's project to rewrite Perl in C++ named
Topaz. However, Topaz provided valuable insights to the next version
of Perl and its implementation, but was ultimately abandoned.
-If you want to learn more about Perl6, or have a desire to help in
-the crusade to make Perl a better place then peruse the Perl6 developers
+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 peruse the Perl 6 developers
page at http://dev.perl.org/perl6/ and get involved.
-Perl6 is not scheduled for release yet, and Perl5 will still be supported
-for quite awhile after its release. Do not wait for Perl6 to do whatever
+Perl 6 is not scheduled for release yet, and Perl 5 will still be supported
+for quite awhile after its release. Do not wait for Perl 6 to do whatever
you need to do.
"We're really serious about reinventing everything that needs reinventing."
Larry and the Perl development team occasionally make changes to the
internal core of the language, but all possible efforts are made toward
-backward compatibility. While not quite all perl4 scripts run flawlessly
-under perl5, an update to perl should nearly never invalidate a program
+backward compatibility. While not quite all Perl 4 scripts run flawlessly
+under Perl 5, an update to perl should nearly never invalidate a program
written for an earlier version of perl (barring accidental bug fixes
and the rare new keyword).
of programming experience, an understanding of regular expressions, and
the ability to understand other people's code. If there's something you
need to do, then it's probably already been done, and a working example is
-usually available for free. Don't forget the new perl modules, either.
+usually available for free. Don't forget Perl modules, either.
They're discussed in Part 3 of this FAQ, along with CPAN, which is
discussed in Part 2.
=head2 What's the difference between "perl" and "Perl"?
One bit. Oh, you weren't talking ASCII? :-) Larry now uses "Perl" to
-signify the language proper and "perl" the implementation of it,
-i.e. the current interpreter. Hence Tom's quip that "Nothing but perl
-can parse Perl." You may or may not choose to follow this usage. For
-example, parallelism means "awk and perl" and "Python and Perl" look
-OK, while "awk and Perl" and "Python and perl" do not. But never
-write "PERL", because perl is not an acronym, apocryphal
-folklore and post-facto expansions notwithstanding.
+signify the language proper and "perl" the implementation of it, i.e.
+the current interpreter. Hence Tom's quip that "Nothing but perl can
+parse Perl."
+
+Before the first edition of I<Programming perl>, people commonly
+referred to the language as "perl", and its name appeared that way in
+the title because it referred to the interpreter. In the book, Randal
+Schwartz capitalised the language's name to make it stand out better
+when typeset. This convention was adopted by the community, and the
+second edition became I<Programming Perl>, using the capitalized
+version of the name to refer to the language.
+
+You may or may not choose to follow this usage. For example,
+parallelism means "awk and perl" and "Python and Perl" look good, while
+"awk and Perl" and "Python and perl" do not. But never write "PERL",
+because perl is not an acronym, apocryphal folklore and post-facto
+expansions notwithstanding.
=head2 Is it a Perl program or a Perl script?
print "Just another Perl hacker,";
-Note the trailing comma and space, which allows the addition of other
-JAxH clauses for his many other interests.
-
Other people picked up on this and started to write clever or obfuscated
programs to produce the same output, spinning things quickly out of
control while still providing hours of amusement for their creators and
=back
-=head1 REVISION
-
-Revision: $Revision: 7997 $
-
-Date: $Date: 2006-11-01 09:29:17 +0100 (mer, 01 nov 2006) $
-
-See L<perlfaq> for source control details and availability.
-
=head1 AUTHOR AND COPYRIGHT
-Copyright (c) 1997-2006 Tom Christiansen, Nathan Torkington, and
+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
https://perl5.git.perl.org / perl5.git / blobdiff