B.2 Versions of Perl
Perl,
like almost all popular software, has gone through much growth and
change over the course of its 15-year life. The authors, Larry Wall
and a large group of cohorts, publish new versions periodically.
These new versions have been carefully designed to support most
programs written under old versions, but occasionally some major new
features are added that simply won't work with older
versions of Perl. This book assumes you have Perl Version 5 or higher installed.
It's likely that if you have Perl already installed
on your computer, it's Perl 5. But
it's best to check. On a Unix or Linux system, or
from an MS-DOS or Mac OS X command window, the
perl -v command just shown
displays the version number, in my case Version 5.8.0. The number
5.8.0 is "bigger" than 5, so
I'm okay. If you get a smaller number (very likely
4.036), you'll have to install a recent version of
Perl to enable the majority of programs in this book to run as shown. What about future versions? Perl is always evolving, and Perl Version
6 is on the horizon. Will the code in this book still work in Perl 6?
The answer is yes. Although Perl 6 is going to add some new things to
the language, it should have no trouble with the Perl 5 code in this
book. |