Apache: The Definitive Guide, 3rd Edition

Perl

Perl, on the other hand, is an effective but annoyingly idiosyncratic language that has not been designed along sound theoretical lines. However, it has been around since 1987, has had many tiresome features ironed out of it, and has accumulated an enormous body of enthusiasts and supporting software in the CPAN archive. Its star feature is its regular expression tool for parsing lines of text. When one is programming for the Web, this is constantly in use to dissect URLs and strip meaning out of the returns from HTML forms. Perl also has a construct called an “associative array,” which gives names to the array elements. This can be very useful, but its syntax can also be very complicated and mind-bending.

Perhaps the most serious defect of Perl is its absence of variable declaration. You can make up variable names on the fly (usually by mistyping or misthinking): Perl will create them and reference them, even if they are wrong and should not exist. This problem can be mitigated, however, with the use of the -w command line flag, as well as the following:

use strict;

within the scripts.

Anyone who writes Perl needs the “Camel Book”^[1] from O’Reilly & Associates. For all its occasional jokes, this is a fairly heavyweight book that is not meant to guide novices’ first steps. Sriram Srinivasan’s Advanced Perl Programming (O’Reilly, 1997) is also useful. If you are a complete newcomer to programming (and we all were once) you might like to look at Perl for Web Site Management by ...