Another approach to the problem of orchestrating HTML with CGI scripts, databases, and Apache is PHP. Someone who is completely new to programming of any sort might do best to start with PHP, which extends HTML — and one has to learn HTML anyway.
Instead of writing CGI scripts in a language like Perl or Java, which then run in interaction with Apache and generate HTML pages to be sent to the client, PHP’s strategy is to embed itself into the HTML. The author then writes HTML with embedded commands, which are interpreted by the PHP package as the page is served up. For instance, you could include the line:
Hello world!<BR>
in your HTML. Or, you could have the PHP statement:
<?php print "Hello world!<BR>";?>
which would produce exactly the same effect. The <? php
...?> construction embeds PHP commands within standard
HTML. PHP has resources to interact with databases and do most things
that other scripting languages do.
The syntax of PHP is based on that of C with bits of Perl. The main problem with learning a new programming language is unlearning irrelevant bits of the ones you already know. So if you have no programming experience to confuse you, PHP may be as good a place to start as any. Its promoters claim that over a million web sites use it, so you will not be the first.
Also, since it was designed for its web function from the start, it avoids a lot of the bodging that has proven necessary to get Perl to work properly in a web environment. On the other hand, it is relatively new and has not accumulated the wealth of prewritten modules that fill the Comprehensive Perl Archive Network (CPAN) library (see http://www.cpan.org).
For example, one of us (PL) was creating a web site that offered a full-text search on a medical encyclopedia. The problem with text searching is that the visitor looks for “operation,” but the text talks about “operated on,” “operating theater,” etc. The answer is to work back to the word stem, and there are several Perl modules in CPAN that strip the endings from English words to get, for instance, the stem “operat” from “operation,” the word the enquirer entered. If one wanted to go further and parse English sentences into their parts of speech, modules to do that exist as well. But they might not exist for PHP and it might be hard to create them on your own. An early decision to take the simple route might prove expensive later on.
PHP installation is covered in Chapter 15.