CGI programs need to reside in a special directory so that Web servers know to execute the program rather than just display it to the browser. This directory is usually under direct control of the Webmaster, prohibiting the average user from creating CGI programs. There are other ways to allow access to CGI scripts, but the Webmaster must set these up. Perl (Practical Extraction and Report Language) is not a CGI-specific programming language. It is a powerful language with many applications far beyond the needs of CGI. Perl is one of the most common scripting languages used to write CGIs for Web sites. It is easy to use, and available for most platforms. Perl is an interpreted programming language with a number of features that make it very useful for manipulating textual data. As such, it is a good choice for a number of applications, including server gateways for HTTP servers. Perl's interesting features are: No need to explicitly declare variables. Instead, the first character of a variable reference distinguishes between scalar, array or associative array. No need to pre-declare the size of strings or of arrays. These start small and grow as large as necessary. All variables have predictable default values until explicitly set. A very rich set of pattern-matching operations that make it very easy to locate and process patterns of text. A complete set of arithmetic capabilities. A very complete set of built-in functions for a variety of tasks. A rather bizarre syntax that is sort of like 'C', but different in a number of ways. An orientation toward getting the job done quickly, rather than elegantly. Perl is interpreted, which means that no separate compilation step is explicitly necessary. Rather, one uses any text editor to prepare a text file containing the program source. The Perl processor then reads the whole file, converts it to an internal form and executes it immediately.PHP is a scripting language that is embedded in HTML ...
