CGI Scripts

Language Choice

CGI Caveats | Language Choice | CGI and Forms

The warnings of the previous section were meant to discourage the faint of heart. We certainly did not mean to imply that writing and implementing CGI scripts are beyond ordinary mortals, only that they are beyond the average difficulty level of the present Tutorial. For those who may want to go further, we provide some additional information that will get you started in the right direction.

What Languages Are Used for CGI Scripts?

If you decide that you wish to implement CGI scripts of your own creation, you then need to decide which language you will want to use for writing the scripts. In principle, you can use any language that allows you to create executable code on the server to accomplish the required task. The earlier example that returned the current date and time used what is called a Unix shell script, which is a rather simple scripting language available on Unix servers (If you are interested, here is a listing of the shell script that returned the date.)

In practice, the server software on some platforms may limit you in your choice of languages. For instance, the MacHTTP Web server for the Macintosh will only execute programs written in the Mac's proprietary scripting language called AppleScript.

Perl and C

At present two of the most commonly used languages for writing gateway programs (especially on Unix systems, which are the most common servers on the Web) are C and Perl (which then allows you to write "Perly gateway scripts"!). Both of these languages are quite powerful and well suited for CGI programming, but they require more time to learn than HTML. Perl is probably the easier to pick up: much of Perl's command syntax is "C-like", but the Perl command set is smaller and is geared more toward the sort of text manipulation that is often required in CGI programs.

In addition, Perl is technically an interpreted language, while C is a compiled language. On the one hand this means that a C program will probably execute faster than a Perl program designed to perform the same task; on the other hand, a Perl program is generally easier for a novice to debug since you don't have to deal with the compilation process after each modification of the code.

Speed vs. Ease of Use

Your choice of programming languages should not be based solely on the ease of a language to learn, however. You should also think carefully about the sort of tasks you are likely to want your CGI programs to perform. As noted, Perl is very well suited for text manipulations and related tasks, but C would probably be preferred for a program that needs to do a good deal of "number crunching". For most Web applications number crunching is not very important (unless you are into heavy-duty scientific applications, for example) and speed is not an over-riding issue.