Last updated: July 20, 2019
CGI scripts can be written in virtually any language, although scripting languages are among the more popular choices.
The Perl programming language is known for being the “duct-tape of the Internet.” It excels at text manipulation and database access. Well-established Web frameworks and the ability to embed it into Web servers make it a popular choice for CGI scripts.
PHP is another scripting language that is commonly used for Web-based programming. Its flexible nature makes it ideal for use in creating CGI scripts. In fact, PHP started its life when its creator, Rasmus Lerdorf, wrote a number of CGI scripts in the C language. As he continued to add features, his work eventually evolved into PHP.
Tcl, Python and Ruby are also commonly used.
As Internet technologies have evolved and advanced, more complex alternatives to CGI have gained in popularity. In particular, using PHP, Python, Ruby on Rails, Java or ASP to write complete Web applications that can duplicate, and go far beyond, the functionality of CGI scripts is a viable alternative.
Advantages of CGI
In spite of the rise of alternatives, CGI still has some inherent advantages. The fact that scripts can be created in virtually any language contributes to its ongoing popularity.
Its long history and wide use have also contributed to a plethora of pre-written scripts being available on the Internet. Many of these scripts, such as ones to submit an email form, can be easily edited and used, even by relative novices.
CGI scripts are not without disadvantages, especially as it relates to the performance of a server. Poorly written scripts can get caught in endless loops, eating up system resources.
CGI scripts suffer from scalability limitations as well. Because the server has to spawn a new process each time a script is called, websites that process many requests in a short period of time can quickly be overwhelmed or slowed to a crawl.
For these reasons, many developers choose more robust alternatives for anything but the most basic application.
Points to Remember
CGI continues to be a viable way of submitting information and generating dynamic content by providing a method for a Web browser to run an executable script.
While CGi is simple-to-use, there are many alternatives that provide superior capabilities and performance.