What Is CGI Scripting Explain With Example?

CGI (Common Gateway Interface) scripting is a powerful tool that allows websites to interact with users and perform dynamic actions. In simple terms, it is a way for web servers to generate dynamic web pages by executing scripts on the server side. These scripts can be written in various programming languages such as Perl, Python, or even shell scripting languages like Bash.

How Does CGI Scripting Work?

When a user interacts with a website, their actions trigger an HTTP request that is sent to the web server. The server then processes this request and determines if it needs to execute a CGI script. If it does, the server passes control to the CGI script, which generates dynamic content based on the user’s request.

To better understand how CGI scripting works, let’s consider an example:

Example: A Simple CGI Script

Suppose we have a website that asks users for their name and then greets them with a personalized message.

Step 1: Create an HTML form using the <form> tag:

<form method="POST" action="greeting.cgi">
  <label for="name">Enter your name:</label>
  <input type="text" name="name" id="name">
  <input type="submit" value="Submit">
</form>

Step 2: Create the CGI script file (in this case, greeting.cgi) and write the necessary code to handle the form submission:

#!/usr/bin/perl

use strict;
use warnings;

print "Content-Type: text/html\n\n";

my $name = $ENV{'QUERY_STRING'};
$name =~ s/name=//;

print "<h2>Hello, $name!</h2>";

Step 3: Make the CGI script executable and place it in the appropriate directory on the server.

When a user visits the website and submits their name through the form, the web server executes the greeting.cgi script. The script retrieves the user’s name from the HTTP request, generates an HTML page with a personalized greeting, and sends it back to the user’s browser for display.

Advantages of CGI Scripting

CGI scripting offers several advantages:

• Dynamic Content: CGI scripts allow websites to generate dynamic content based on user input or other factors. This enables interactive features like feedback forms, search functionality, and personalized greetings.
• Language Flexibility: CGI supports a wide range of programming languages, giving developers the flexibility to choose a language they are comfortable with or one that best suits their project requirements.
• Data Processing: CGI scripts can process and manipulate data submitted through forms or retrieve information from databases. This allows for data validation, calculations, and custom data handling.

Conclusion

In summary, CGI scripting is an essential tool for creating dynamic websites that can interact with users and perform various tasks. By executing scripts on the server side, web servers can generate dynamic content based on user input or other factors. With its flexibility and ability to process data, CGI scripting opens up endless possibilities for creating interactive web applications.