Welcome to ITM Web100 Training Program

Environment Variables

• So, what do we have so far?
  1. First you write an HTML page with a FORM in it.

  2. Some user retrieves your HTML page using a web browser

  3. The web browser interprets the HTML and presents the Form to the user as a set of input widgets.

  4. The user inputs some data into the widgets and then clicks on a submit button

  5. The browser then goes through each of the input widgets and collects the information that the user has input and creates the body of the HTTP call it is going to send to the server referenced in the FORM ACTION attribute.

  6. Then the browser contacts the server using the method defined by the FORM tag's METHOD attribute and hands off the data.

• So what does the server do with the data?

• Typically, the server will hand the request off to some CGI script that has been specified in the ACTION attribute in the FORM tag that made the request

• So the server must execute the CGI script and feed it the data received from the web browser.

• To do so, the server creates an associative array that will be used to hold all of the data needed by the script. The array is called %ENV .