MDK-ARM Keil, MDK-ARM Datasheet - Page 84

• Manufacturer Part Number: MDK-ARM
• Description: KIT REALVIEW MCU DEVELOPMENT
• Manufacturer: Keil
• Type: Compiler and IDEr

Specifications of MDK-ARM

• For Use With/related Products: ARM MCUs
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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Chapter 4. RL-TCPnet Introduction
This technique is very straightforward and easy to use. You can apply the CGI
scripting to any part of the HTML text, in order to generate dynamically any
form of HTML display. In the above example, we have only used one user
defined control character. It is possible to use multiple control characters to build
up complex dynamic pages.
Exercise: CGI Scripting
This exercise demonstrates the basic scripting method used to generate dynamic
HTML.
Data Input Using Web Forms
Now we will have a look at how to send data from the web browser to the C
application. There are two data input methods supported by the CGI module.
These two methods are called GET and POST. Both are used to input data
through a form.
The GET method should be used if the input data is idempotent. This means that
the input data has no observable effect on the world. For example, entering a
query into a search engine does not change any data held on the web.
The POST method should be used if the input data is going to be used to change
values “in the real world”. For example, if you are entering data into a database
you are changing the state of that database and should therefore use the POST
method. For our purpose of entering data into a small, embedded web server, we
will be using the POST method.
For our purposes, the GET method should be used to change environment
variables within the web server, while the POST method should be used to
transfer data between the user and the C application code.
Using the POST Method
To allow a remote user to enter data via a web browser, we need to add a form
cell and a submit button to our web page. The basic code for this is shown
below.