HTTP Protocol : The Request

An HTTP request includes:

- A request line

this line specifies the requested document, the method and the protocol version which are used. This three elements must be separated by a space.

- The request header fields

This fields are optional. They allow to send more information about the request or the client. (Navigator, OS...).

Header name	Description
Accept	Content accepted by the browser (example : text/html).
Accept-Charset	Charset accepted by the browser
Accept-Encoding	Data encoding accepted by the browser
Accept-Language	Language accepted by the browser
Authorization	Identification of the user to the server
Content-Encoding	Encoding type of the request body
Content-Language	Language of the request body
Content-Length	Length of the request body
Content-Type	Content-Type of the request body (example : text/html)
Date	Date of the beginning to the data transfer
Forwarded	Used by intermediate machines between browser and server
From	allow to specify the client e-mail
Link	link between two URLs
Orig-URL	Original URL of the request
User-Agent	Client informations about name and version of the navigator and the OS.

- The body request

Optional lines which allow to send data with, for example, the POST method.

To summarize, this is the form of an HTTP request :

METHOD URL VERSION
HEADER : Value
EMPTY LINE
REQUEST BODY

And here is an example of an HTTP request :

GET http://www.eaeeie.org HTTP/1.1
Accept : text/html
User-Agent : Mozilla/4.0 (compatible; MSIE 5.0; Windows 95)
Empty line