WWW server explanation (1)

WWW server explanation (1) -- Linux Enterprise Application-Linux server application information. The following is a detailed description. HTTP 1.1 protocol

When a web server was developed by a European Physical lab, the HTTP 1.0 communication protocol was used. The best supported browsers on the market were Netscape Navigator and Communicator, after the product became mature, Netscape launched the Gold version and began charging for the sale. In the Gold version, they proposed the concept of Online Editing web pages (after compilation, they should use FTP for uploading ), to implement this concept, we must develop new HTTP Communication Protocols. Of course, Netscape has not been removed from the market for a long time. We started to switch to Microsoft's IE and FrontPage. Microsoft is based on simple and easy-to-use considerations, actively participate in the formulation of the new version of HTTP communication protocol, which is what we will see later in HTTP 1.1.

The version of the HTTP 1.1 Communication Protocol has been greatly revised. For example, the file zip compression function is added and the MD5 encoding and BCC function is added ...... among them, the most important thing for Microsoft is that the PUT and DELETE commands of their proposals have been accepted, and the PUT commands are used to add webpages, modify webpage content, or change file names, the DELETE command is used to DELETE webpages or directories. Through this mechanism, you can easily use HTTP port 80 to directly update website content. This is the goal of Microsoft FrontPage Server Extension, currently, in addition to FrontPage support for PUT and DELETE commands, Winie developed by W3C can also be used to upload webpages (for Linux platforms, Apache mod_put is responsible for Server ). The following briefly describes the usage of each HTTP 1.1 command:

Command usage

OPTIONS queries or sets the URI flag. Through this mechanism, the server can negotiate with the browser about whether to compress or Cache data for transmission.

GET to obtain webpage information. You must use an absolute URL to request information. If you use a relative path, you must use the Host: header to indicate the destination URL, which is quite different from Version 1.0.

The HEAD is similar to GET, but only the webpage header is obtained, excluding the webpage internal text (except for the error)

Before using POST to obtain webpage information, upload the form information of the previous webpage. The difference between POST and GET is that the method for uploading materials is different. You can use GET to add information (? User = xxps & test = on...), but the quantity of information cannot exceed the limit of one row. In addition to using POST to upload forms (upload files), you can also:

Create comments for data sources on the Server

Provide materials to the Dynamic Data Link project (DataField) in the form)

Add data to the database (usually another webpage or text database)

This advanced form can be created on FrontPage, which is not described in detail here.

When the webpage specified by PUT does not exist, the webpage is automatically added. Otherwise, the webpage name must be replaced or changed.

DELETE deletes a specified webpage or empty directory

TRACE is used for loopback tracing at the application layer. It can be used with OPTIONS to specify Max-Forwards to determine the tracing depth. This command is used to track the passed Proxy (except for the error)

CONNECT is used by the Proxy server to establish an SSL channel. When a browser uses HTTPS to CONNECT to a webpage through the Proxy, an SSL channel must be established on the Proxy to provide services to the Client.

Understanding the meaning of the HTTP response status code (RFC 2068) is of great help in understanding the behavior and operation mechanism of the Apache server, and when the webpage is abnormal, the browser will also show these error messages, so that you can identify the cause of the problem by understanding these error messages. Therefore, this article lists the list of common status codes, as a supplementary teaching material, please read carefully.