Tài liệu Web Client Programming with Perl-Chapter 2: Demystifying the Browser-P2 doc

... The fourth line (Content-type) tells the browser the type of the document. In this case, it is HTML. 5. The fifth line tells the client how many bytes are in the entity body that follows the ... engine. Chapter 2: Demystifying the Browser-P1 Before you start writing your own web programs, you have to become comfortable with the fact that your web browser...

Ngày tải lên: 26/01/2014, 07:20

... headers tell the server more information about the client. The client can identify itself and the user to the server, and specify preferred document formats that it would like to see from the server. ... server response In the server response, the general header and entity headers are the same as those used in the client request. The entity-body is like the...

Ngày tải lên: 26/01/2014, 07:20

... our source code are the functions that we've bound to the buttons and various actions in the GUI. Remember, this is where the real work comes in; without these functions the GUI would just ... would be nice for the program to remember them, and bring them up automatically the next time we start the program. Here's the final code, with most of the mentioned...

Ngày tải lên: 14/12/2013, 13:15

... entity-body. The headers returned by the server with the HEAD method should be exactly the same as the headers returned with a GET request. This method is often used by web clients to verify the document's ... protocol, in which the client makes a request, the server responds, and the transaction is then finished. The client initiates the transaction a...

Ngày tải lên: 26/01/2014, 07:20

... image/jpeg The proxy then examines the URL, contacts www.ora.com, forwards the client& apos;s request, and then returns the response from the server to the original client. When forwarding the request ... a document has moved, the server might be configured to tell clients where it has been moved to. Clients can then retrieve the new URL silently, without the user know...

Ngày tải lên: 26/01/2014, 07:20

... compliant with the HTTP specs, the web server won't understand you! Perhaps your web client works with one web server but not another. Or maybe your web client works most of the time, ... assign the socket to a particular port on the host. The server then uses the listen( ) and accept( ) routines to establish communication on that port. On the other e...

Ngày tải lên: 20/10/2013, 10:15

... example, if the URL used by the client becomes obsolete or is changed, the client may interpret the entity- body incorrectly. Media types for the URL may change, and could be noticed in the HTTP ... not at the location specified by your client. In the event of a redirection, will your client handle it? Does it examine the Location header? The answers to these q...

Ngày tải lên: 20/10/2013, 10:15

... are useful for client programming. The LWP Module The LWP module, in the context of web clients, performs client requests over the network. There are 10 classes in all within the LWP module, ... a client/ server negotiation.  The LWP module is the core of all web client programs. It allows the client to communicate over the network with the server.  T...

Ngày tải lên: 24/10/2013, 08:15

... invoked with no parameters, this returns the default port for the URL defined in the object. The default port is based on the scheme used. Even if the port for the URL is explicitly changed by the ... Since we're programming a web robot, the name of the robot and the email address of the user are mandatory. So, we pass that information to the LWP::RobotU...

Ngày tải lên: 24/10/2013, 08:15

... documents to web browsers without being limited to the functionality of an existing web server. HTTP programming takes you out of the realm of the everyday web user and into the world of the ... new page appeared. Clients and Servers Your web browser is an example of a web client. The remote machine containing the document you requested is called a web server...

Ngày tải lên: 26/01/2014, 07:20