Tài liệu Web Client Programming with Perl-Chapter 3: Learning HTTP- P2 pdf

... from URL-encoded format to retrieve the values entered by the user. File uploads with POST Chapter 3: Learning HTTP- P1 In the previous chapter, we went through a few examples of HTTP transactions ... that it seemed best to present it this way. Client Request Methods A client request method is a "command" or "request" that a web client issues to a se...

Ngày tải lên: 26/01/2014, 07:20

... data with PUT. In practice, a web server may request authorization from the client. Most webmasters won't allow any arbitrary client to publish documents on the server. When prompted with ... post office is nice enough to forward your mail to Chapter 3: Learning HTTP- P2 PUT: Store the Entity-Body at the URL When a client uses the PUT method, it requests that...

Ngày tải lên: 26/01/2014, 07:20

... Graphical Examples with Perl/Tk- P4 Check if Servers Are up: webping For the last example, we'll build a GUI interface that will allow us to check and see if several web sites are running, ... similar to the UNIX ping command, we call it webping. This application would be useful to a web administrator who had to keep track of many different web sites, and wanted to know wh...

Ngày tải lên: 14/12/2013, 13:15

... Browser-P1 Before you start writing your own web programs, you have to become comfortable with the fact that your web browser is just another client. Lots of complex things are happening: ... rendering. But all of that is gravy; without actually negotiating with web servers and retrieving documents via HTTP, the browser would be as useless as a TV without a tuner. HTTP may s...

Ngày tải lên: 26/01/2014, 07:20

... structure of a client request. Figure 2-10. Structure of a client request HTTP transactions do not need to use all the headers. In fact, it is possible to perform some HTTP requests without supplying ... GET / HTTP/1.0 with an empty header is sufficient for most servers to understand the client. HTTP requests have the following general components: 1. The first line tells the...

Ngày tải lên: 26/01/2014, 07:20

... 1:Introduction- Web Client Programming with Perl So what does Web client programming mean, and what do you need to learn to do it? A web client is an application that communicates with a web server, ... 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 w...

Ngày tải lên: 26/01/2014, 07:20

... web client requests the document without sending an Authorization header. If the server denies access to the document, the server specifies the authorization method for the client to use with ... header. Clients use this information to correctly handle the media type and format of the entity- body. A client might also use a Content-type header with the POST or PUT method. Mo...

Ngày tải lên: 17/10/2013, 19:15

... not fully 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 ... character is '^'. Tue Jun 14 00: 03:1 2 1996 Connection closed by foreign host. Your First Web Client Let's modify the previous code to work with a web serve...

Ngày tải lên: 20/10/2013, 10:15

... your client. In the event of a redirection, will your client handle it? Does it examine the Location header? The answers to these questions depend on the purpose of the client. Does the client ... Socket; # include Socket module require 'tcp.pl'; # file with Open_TCP routine require &apos ;web. pl'; # file with parseURL routine use vars qw($opt_h $opt_i $opt_...

Ngày tải lên: 20/10/2013, 10:15

... that 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, ... module describes client requests, server responses, and dates, and computes a client/ server negotiation.  The LWP module is the core of all web client programs. It allows the...

Ngày tải lên: 24/10/2013, 08:15