0 Óˆ¿á 0¾ß Õˆ¿á 0¾ß ׈¿á 0¾ß Ùˆ¿á 0¾ß Ûˆ¿á 0¾ß ݈¿á 0¾ß0߈l–Ðz¾”TÐ;Ê‚ ÆY¸”ţ⠄\mÏ_‹uÐb &=LV[(Àá?÷ßpackage LWP; $VERSION = "6.05"; sub Version { $VERSION; } require 5.008; require LWP::UserAgent; # this should load everything you need 1; __END__ =encoding utf-8 =head1 NAME LWP - The World-Wide Web library for Perl =head1 SYNOPSIS use LWP; print "This is libwww-perl-$LWP::VERSION\n"; =head1 DESCRIPTION The libwww-perl collection is a set of Perl modules which provides a simple and consistent application programming interface (API) to the World-Wide Web. The main focus of the library is to provide classes and functions that allow you to write WWW clients. The library also contain modules that are of more general use and even classes that help you implement simple HTTP servers. Most modules in this library provide an object oriented API. The user agent, requests sent and responses received from the WWW server are all represented by objects. This makes a simple and powerful interface to these services. The interface is easy to extend and customize for your own needs. The main features of the library are: =over 3 =item * Contains various reusable components (modules) that can be used separately or together. =item * Provides an object oriented model of HTTP-style communication. Within this framework we currently support access to http, https, gopher, ftp, news, file, and mailto resources. =item * Provides a full object oriented interface or a very simple procedural interface. =item * Supports the basic and digest authorization schemes. =item * Supports transparent redirect handling. =item * Supports access through proxy servers. =item * Provides parser for F files and a framework for constructing robots. =item * Supports parsing of HTML forms. =item * Implements HTTP content negotiation algorithm that can be used both in protocol modules and in server scripts (like CGI scripts). =item * Supports HTTP cookies. =item * Some simple command line clients, for instance C and C. =back =head1 HTTP STYLE COMMUNICATION The libwww-perl library is based on HTTP style communication. This section tries to describe what that means. Let us start with this quote from the HTTP specification document : =over 3 =item The HTTP protocol is based on a request/response paradigm. A client establishes a connection with a server and sends a request to the server in the form of a request method, URI, and protocol version, followed by a MIME-like message containing request modifiers, client information, and possible body content. The server responds with a status line, including the message's protocol version and a success or error code, followed by a MIME-like message containing server information, entity meta-information, and possible body content. =back What this means to libwww-perl is that communication always take place through these steps: First a I object is created and configured. This object is then passed to a server and we get a I object in return that we can examine. A request is always independent of any previous requests, i.e. the service is stateless. The same simple model is used for any kind of service we want to access. For example, if we want to fetch a document from a remote file server, then we send it a request that contains a name for that document and the response will contain the document itself. If we access a search engine, then the content of the request will contain the query parameters and the response will contain the query result. If we want to send a mail message to somebody then we send a request object which contains our message to the mail server and the response object will contain an acknowledgment that tells us that the message has been accepted and will be forwarded to the recipient(s). It is as simple as that! =head2 The Request Object The libwww-perl request object has the class name