What Is LWP::UserAgent?

Perl Tutorials - Herong's Tutorial Examples

∟LWP::UserAgent and Web Site Testing

∟What Is LWP::UserAgent?

This section describes what is LWP::UserAgent - a Perl class that helps you to prepare a HTTP request, send it to a Web server, then receive the HTTP response from the Web server.

What Is LWP::UserAgent? LWP::UserAgent, developed by Gisle Aas, is a Perl class that helps you to prepare a HTTP request, send it to a Web server, then receive the HTTP response from the Web server.

In normal use, the application creates an LWP::UserAgent object, and then configures it with values for timeouts, proxies, name, etc. It then creates an instance of HTTP::Request for the request that needs to be performed. This request is then passed to one of the request method the UserAgent, which dispatches it using the relevant protocol, and returns a HTTP::Response object. There are convenience methods for sending the most common request types: get(), head(), post(), put() and delete().

The current version of LWP::UserAgent is 6.05, which supports the following main properties and methods:

agent() - Get/set the product token that is used to identify the user agent on the network. Default is "libwww-perl/#.###".
cookie_jar() - Get/set the cookie jar (HTTP::Cookies) object to store cookies.
default_headers() - Get/set the headers (HTTP::Headers) object that will provide default header values for any requests sent.
credentials() - Get/set the user name and password to be used for a realm.
ssl_opts() - Get/set the options for SSL connections.
proxy() - Set/retrieve proxy URL for a scheme.
add_handler() - Add handler to be invoked in the given processing phase.
remove_handler() - Remove handler.
get() - Dispatch a GET request on the given $url. The return value is a response (HTTP::Response) object.
post() - Dispatch a POST request on the given $url. The return value is a response (HTTP::Response) object.
request() - Dispatch the given request (HTTP::Request) object. The return value is a response (HTTP::Response) object.

Now let's run a simple test on the LWP::UserAgent class using the Perl command line:

herong> perl -e "use LWP::UserAgent;
   print((new LWP::UserAgent())->get('http://herongyang.com'));"

HTTP::Response=HASH(0x19f7fcc)

Great. The simple test worked and I got an HTTP::Response object. See the next tutorial on how to work with HTTP::Response objects.

Table of Contents

About This Book

Perl on Linux Systems

ActivePerl on Windows Systems

Data Types: Values and Variables

Expressions, Operations and Simple Statements

User Defined Subroutines

Perl Built-in Debugger

Name Spaces and Perl Module Files

Symbolic (or Soft) References

Hard References - Addresses of Memory Objects

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Typeglob and Importing Identifiers from Other Packages

String Built-in Functions and Performance

File Handles and Data Input/Output

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Image and Picture Processing

Using DBM Database Files

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Socket Communication Over the Internet

XML::Simple Module - XML Parser and Generator

XML Communication Model

SOAP::Lite - SOAP Server-Client Communication Module

Perl Programs as IIS Server CGI Scripts

CGI (Common Gateway Interface)

XML-RPC - Remote Procedure Call with XML and HTTP

RPC::XML - Perl Implementation of XML-RPC

Integrating Perl with Apache Web Server

CGI.pm Module for Building Web Pages

►LWP::UserAgent and Web Site Testing

►What Is LWP::UserAgent?

What Is HTTP::Response?

What Is HTTP::Request?

LWP-UserAgent-GET.pl - Sending a GET Request

LWP-UserAgent-GET-Redirect.pl - Following HTTP Redirects

http-equiv="Refresh" Meta Tag not Followed

LWP-UserAgent-POST.pl - Posting Form Data

post() Method not Following Redirect Location

LWP-UserAgent-POST-Redirect.pl - Posting with Redirects

What Is HTTP::Cookies?

LWP-UserAgent-Request.pl - GET, POST and Cookies

LWP-UserAgent-Request.pl - Login to facebook.com

HTTP::Cookies save() not Saving Temporary Cookies

LWP-UserAgent-Request-Cookies.pl - Sending Request with Cookies

Converting Perl Script to Executable Binary

Managing Perl Engine and Modules on macOS

Archived Tutorials

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