NAME

       LWP::RobotUA - a class for well-behaved Web robots

SYNOPSIS

         use LWP::RobotUA;
         my $ua = LWP::RobotUA->new('my-robot/0.1', 'me@foo.com');
         $ua->delay(10);  # be very nice -- max one hit every ten minutes!
         ...

         # Then just use it just like a normal LWP::UserAgent:
         my $response = $ua->get('http://whatever.int/...');
         ...

DESCRIPTION

       This class implements a user agent that is suitable for robot applications.  Robots should
       be nice to the servers they visit.  They should consult the /robots.txt file to ensure
       that they are welcomed and they should not make requests too frequently.

       But before you consider writing a robot, take a look at <URL:http://www.robotstxt.org/>.

       When you use a LWP::RobotUA object as your user agent, then you do not really have to
       think about these things yourself; "robots.txt" files are automatically consulted and
       obeyed, the server isn't queried too rapidly, and so on.  Just send requests as you do
       when you are using a normal LWP::UserAgent object (using "$ua->get(...)",
       "$ua->head(...)", "$ua->request(...)", etc.), and this special agent will make sure you
       are nice.

METHODS

       The LWP::RobotUA is a sub-class of LWP::UserAgent and implements the same methods. In
       addition the following methods are provided:

       $ua = LWP::RobotUA->new( %options )
       $ua = LWP::RobotUA->new( $agent, $from )
       $ua = LWP::RobotUA->new( $agent, $from, $rules )
           The LWP::UserAgent options "agent" and "from" are mandatory.  The options "delay",
           "use_sleep" and "rules" initialize attributes private to the RobotUA.  If "rules" are
           not provided, then "WWW::RobotRules" is instantiated providing an internal database of
           robots.txt.

           It is also possible to just pass the value of "agent", "from" and optionally "rules"
           as plain positional arguments.

       $ua->delay
       $ua->delay( $minutes )
           Get/set the minimum delay between requests to the same server, in minutes.  The
           default is 1 minute.  Note that this number doesn't have to be an integer; for
           example, this sets the delay to 10 seconds:

               $ua->delay(10/60);

       $ua->use_sleep
       $ua->use_sleep( $boolean )
           Get/set a value indicating whether the UA should sleep() if requests arrive too fast,
           defined as $ua->delay minutes not passed since last request to the given server.  The
           default is TRUE.  If this value is FALSE then an internal SERVICE_UNAVAILABLE response
           will be generated.  It will have an Retry-After header that indicates when it is OK to
           send another request to this server.

       $ua->rules
       $ua->rules( $rules )
           Set/get which WWW::RobotRules object to use.

       $ua->no_visits( $netloc )
           Returns the number of documents fetched from this server host. Yeah I know, this
           method should probably have been named num_visits() or something like that. :-(

       $ua->host_wait( $netloc )
           Returns the number of seconds (from now) you must wait before you can make a new
           request to this host.

       $ua->as_string
           Returns a string that describes the state of the UA.  Mainly useful for debugging.

SEE ALSO

       LWP::UserAgent, WWW::RobotRules

COPYRIGHT

       Copyright 1996-2004 Gisle Aas.

       This library is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.