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 <http://www.robotstxt.org/>.

       When you use an 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:

   new
           my $ua = LWP::RobotUA->new( %options )
           my $ua = LWP::RobotUA->new( $agent, $from )
           my $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.

   delay
           my $delay = $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);

   use_sleep
           my $bool = $ua->use_sleep;
           $ua->use_sleep( $boolean );

       Get/set a value indicating whether the UA should "sleep" in LWP::RobotUA 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 a "Retry-After" header
       that indicates when it is OK to send another request to this server.

   rules
           my $rules = $ua->rules;
           $ua->rules( $rules );

       Set/get which WWW::RobotRules object to use.

   no_visits
           my $num = $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. :-(

   host_wait
           my $num = $ua->host_wait( $netloc )

       Returns the number of seconds (from now) you must wait before you can make a new request
       to this host.

   as_string
           my $string = $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.