use LWP::RobotUA; my $ua = LWP::RobotUA->new('my-robot/0.1', 'email@example.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 = $ua->get('http://whatever.int/...'); ...
But before you consider writing a robot, take a look at <URL:http://www.robotstxt.org/>.
When you use an LWP::RobotUA object as your user agent, then you do not really have to think about these things yourself; "robots.txt" files are automatically consulted and obeyed, the server isn't queried too rapidly, and so on. Just send requests as you do when you are using a normal LWP::UserAgent object (using "$ua->get(...)", "$ua->head(...)", "$ua->request(...)", etc.), and this special agent will make sure you are nice.
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.
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:
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.
my $rules = $ua->rules; $ua->rules( $rules );
my $num = $ua->no_visits( $netloc )
my $num = $ua->host_wait( $netloc )
my $string = $ua->as_string;
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.