1LWP::RobotUA(3)       User Contributed Perl Documentation      LWP::RobotUA(3)
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NAME

6       LWP::RobotUA - a class for well-behaved Web robots
7

SYNOPSIS

9         use LWP::RobotUA;
10         my $ua = LWP::RobotUA->new('my-robot/0.1', 'me@foo.com');
11         $ua->delay(10);  # be very nice -- max one hit every ten minutes!
12         ...
13
14         # Then just use it just like a normal LWP::UserAgent:
15         my $response = $ua->get('http://whatever.int/...');
16         ...
17

DESCRIPTION

19       This class implements a user agent that is suitable for robot
20       applications.  Robots should be nice to the servers they visit.  They
21       should consult the /robots.txt file to ensure that they are welcomed
22       and they should not make requests too frequently.
23
24       But before you consider writing a robot, take a look at
25       <URL:http://www.robotstxt.org/>.
26
27       When you use an LWP::RobotUA object as your user agent, then you do not
28       really have to think about these things yourself; "robots.txt" files
29       are automatically consulted and obeyed, the server isn't queried too
30       rapidly, and so on.  Just send requests as you do when you are using a
31       normal LWP::UserAgent object (using "$ua->get(...)", "$ua->head(...)",
32       "$ua->request(...)", etc.), and this special agent will make sure you
33       are nice.
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METHODS

36       The LWP::RobotUA is a sub-class of LWP::UserAgent and implements the
37       same methods. In addition the following methods are provided:
38
39   new
40           my $ua = LWP::RobotUA->new( %options )
41           my $ua = LWP::RobotUA->new( $agent, $from )
42           my $ua = LWP::RobotUA->new( $agent, $from, $rules )
43
44       The LWP::UserAgent options "agent" and "from" are mandatory.  The
45       options "delay", "use_sleep" and "rules" initialize attributes private
46       to the RobotUA.  If "rules" are not provided, then "WWW::RobotRules" is
47       instantiated providing an internal database of robots.txt.
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49       It is also possible to just pass the value of "agent", "from" and
50       optionally "rules" as plain positional arguments.
51
52   delay
53           my $delay = $ua->delay;
54           $ua->delay( $minutes );
55
56       Get/set the minimum delay between requests to the same server, in
57       minutes.  The default is 1 minute.  Note that this number doesn't have
58       to be an integer; for example, this sets the delay to 10 seconds:
59
60           $ua->delay(10/60);
61
62   use_sleep
63           my $bool = $ua->use_sleep;
64           $ua->use_sleep( $boolean );
65
66       Get/set a value indicating whether the UA should "sleep" in
67       LWP::RobotUA if requests arrive too fast, defined as "$ua->delay"
68       minutes not passed since last request to the given server.  The default
69       is true.  If this value is false then an internal "SERVICE_UNAVAILABLE"
70       response will be generated.  It will have a "Retry-After" header that
71       indicates when it is OK to send another request to this server.
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73   rules
74           my $rules = $ua->rules;
75           $ua->rules( $rules );
76
77       Set/get which WWW::RobotRules object to use.
78
79   no_visits
80           my $num = $ua->no_visits( $netloc )
81
82       Returns the number of documents fetched from this server host. Yeah I
83       know, this method should probably have been named "num_visits" or
84       something like that. :-(
85
86   host_wait
87           my $num = $ua->host_wait( $netloc )
88
89       Returns the number of seconds (from now) you must wait before you can
90       make a new request to this host.
91
92   as_string
93           my $string = $ua->as_string;
94
95       Returns a string that describes the state of the UA.  Mainly useful for
96       debugging.
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SEE ALSO

99       LWP::UserAgent, WWW::RobotRules
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102       Copyright 1996-2004 Gisle Aas.
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104       This library is free software; you can redistribute it and/or modify it
105       under the same terms as Perl itself.
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109perl v5.30.2                      2020-04-15                   LWP::RobotUA(3)
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