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✏️ Editing: LWP::RobotUA.3pm

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.\" ========================================================================
.\"
.IX Title "LWP::RobotUA 3"
.TH LWP::RobotUA 3 "2024-01-25" "perl v5.26.3" "User Contributed Perl Documentation"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
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.nh
.SH "NAME"
LWP::RobotUA \- a class for well\-behaved Web robots
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 4
\&  use LWP::RobotUA;
\&  my $ua = LWP::RobotUA\->new(\*(Aqmy\-robot/0.1\*(Aq, \*(Aqme@foo.com\*(Aq);
\&  $ua\->delay(10);  # be very nice \-\- max one hit every ten minutes!
\&  ...
\&
\&  # Then just use it just like a normal LWP::UserAgent:
\&  my $response = $ua\->get(\*(Aqhttp://whatever.int/...\*(Aq);
\&  ...
.Ve
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
This class implements a user agent that is suitable for robot
applications.  Robots should be nice to the servers they visit.  They
should consult the \fI/robots.txt\fR file to ensure that they are welcomed
and they should not make requests too frequently.
.PP
But before you consider writing a robot, take a look at
<http://www.robotstxt.org/>.
.PP
When you use an \fILWP::RobotUA\fR object as your user agent, then you do not
really have to think about these things yourself; \f(CW\*(C`robots.txt\*(C'\fR files
are automatically consulted and obeyed, the server isn't queried
too rapidly, and so on.  Just send requests
as you do when you are using a normal \fILWP::UserAgent\fR
object (using \f(CW\*(C`$ua\->get(...)\*(C'\fR, \f(CW\*(C`$ua\->head(...)\*(C'\fR,
\&\f(CW\*(C`$ua\->request(...)\*(C'\fR, etc.), and this
special agent will make sure you are nice.
.SH "METHODS"
.IX Header "METHODS"
The LWP::RobotUA is a sub-class of LWP::UserAgent and implements the
same methods. In addition the following methods are provided:
.SS "new"
.IX Subsection "new"
.Vb 3
\&    my $ua = LWP::RobotUA\->new( %options )
\&    my $ua = LWP::RobotUA\->new( $agent, $from )
\&    my $ua = LWP::RobotUA\->new( $agent, $from, $rules )
.Ve
.PP
The LWP::UserAgent options \f(CW\*(C`agent\*(C'\fR and \f(CW\*(C`from\*(C'\fR are mandatory.  The
options \f(CW\*(C`delay\*(C'\fR, \f(CW\*(C`use_sleep\*(C'\fR and \f(CW\*(C`rules\*(C'\fR initialize attributes
private to the RobotUA.  If \f(CW\*(C`rules\*(C'\fR are not provided, then
WWW::RobotRules is instantiated providing an internal database of
\&\fIrobots.txt\fR.
.PP
It is also possible to just pass the value of \f(CW\*(C`agent\*(C'\fR, \f(CW\*(C`from\*(C'\fR and
optionally \f(CW\*(C`rules\*(C'\fR as plain positional arguments.
.SS "delay"
.IX Subsection "delay"
.Vb 2
\&    my $delay = $ua\->delay;
\&    $ua\->delay( $minutes );
.Ve
.PP
Get/set the minimum delay between requests to the same server, in
\&\fIminutes\fR.  The default is \f(CW1\fR minute.  Note that this number doesn't
have to be an integer; for example, this sets the delay to \f(CW10\fR seconds:
.PP
.Vb 1
\&    $ua\->delay(10/60);
.Ve
.SS "use_sleep"
.IX Subsection "use_sleep"
.Vb 2
\&    my $bool = $ua\->use_sleep;
\&    $ua\->use_sleep( $boolean );
.Ve
.PP
Get/set a value indicating whether the \s-1UA\s0 should \*(L"sleep\*(R" in LWP::RobotUA if
requests arrive too fast, defined as \f(CW\*(C`$ua\->delay\*(C'\fR minutes not passed since
last request to the given server.  The default is true.  If this value is
false then an internal \f(CW\*(C`SERVICE_UNAVAILABLE\*(C'\fR response will be generated.
It will have a \f(CW\*(C`Retry\-After\*(C'\fR header that indicates when it is \s-1OK\s0 to
send another request to this server.
.SS "rules"
.IX Subsection "rules"
.Vb 2
\&    my $rules = $ua\->rules;
\&    $ua\->rules( $rules );
.Ve
.PP
Set/get which \fIWWW::RobotRules\fR object to use.
.SS "no_visits"
.IX Subsection "no_visits"
.Vb 1
\&    my $num = $ua\->no_visits( $netloc )
.Ve
.PP
Returns the number of documents fetched from this server host. Yeah I
know, this method should probably have been named \f(CW\*(C`num_visits\*(C'\fR or
something like that. :\-(
.SS "host_wait"
.IX Subsection "host_wait"
.Vb 1
\&    my $num = $ua\->host_wait( $netloc )
.Ve
.PP
Returns the number of \fIseconds\fR (from now) you must wait before you can
make a new request to this host.
.SS "as_string"
.IX Subsection "as_string"
.Vb 1
\&    my $string = $ua\->as_string;
.Ve
.PP
Returns a string that describes the state of the \s-1UA.\s0
Mainly useful for debugging.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
LWP::UserAgent, WWW::RobotRules
.SH "COPYRIGHT"
.IX Header "COPYRIGHT"
Copyright 1996\-2004 Gisle Aas.
.PP
This library is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.

MR SKB