HTML::LinkExtor - Extract links from an HTML document
require HTML::LinkExtor;
$p = HTML::LinkExtor->new(\&cb, "http://www.perl.org/");
sub cb {
my($tag, %links) = @_;
print "$tag @{[%links]}\n";
}
$p->parse_file("index.html");
User Contributed Perl Documentation HTML::LinkExtor(3)
NAME
HTML::LinkExtor - Extract links from an HTML document
SYNOPSIS
require HTML::LinkExtor;
$p = HTML::LinkExtor->new(\&cb, "http://www.perl.org/");
sub cb {
my($tag, %links) = @_;
print "$tag @{[%links]}\n";
}
$p->parse_file("index.html");
DESCRIPTION
HTML::LinkExtor is an HTML parser that extracts links from an HTML
document. The HTML::LinkExtor is a subclass of HTML::Parser. This
means that the document should be given to the parser by calling the
$p->parse() or $p->parse_file() methods.
$p = HTML::LinkExtor->new
$p = HTML::LinkExtor->new( $callback )
$p = HTML::LinkExtor->new( $callback, $base )
The constructor takes two optional arguments. The first is a
reference to a callback routine. It will be called as links are
found. If a callback is not provided, then links are just
accumulated internally and can be retrieved by calling the
$p->links() method.
The $base argument is an optional base URL used to absolutize all
URLs found. You need to have the URI module installed if you
provide $base.
The callback is called with the lowercase tag name as first
argument, and then all link attributes as separate key/value pairs.
All non-link attributes are removed.
$p->links
Returns a list of all links found in the document. The returned
values will be anonymous arrays with the following elements:
[$tag, $attr => $url1, $attr2 => $url2,...]
The $p->links method will also truncate the internal link list.
This means that if the method is called twice without any parsing
between them the second call will return an empty list.
Also note that $p->links will always be empty if a callback routine
was provided when the HTML::LinkExtor was created.
EXAMPLE
This is an example showing how you can extract links from a document
received using LWP:
use LWP::UserAgent;
use HTML::LinkExtor;
use URI::URL;
$url = "http://www.perl.org/"; # for instance
$ua = LWP::UserAgent->new;
# Set up a callback that collect image links
my @imgs = ();
sub callback {
my($tag, %attr) = @_;
return if $tag ne 'img'; # we only look closer at <img ...>
push(@imgs, values %attr);
}
# Make the parser. Unfortunately, we don't know the base yet
# (it might be different from $url)
$p = HTML::LinkExtor->new(\&callback);
# Request document and parse it as it arrives
$res = $ua->request(HTTP::Request->new(GET => $url),
sub {$p->parse($_[0])});
# Expand all image URLs to absolute ones
my $base = $res->base;
@imgs = map { $_ = url($_, $base)->abs; } @imgs;
# Print them out
print join("\n", @imgs), "\n";
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+---------------+----------------------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+----------------------------------+
|Availability | library/perl-5/html-entities-532 |
+---------------+----------------------------------+
|Stability | Volatile |
+---------------+----------------------------------+
SEE ALSO
HTML::Parser, HTML::Tagset, LWP, URI::URL
COPYRIGHT
Copyright 1996-2001 Gisle Aas.
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
NOTES
Source code for open source software components in Oracle Solaris can
be found at https://www.oracle.com/downloads/opensource/solaris-source-
code-downloads.html.
This software was built from source available at
https://github.com/oracle/solaris-userland. The original community
source was downloaded from
https://cpan.metacpan.org/authors/id/G/GA/GAAS/HTML-Parser-3.72.tar.gz.
Further information about this software can be found on the open source
community website at https://metacpan.org/pod/HTML::Entities.
perl v5.32.0 2013-10-21 HTML::LinkExtor(3)