NAME URL::Normalize - Normalize/optimize URLs.

VERSION Version 0.11

SYNOPSIS use URL::Normalize;

    my $Normalizer = URL::Normalize->new(
        url => 'http://www.example.com/display?lang=en&article=fred',
    );

    # ...or

    my $Normalizer = URL::Normalize->new(
        url  => '/display?lang=en&article=fred',
        base => 'http://www.example.com',
    );

    # Get a normalized URL back

    $Normalizer->do_all(); # Perform all the normalizations available

    print $Normalizer->get_url();

DESCRIPTION This is NOT a perfect solution. If you normalize a URL using all the methods in this module, there is a high probability that the URL will "stop working". This is merely a helper module for those of you who wants to either normalize a URL using only a few of the safer methods, and/or for those of you who wants to generate a unique "ID" from any given URL.

When writing a web crawler, for example, it's always very costly to
check if a URL has been fetched/seen when you have millions or billions
of URLs in a sort of database. This module can help you create a unique
"ID", which you then can use as a key in a key/value-store; the key is
the normalized URL, whereas all the URLs that converts to the normalized
URL are part of the value (normally an array or hash);

    'http://www.example.com/' = {
        'http://www.example.com:80/'        => 1,
        'http://www.example.com/index.html' => 1,
        'http://www.example.com/?'          => 1,
    }

Above, all the URLs inside the hash normalizes to the key if you run
these methods:

* `make_canonical()'
* `remove_directory_index()'
* `remove_empty_query()'

CONSTRUCTORS new( %opts ) Constructs a new URL::Normalize object. Takes a hash as input argument;

    my $Normalizer = URL::Normalize->new(
        url  => '/foobar.html',            # required
        base => 'http://www.example.com/', # optional
    );

METHODS get_URI() Returns the `URI' object representing the current state of the URL.

get_url() Returns the current URL.

get_base() Returns the current base.

make_canonical() Just a shortcut for URI::URL->new()->canonical()->as_string(), and involves the following steps (at least):

* Converts the scheme and host to lower case.
* Capitalizes letters in escape sequences.
* Decodes percent-encoded octets of unreserved characters.
* Removes the default port (port 80 for http).

Example:

    my $Normalizer = URL::Normalize->new(
        url => 'http://www.example.com/%7Eusername/',
    );

    $Normalize->make_canonical();

    print $Normalize->get_url(); # http://www.example.com/~username/

remove_dot_segments() The segments ".." and "." will be removed from the URL according to the algorithm described in RFC 3986.

Example:

    my $Normalizer = URL::Normalize->new(
        url => 'http://www.example.com/../a/b/../c/./d.html',
    );

    $Normalize->remove_dot_segments();

    print $Normalize->get_url(); # http://www.example.com/a/c/d.html

remove_directory_index() Removes well-known directory indexes, eg. "index.html", "default.asp" etc.

Example:

    my $Normalizer = URL::Normalize->new(
        url => 'http://www.example.com/index.cgi?foo=/',
    );

    $Normalizer->remove_directory_index();

    print $Normalizer->get_url(); # http://www.example.com/?foo=/

You are free to modify the global `$DIRECTORY_INDEX_REGEXPS' arrayref to
your own fitting:

    $URL::Normalize::DIRECTORY_INDEX_REGEXPS = [ ... ];

    my $Normalizer = URL::Normalize->new(
        url => 'http://www.example.com/index.cgi?foo=/',
    );

    $Normalizer->remove_directory_index();

    print $Normalizer->get_url(); # whatever

sort_query_parameters() Sorts the query parameters alphabetically.

Uppercased parameters will be lower cased during sorting only, and if
there are multiple values for a parameter, the key/value-pairs will be
sorted as well.

Example:

    my $Normalizer = URL::Normalize->new(
        url => 'http://www.example.com/?b=2&c=3&a=0&A=1',
    );

    $Normalizer->sort_query_parameters();

    print $Normalizer->get_url(); # http://www.example.com/?a=0&A=1&b=2&c=3

remove_duplicate_query_parameters() Removes duplicate query parameters, ie. where the key/value combination is identical with another key/value combination.

Example:

    my $Normalizer = URL::Normalize->new(
        url => 'http://www.example.com/?a=1&a=2&b=4&a=1&c=4',
    );

    $Normalizer->remove_duplicate_query_parameters();

    print $Normalizer->get_url(); # http://www.example.com/?a=1&a=2&b=3&c=4

remove_empty_query_parameters() Removes empty query parameters, ie. where there are keys with no value.

Example:

    my $Normalizer = URL::Normalize->new(
        url => 'http://www.example.com/?a=1&b=&c=3',
    );

    $Normalize->remove_empty_query_parameters();

    print $Normalizer->get_url(); # http://www.example.com/?a=1&c=3

remove_empty_query() Removes empty query from the URL.

Example:

    my $Normalizer = URL::Normalize->new(
        url => 'http://www.example.com/foo?',
    );

    $Normalizer->remove_empty_query();

    print $Normalize->get_url(); # http://www.example.com/foo

remove_fragment() Removes fragments from the URL.

Example:

    my $Normalizer = URL::Normalize->new(
        url => 'http://www.example.com/bar.html#section1',
    );

    $Normalizer->remove_fragment();

    print $Normalizer->get_url(); # http://www.example.com/bar.html

remove_duplicate_slashes() Remove duplicate slashes from the URL.

Example:

    my $Normalizer = URL::Normalize->new(
        url => 'http://www.example.com/foo//bar.html',
    );

    $Normalizer->remove_duplicate_slashes();

    print $Normalizer->get_url(); # http://www.example.com/foo/bar.html

remove_hostname_prefix() Removes 'www' followed by a potential number before the actual hostname.

Example:

    my $Normalizer = URL::Normalize->new(
        url => 'http://www.example.com/',
    );

    $Normalizer->remove_hostname_prefix();

    print $Normalizer->get_url(); # http://example.com/

do_all() Performs all of the normalization methods mentioned above.

PERFORMANCE There's probably possible to improve the performance of this module considerably, but as premature optimization is evil, I'll wait until the functionality and API is stable.

On my MacBook Pro (2.66GHz i7, 8GB RAM) running Perl 5.14.2, I'm able to
run the do_all() method on more than 1,100 URLs per second. This is just
a number, as the performance depends on the complexity of the URL.

SEE ALSO * URI * URI::URL * URI::QueryParam * RFC 3986: Uniform Resource Indentifier * Wikipedia: URL normalization

AUTHOR Tore Aursand, `'

BUGS Please report any bugs or feature requests to the web interface at https://github.com/toreau/url-normalize/issues/new.

SUPPORT You can find documentation for this module with the perldoc command.

    perldoc URL::Normalize

You can also look for information at:

* github (report bugs here)
    https://github.com/toreau/url-normalize/issues

* AnnoCPAN: Annotated CPAN documentation
    http://annocpan.org/dist/URL-Normalize

* CPAN Ratings
    http://cpanratings.perl.org/d/URL-Normalize

* Search CPAN
    http://search.cpan.org/dist/URL-Normalize/

LICENSE AND COPYRIGHT Copyright 2012 Tore Aursand.

This program is free software; you can redistribute it and/or modify it
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