Lukas Mai
and 1 contributors

NAME

URL::Search - search for URLs in plain text

SYNOPSIS

  use URL::Search qw( $URL_SEARCH_RE extract_urls partition_urls );

  if ($text =~ /($URL_SEARCH_RE)/) {
      print "the first URL in text was: $1\n";
  }

  my @all_urls = extract_urls $text;

DESCRIPTION

This module searches plain text for URLs and extracts them. It exports (on request) the following entities:

$URL_SEARCH_RE

This variable is the core of this module. It contains a regex that matches a URL.

NOTE: This regex uses capturing groups internally, so if you embed it in a bigger pattern, the numbering of any following capture groups will be off.

It only matches URLs with an explicit schema (one of http, https, ftp, ftps). The pattern is deliberately not anchored at the beginning, i.e. it will match http://foo in "click herehttp://foo". If you don't want that, use /\b$URL_SEARCH_RE/.

It tries to exclude artifacts of the surrounding text:

  Is mayonnaise an instrument? (https://en.wikipedia.org/wiki/Instrument,
  https://en.wikipedia.org/wiki/Mayonnaise_(instrument))

In this example it will match https://en.wikipedia.org/wiki/Instrument and https://en.wikipedia.org/wiki/Mayonnaise_(instrument), without the comma after "Instrument" and the final closing parenthesis.

It understands all common URL elements: username, hostname, port, path, query string, fragment identifier. The hostname can be an IP address (IPv4 and IPv6 are both supported).

Unicode is supported (e.g. http://поддомен.example.com/déjà-vu?utf8=✓ is matched correctly).

extract_urls

This function takes a string and returns a list of all contained URLs.

It uses $URL_SEARCH_RE to find matches.

Example:

  my $text = 'Visit us at http://html5zombo.com. Also, https://archive.org';
  my @urls = extract_urls $text;
  # @urls = ('http://html5zombo.com', 'https://archive.org')

partition_urls

This function takes a string and splits it up into text and URL segments. It returns a list of array references, each of which has two elements: The type (the string 'TEXT' or 'URL') and the portion of the input string that was classified as text or URL, respectively.

Example:

  my $text = 'Visit us at http://html5zombo.com. Also, https://archive.org';
  my @parts = partition_urls $text;
  # @parts = (
  #   [ 'TEXT', 'Visit us at ' ],
  #   [ 'URL', 'http://html5zombo.com' ],
  #   [ 'TEXT', '. Also, ' ],
  #   [ 'URL', 'https://archive.org' ],
  # )

You can reassemble the original string by concatenating the second elements of the returned arrayrefs, i.e. join('', map { $_->[1] } partition_urls($text)) eq $text.

This function can be useful if you want to render plain text as HTML but hyperlink all embedded URLs:

  use URL::Search qw(partition_urls);
  use HTML::Entities qw(encode_entities);

  my $text = ...;

  my $html = '';
  for my $part (partition_urls $text) {
      my ($type, $str) = @$part;
      $str = encode_entities $str;
      if ($type eq 'URL') {
          $html .= "<a rel='nofollow' href='$str'>$str</a>";
      } else {
          $html .= $str;
      }
  }
  # result is in $html

SUPPORT AND DOCUMENTATION

After installing, you can find documentation for this module with the perldoc command.

    perldoc URL::Search

You can also look for information at https://metacpan.org/pod/URL::Search.

To see a list of open bugs, visit https://rt.cpan.org/Public/Dist/Display.html?Name=URL-Search.

To report a new bug, send an email to bug-URL-Search [at] rt.cpan.org.

AUTHOR

Lukas Mai, <l.mai at web.de>

COPYRIGHT & LICENSE

Copyright 2016, 2017 Lukas Mai.

This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License.

See http://dev.perl.org/licenses/ for more information.