Skip to content

schwern/URI-Find

Repository files navigation

NAME

    URI::Find - Find URIs in arbitrary text

SYNOPSIS

      require URI::Find;
    
      my $finder = URI::Find->new(\&callback);
    
      $how_many_found = $finder->find(\$text);

DESCRIPTION

    This module does one thing: Finds URIs and URLs in plain text. It finds
    them quickly and it finds them all (or what URI.pm considers a URI to
    be.) It only finds URIs which include a scheme (http:// or the like),
    for something a bit less strict have a look at URI::Find::Schemeless.

    For a command-line interface, urifind is provided.

 Public Methods

    new

        my $finder = URI::Find->new(\&callback);

      Creates a new URI::Find object.

      &callback is a function which is called on each URI found. It is
      passed two arguments, the first is a URI object representing the URI
      found. The second is the original text of the URI found. The return
      value of the callback will replace the original URI in the text.

    find

        my $how_many_found = $finder->find(\$text);

      $text is a string to search and possibly modify with your callback.

      Alternatively, find can be called with a replacement function for the
      rest of the text:

        use CGI qw(escapeHTML);
        # ...
        my $how_many_found = $finder->find(\$text, \&escapeHTML);

      will not only call the callback function for every URL found (and
      perform the replacement instructions therein), but also run the rest
      of the text through escapeHTML(). This makes it easier to turn plain
      text which contains URLs into HTML (see example below).

 Protected Methods

    I got a bunch of mail from people asking if I'd add certain features to
    URI::Find. Most wanted the search to be less restrictive, do more
    heuristics, etc... Since many of the requests were contradictory, I'm
    letting people create their own custom subclasses to do what they want.

    The following are methods internal to URI::Find which a subclass can
    override to change the way URI::Find acts. They are only to be called
    inside a URI::Find subclass. Users of this module are NOT to use these
    methods.

    uri_re

        my $uri_re = $self->uri_re;

      Returns the regex for finding absolute, schemed URIs
      (http://www.foo.com and such). This, combined with
      schemeless_uri_re() is what finds candidate URIs.

      Usually this method does not have to be overridden.

    schemeless_uri_re

        my $schemeless_re = $self->schemeless_uri_re;

      Returns the regex for finding schemeless URIs (www.foo.com and such)
      and other things which might be URIs. By default this will match
      nothing (though it used to try to find schemeless URIs which started
      with www and ftp).

      Many people will want to override this method. See
      URI::Find::Schemeless for a subclass does a reasonable job of finding
      URIs which might be missing the scheme.

    uric_set

        my $uric_set = $self->uric_set;

      Returns a set matching the 'uric' set defined in RFC 2396 suitable
      for putting into a character set ([]) in a regex.

      You almost never have to override this.

    cruft_set

        my $cruft_set = $self->cruft_set;

      Returns a set of characters which are considered garbage. Used by
      decruft().

    decruft

        my $uri = $self->decruft($uri);

      Sometimes garbage characters like periods and parenthesis get
      accidentally matched along with the URI. In order for the URI to be
      properly identified, it must sometimes be "decrufted", the garbage
      characters stripped.

      This method takes a candidate URI and strips off any cruft it finds.

    recruft

        my $uri = $self->recruft($uri);

      This method puts back the cruft taken off with decruft(). This is
      necessary because the cruft is destructively removed from the string
      before invoking the user's callback, so it has to be put back
      afterwards.

    schemeless_to_schemed

        my $schemed_uri = $self->schemeless_to_schemed($schemeless_uri);

      This takes a schemeless URI and returns an absolute, schemed URI. The
      standard implementation supplies ftp:// for URIs which start with
      ftp., and http:// otherwise.

    is_schemed

        $obj->is_schemed($uri);

      Returns whether or not the given URI is schemed or schemeless. True
      for schemed, false for schemeless.

    badinvo

        __PACKAGE__->badinvo($extra_levels, $msg)

      This is used to complain about bogus subroutine/method invocations.
      The args are optional.

 Old Functions

    The old find_uri() function is still around and it works, but its
    deprecated.

EXAMPLES

    Store a list of all URIs (normalized) in the document.

      my @uris;
      my $finder = URI::Find->new(sub {
          my($uri) = shift;
          push @uris, $uri;
      });
      $finder->find(\$text);

    Print the original URI text found and the normalized representation.

      my $finder = URI::Find->new(sub {
          my($uri, $orig_uri) = @_;
          print "The text '$orig_uri' represents '$uri'\n";
          return $orig_uri;
      });
      $finder->find(\$text);

    Check each URI in document to see if it exists.

      use LWP::Simple;
    
      my $finder = URI::Find->new(sub {
          my($uri, $orig_uri) = @_;
          if( head $uri ) {
              print "$orig_uri is okay\n";
          }
          else {
              print "$orig_uri cannot be found\n";
          }
          return $orig_uri;
      });
      $finder->find(\$text);

    Turn plain text into HTML, with each URI found wrapped in an HTML
    anchor.

      use CGI qw(escapeHTML);
      use URI::Find;
    
      my $finder = URI::Find->new(sub {
          my($uri, $orig_uri) = @_;
          return qq|<a href="$uri">$orig_uri</a>|;
      });
      $finder->find(\$text, \&escapeHTML);
      print "<pre>$text</pre>";

NOTES

    Will not find URLs with Internationalized Domain Names or pretty much
    any non-ascii stuff in them. See
    http://rt.cpan.org/Ticket/Display.html?id=44226

AUTHOR

    Michael G Schwern <[email protected]> with insight from Uri Gutman,
    Greg Bacon, Jeff Pinyan, Roderick Schertler and others.

    Roderick Schertler <[email protected]> maintained versions 0.11 to
    0.16.

    Darren Chamberlain wrote urifind.

LICENSE

    Copyright 2000, 2009-2010, 2014, 2016 by Michael G Schwern
    <[email protected]>.

    This program is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself.

    See http://www.perlfoundation.org/artistic_license_1_0

SEE ALSO

    urifind, URI::Find::Schemeless, URI, RFC 3986 Appendix C