WWW (3)
Leading comments
World Wide Web Package WWW.3 Copyright (C) 1998 Paul J. Lucas This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. ...
NAME
WWW - World Wide Web PackageSYNOPSIS
extract_description( FILE ) extract_meta( FILE, NAME ) hyperlink( LIST )
DESCRIPTION
This package provides a utility functions for the World Wide Web to extract descriptions of or meta information from files, and hyperlink text.SUBROUTINES
The following Perl subroutines are defined and available:- extract_description( FILE )
- Extracts a description from an HTML or plain text file given by the FILE name; FILE should be an absolute path. The first $description::chars (default: 2048) characters are read. If the file ends in one of the extensions htm, html, or shtml, it is presumed to be an HTML file; if the file ends in txt, it is presumed to be a plain text file. Other extensions are not recognized and no description is returned for them.
- For HTML files, first, if a <META NAME="description" CONTENT="..."> or a <META NAME="DC.description" CONTENT="..."> (Dublin Core) element is found, then the words specified as the value of the CONTENT attribute is returned as the description.
- Otherwise, all HTML comments, text between <SCRIPT>, <STYLE>, and <TITLE> tags, and all other HTML tags are stripped. If <AREA ... ALT="..."> or <IMG ... ALT="..."> elements are found, then the words specified as the value of the ALT attributes are extracted.
- Finally, for either HTML or plain text files, at most $description::words (default: 50) are returned.
- extract_meta( FILE, NAME )
- Extracts the value of the CONTENT attribute from a META element having the given NAME attribute from an HTML file given by the FILE name; FILE should be an absolute path. The file must end in one of the extensions htm, html, or shtml to be considered an HTML file. The first $description::chars (default: 2048) characters are read. The characters are cached between consecutive calls using the same filename.
- hyperlink( LIST )
-
Adds hyperlinks to strings:
that is strings that contain substrings that are valid URLs
(according to RFC 1630)
have the appropriate HTML tags ``wrapped'' around them so that they will be
selectable when displayed in a browser.
The ftp, gopher, http, https, mailto,
news, telnet, and wais URLs are recognized.
Example:
- Read all about it at www.usatoday.com becomes: Read all about it at <A HREF="www.usatoday.com">www.usatoday.com</A>
SEE ALSO
perl(1)Tim Berners-Lee. ``Universal Resource Identifiers in WWW,'' Request for Comments 1630, Network Working Group of the Internet Engineering Task Force, June 1994.
Tim Berners-Lee, Larry Masinter, and Mark McCahill. ``Uniform Resource Locators (URL),'' Request for Comments 1738, Network Working Group, 1994.
Dave Raggett, Arnaud Le Hors, and Ian Jacobs. ``Notes on helping search engines index your Web site,'' HTML 4.0 Specification, Appendix B: Performance, Implementation, and Design Notes, World Wide Web Consortium, April 1998.
--. ``Objects, Images, and Applets: How to specify alternate text,'' HTML 4.0 Specification, §13.8, World Wide Web Consortium, April 1998.
Dublin Core Directorate. ``The Dublin Core: A Simple Content Description Model for Electronic Resources.''
Larry Wall, et al. Programming Perl, 3rd ed., O'Reilly & Associates, Inc., Sebastopol, CA, 2000.