From e0c6872cf40896c7be36b11dcc744620f10adf1d Mon Sep 17 00:00:00 2001 From: Norbert Preining Date: Mon, 2 Sep 2019 13:46:59 +0900 Subject: Initial commit --- usergrps/uktug/baskervi/3_2/drakos.tex | 238 +++++++++++++++++++++++++++++++++ 1 file changed, 238 insertions(+) create mode 100644 usergrps/uktug/baskervi/3_2/drakos.tex (limited to 'usergrps/uktug/baskervi/3_2/drakos.tex') diff --git a/usergrps/uktug/baskervi/3_2/drakos.tex b/usergrps/uktug/baskervi/3_2/drakos.tex new file mode 100644 index 0000000000..22315ab931 --- /dev/null +++ b/usergrps/uktug/baskervi/3_2/drakos.tex @@ -0,0 +1,238 @@ +\def\latextohtml{\LaTeX{2}{\tt{HTML}} } +\def\htmladdnormallink#1#2{ #1\footnote{#2}} +\def\bull{$\bullet $ } + +% MYFIG +% #1 - name without the .ps extension +% #2 - caption +% Frames the picture. +\newcommand{\myfig}[2] + {\begin{figure*} + \centerline{% + \epsfig{file=#1.ps,height=.9\textheight}} + \caption{#2} + \label{fig:#1} + \end{figure*}} + + +\title{Text to Hypertext Conversion with \latextohtml} +\author[Nikos Drakos]{Nikos Drakos,\\ Computer Based Learning Unit,\\ +University of Leeds, Leeds LS2 9JT, UK.\\ +email: {\tt nikos@cbl.leeds.ac.uk}\\ +www: {\tt http://cbl.leeds.ac.uk/nikos/personal.html}\\ +} + +\begin{article} +\begin{abstract} +\latextohtml is a conversion tool that allows existing documents +written in \LaTeX\ to become part of a global multimedia system. +This paper presents some of the reasons for using such a system and +describes the basic conversion process. +\end{abstract} + +\section{World Wide Web --- A Global Multimedia System} +\begin{quotation} +Imagine a system that links all the text, data, digital sounds, +graphics and video on all the world's computers into a single +interlinked hypermedia ``web''. This is the potential of the +Internet-based +World Wide Web (WWW or W3) project \ldots \cite{levy:www} +\end{quotation} + +The World Wide Web merges hypermedia techniques with networked +document retrieval to provide a global information system of linked +documents. These are traversed by ``clicking'' in textual or iconic +active areas, or searched via query mechanisms \cite{tbl:www}. Hypertext links +may point to a different location in the same document or to another +document which may be located perhaps in another continent! + +Documents are not limited to containing only textual information +and may include high resolution images, audio and video samples. +WWW also encompasses most of the services currently available on the +Internet such as Usenet news, ftp, wais, archie, etc. Access +to these services as well as the invocation of arbitrary computer +programs (e.g.\ a database access or a simulation) is completely +transparent to the user who sees them all +as part of some document and interacts with them in a uniform +and intuitive way. + +Multimedia documents are written in a language designed specifically +for the World Wide Web called HTML (HyperText Markup Language) which +is based on SGML (Structured Generalised Markup Language). Documents +are written by information providers who just place them on the WWW +using a ``server'' program. Then anyone with access to the Internet +can use a ``client'' or ``browser'' program to access and view +available documents. Clients and servers communicate via the HTTP +protocol (HyperText Transfer Protocol). Apart from navigation +facilities, browsers also allow full text searches, ``cut and paste'', +text or audio annotations, personal ``hotlists'', saving and printing +in multiple formats and others. Such browser and server programs are +freely available for most popular computer configurations. + +With the explosive growth of the World Wide Web (500-fold since the +first graphical browsers were made available this year \cite{vern:www}), and a +potential audience of 15 million in more than 50 countries, providing +information via the WWW is becoming an extremely attractive proposition. + +\section{\LaTeX\ to HTML Conversion: Why?} + +HTML is quite a simple markup language to learn and use. It allows basic +formatting commands, bulleted lists, ``inlined'' images, and hypertext +links to other documents, multimedia sources, internet services or +computer programs. But despite (and +because of) its simplicity it has created a few headaches for +information providers: + +\begin{itemize} +\item there are no intuitive authoring tools (yet); +\item yet another hypertext language has to be learned; +\item existing documents available in other formats have to be reprocessed; +\item hypertext document ``webs'' are difficult to maintain; +\item it is difficult or impossible to create highly formatted +documents in HTML. +\end{itemize} + +\latextohtml can be used in order to address to a large degree these +problems. The authoring problem simply disappears, existing documents +can be reused immediately and a complex web of interlinked documents +can be generated from a single source document. The automatic +inclusion of formatted information such as tables or mathematical +equations as inlined images also bypasses another serious problem with +HTML. An additional benefit is that the paper-based version of a +document can also be obtained from the same source. + +The utility of a conversion tool like \latextohtml can be seen from +the variety of contexts in which it has been applied. Some examples +are listed below. +\begin{itemize} +\item Electronic books (e.g.\ that produced by the Computational + Science Education + Project\footnote{http://compsci.cas.vanderbilt.edu/csep.html} which + is sponsored by the US Department of Energy. This is one of the most + complex documents currently available via the WWW.). +\item General reports (e.g.\ the annual report of the Institute of + Astronomy at Cambridge\footnote{ + http://cast0.ast.cam.ac.uk/sub\-$\_$dir/cambridge/annual\-$\_$report/annual$\_$report.html}). +\item User +manuals\footnote{http://cs.indiana.edu:80/elisp/w3/docs.html}. +\item System + documentation\footnote{http://archie.ac.il:8001/papers/papers.html}. +\item Scientific papers such as those on the MIT Transit + Project\footnote{http://www.ai.mit.edu/projects/transit/tn-cat.html}. +\item Electronic journals (e.g.\ Complexity + International\footnote{http://life.anu.edu.au/ci/ci.html} --- a new + Australian electronic journal). +\end{itemize} +\section{\LaTeX\ to HTML conversion: How?} +The basic conversion process relies on the ability to distinguish +between the {\em structure}, the {\em content} and the {\em +formatting} information in a \LaTeX\ document. + +On the basis of sectioning information, a document is broken into +separate parts and an iconic navigation mechanism is constructed in +HTML which reflects this structure and allows a user to ``jump'' +between different parts. The cross-references, citations, footnotes, +the table of contents and the lists of figures and tables are also +translated into hypertext links. Formatting information which has +equivalent ``tags'' in HTML (lists, quotes, paragraph breaks, type +styles, etc.) is also converted appropriately. + +Although in most cases the loss of some formatting information (e.g. +page margins or line widths) is harmless, there are occasions where +the format has meaning e.g.\ when dealing with tables or user defined +environments. Another problem is the replication of the mathematical +equations which must retain both their precise format as well as any +of the predefined special mathematical symbols. + +The innovative solution in such cases relies on the ability of HTML +browsers to display inlined images inside the main text. Any part of a +\LaTeX\ document for which it is not obvious how it should be +translated directly into HTML is extracted from the main document and +then placed on a pipeline which converts it into an image. Each image +is then placed at the correct position in the final HTML document. +Special care is taken to preserve contextual information that may +affect the contents of each image (counter values, labels, references, +active style files etc). Some examples of converted documents can be +seen in Figure \ref{fig:mosaic}. + +\myfig{mosaic}{A converted document displayed using Mosaic} + + +\section{Hypermedia Extensions to \LaTeX} +Apart from the obvious hypertext links within a \LaTeX\ document (e.g. +navigation between sections, cross-references and citations) it is +also possible to take full advantage of the HTML links to arbitrary +multimedia sources (e.g.\ audio or video), electronic forms, and other +remote documents or internet services. + +This can be done with some new commands defined in a separate style +file ({\tt html.sty}) which are processed in a special way by the +\latextohtml translator. This style file defines commands for +embedding external hypertext links, for extending the basic {\tt + \verb#\#ref-\verb#\#label} mechanism to operate between remote +documents, and specifying that some text should only appear in the +paper-based version or only in the HTML document. In most cases these +commands have no effect when processed in the conventional way. + +Another command allows the inclusion of arbitrary HTML markup +directly in a \LaTeX\ document. This can be used to take advantage +of new HTML facilities as soon as they become available (HTML is +currently evolving towards a new specification called HTML+). +A particularly +good use of this feature is in the creation of interactive +electronic forms from within a \LaTeX\ document. + +\section{Concluding Remarks} +Conversion tools like \latextohtml provide an easy migration path +from familiar concepts towards authoring complex and format-rich +hypermedia documents. In this way, familiarity with a system +like \LaTeX\ makes it possible to contribute to and benefit from +a rapidly expanding global hypermedia network. + +\bibliographystyle{plain} +\begin{thebibliography}{1} + +\bibitem{tbl:www} +T.~Berners-Lee, R.~Cailliau, J.~Groff, and B.~Pollerman. +\newblock Worldwide web: The information universe. +\newblock {\em Electronic Networking: Research, Application and Policy}, (1), + 1992. + +\bibitem{levy:www} +Joe Levy. +\newblock The world in a web. +\newblock {\em {\it The} Guardian}, page~19, November 11 1993. + +\bibitem{vern:www} +Vern Paxson. +\newblock Growth trends in wide-area {TCP} connections. +\newblock {\em IEEE Network}, To Appear 1993. +\newblock Available at ftp://ftp.ee.lbl.gov/WAN-TCP-growth-trends.revised.ps.Z. + +\end{thebibliography} + +\appendix + +\section{Further Information} +\latextohtml is written in Perl and requires freely available +software. \htmladdnormallink{More information on how to get, install + and use it is available via the + WWW}{http://cbl.leeds.ac.uk/nikos/\-tex2html/doc/latex2html/\-latex2html.html} +or using anonymous ftp from ftp.tex.ac.uk in +pub/archive/support/latex2html. A new release is planned for early +December 1993. + +Several computers on the Internet have public access World Wide Web +clients accessible by telnet e.g.\ \\ \bull telnet info.cern.ch (direct +connection --- no username or password required) \\ \bull telnet +ukanaix.cc.ukans.edu (``Lynx'' requires a vt100 terminal. Log in as +www.) + +Information on World Wide Web is also available via anonymous ftp from +{\tt ftp.germany.eu.net} in {\tt pub/infosystems/www}. The Mosaic clients are +in the directory {\tt /pub/infosystems/www/ncsa/Web}. + +\end{article} + + + -- cgit v1.2.3