\documentclass{ictlab}

\RCS $Revision: 1.2 $

\usepackage{alltt,key,amssymb,url}

\ifx\pdftexversion\undefined \else
  \usepackage[pdfpagemode=None,pdfauthor={Nick Urbanik}]{hyperref}
\fi

\newcommand*{\labTitle}{Setting up Netscape}
\renewcommand*{\subject}{Operating Systems and Systems Integration}

\begin{document}

\section{Aim}
\label{sec:aim}

Here we set up Netscape so that when we click on a hyperlink to a
\acro{PDF} (``Acrobat'') file, the program \texttt{xpdf} will start up
to read it.  We also configure the \emph{proxy configuration}, set the
font size bigger, and make \url{http://ictlab.tyict.vtc.edu.hk/ossi/}
the default home page.

\section{Background}
\label{sec:background}

My dictionary says a \emph{proxy} is an agent given responsibility to
act for another.  A \emph{proxy server} is a network server that sits
on the border of the network.  It works as a ``go-between'' between a
web browser (for example, in the Campus), and a web server, out on the
Internet\@.  It works like this:
\begin{itemize}
\item request from web browser goes to proxy
\item If proxy has a recent copy of the web page in its \emph{cache},
  it sends the page straight to the web browser,
\item If the proxy has no copy,
  \begin{itemize}
  \item It asks the web server for a copy
  \item It stores the page in its cache
  \item It sends the page to the web browser.
  \end{itemize}
\end{itemize}
The proxy server has two purposes:
\begin{enumerate}
\item It speeds up access by web clients to popular web pages by
  caching them locally

\item It increases security, since the gateway to the Internet can be
  better controlled; the proxy is a component in the firewall, which
  filters dangerous traffic to reduce the risk of bad crackers out on
  the Internet breaking into important computers in the College.
\end{enumerate}


\section{Procedure}
\label{sec:procedure}


\subsection{Setting up Netscape to start \texttt{xpdf} whenever you
  click on a hyperlink to a PDF file}
\label{sec:xpdf-setup}

\textbf{Note:} I suggest that you use the acrobat reader instead.  The
instructions for this are given at
\url{http://intra.tyict.vtc.edu.hk/ossi/lab/install-acrobat/install-acrobat.pdf}.
Please do that instead.

\begin{enumerate}
\item Start Linux

\item start Netscape by clicking once on the Netscape icon in the
  panel at the bottom of the screen.
  %\includegraphics{netscape-icon}
  
\item From the \textsf{Edit} menu select \textsf{Preferences}, then
  click on that $\blacktriangleright$ triangle next to
  \textsf{Navigator} to turn it into a $\blacktriangledown$ triangle,
  and select \textsf{Applications}\@.

\item Scroll through the list of applications until you see the
  \textsf{Description} \textsf{Portable Document Format}\@.  Select
  that line, and click on the \textsf{Edit\ldots} button.

\item Click on the \textsf{Application} button.

\item Enter \texttt{/usr/bin/xpdf \%s} in the \textsf{Application} field.
  
\item The screen will look something like
  figure~\vref{fig:xpdf-setup}.
  \begin{figure}[htb]
    \begin{minipage}[c]{0.28\textwidth}
      \caption{Setting up Netscape to run xpdf when you click on a
        hyperlink to a PDF file.}
     \label{fig:xpdf-setup}
    \end{minipage}%
    \hspace*{0.04\textwidth}%
    \begin{minipage}[c]{0.68\textwidth}
      \includegraphics[width=\textwidth]{xpdf-setup}
    \end{minipage}
  \end{figure}
\end{enumerate}


\subsection{Entering the proxy setting}
\label{sec:proxy}

Unless the proxy is set, you will only be able to connect to other web
servers behind the College firewall.  To set it:
\begin{enumerate}
\item From the \textsf{Edit} menu select \textsf{Preferences}, then
  click on that $\blacktriangleright$ triangle next to
  \textsf{Advanced} to turn it into a $\blacktriangledown$ triangle,
  and select \textsf{Proxies}\@.

  \begin{figure}[htb]
    \begin{minipage}[c]{0.28\textwidth}
      \caption{The automatic proxy configuration in Netscape.}
     \label{fig:proxy-setting}
    \end{minipage}%
    \hspace*{0.04\textwidth}%
    \begin{minipage}[c]{0.68\textwidth}
      \includegraphics[width=\textwidth]{netscape-proxy-setting}
    \end{minipage}
  \end{figure}
\item Click on the Automatic Proxy Configuration button, and in the
  field there type \url{http://tyintra.vtc.edu.hk/proxy.proxy}, as in
  figure~\vref{fig:proxy-setting}.
  \begin{explanation}
    This will download a Javascript file (you will find it later,
    after you use Netscape, in the file
    $\sim$\texttt{/.netscape\allowbreak/proxyconf}.  The Javascript
    selects a suitable proxy depending on what destination you want to
    connect to, and where you are.
  \end{explanation}

\item Click on the \textsf{Reload} button.

\item Click on \textsf{OK}.

\subsection{Setting the Caching policy}
\label{sec:caching}

The web browser stores web pages that you download on the hard disk in
the \emph{web cache}.  When you visit the page a second time, you will
see the copy rather than wait for the browser to download the page a
second time.  This speeds things up.  There is a problem, however,
when the content changes between the first time you read the page to
the second time.  Normally you will not see the changed version, only
the first version.

The teaching material at our subject web site changes often.  To make
sure that you are getting the latest version, please do the following:
  \begin{figure}[htb]
    \begin{minipage}[c]{0.28\textwidth}
      \caption{The cache setting in Netscape.  This is also important
        for Web application developers.  For people like us (system
        administrators and web site developers), this is nearly always
        the right choice.}
     \label{fig:netscape-cache-setting}
    \end{minipage}%
    \hspace*{0.04\textwidth}%
    \begin{minipage}[c]{0.68\textwidth}
      \includegraphics[width=\textwidth]{netscape-cache-setting}
    \end{minipage}
  \end{figure}
\begin{enumerate}
\item From the \textsf{Edit} menu select \textsf{Preferences}.


\item click on the $\blacktriangleright$ triangle next to
  \textsf{Advanced} to turn it into a $\blacktriangledown$ triangle,
  and select \textsf{Cache}\@.

\item Select ``\textsf{Every time}, instead of ``\textsf{Once per
    session}'', as in figure~\vref{fig:netscape-cache-setting}.

\item Click on the \textsf{OK} button.
\end{enumerate}
Note that there is a slight performance penalty, but it is worth it to
reduce the confusion with rapidly changing web sites, and for those who
are developing them.

\subsection{Setting home page, larger font}
\label{sec:misc}

There are two other settings that are convenient for us using Netscape
here; one is to select the home page for our own web server:
\begin{enumerate}
\item From the \textsf{Edit} menu select \textsf{Preferences}, then
  click on \textsf{Navigator}\@.

\item For the \textsf{Home page Location}, enter:
  \url{http://ictlab.tyict.vtc.edu.hk/ossi/}

\item To make the default font larger, 
  click on the $\blacktriangleright$ triangle next to
  \textsf{Appearance} to turn it into a $\blacktriangledown$ triangle,
  and select \textsf{Fonts}\@.

\item Change the \textsf{Size} to 18.

\item Click \textsf{OK}, and you are ready to use Netscape to read the
  teaching material on our web site.

\end{enumerate}
\end{enumerate}
\end{document}