/******************************************************************************
 *
 * 
 *
 * Copyright (C) 1997-2000 by Dimitri van Heesch.
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation under the terms of the GNU General Public License is hereby 
 * granted. No representations are made about the suitability of this software 
 * for any purpose. It is provided "as is" without express or implied warranty.
 * See the GNU General Public License for more details.
 *
 * All output generated with Doxygen is not covered by this license.
 *
 */
/*! \page doxysearch_usage Doxysearch usage

Doxysearch is a small, fast and highly portable search engine that allows 
you to search for strings or words in the documentation generated by  
<a href="doxygen_usage.html">doxygen</a> or 
in the Qt documentation (see <a href="#searchqt">below</a>). 
Doxysearch must be run as a CGI binary. This implies the following:
<ul>
<li> There must be a HTTP daemon running on the system where you want to 
     install the documentation (the <em>target</em>)
<li> You must have permission to install and execute a CGI binary on the 
     target.
</ul>
Ask you system administrator or provider if you are unsure if this is possible.

In order to be able to search fast and efficient, doxysearch does not 
search the generated documentation directly. Instead, it uses an 
<em>index file</em>, that should be generated with 
<a href="doxytag_usage.html">doxytag</a>. The index file is extracted from 
the generated HTML files and contains all words and substrings of words 
present in the HTML files, in a compact form, together with their 
frequencies and links. Although I tried to store all information 
as compactly as possible, the size of the index is still quite large. 
Usually it is about the same size as the original HTML files.

I have tried to make the search engine highly portable, because it  
must run on the target system. As a result doxysearch does not require the 
Qt library. All that is required to build doxysearch is a C++ compiler. 
If you are using \c g++ for example, you can build the search engine manually, 
by typing:
\verbatim
  g++ doxysearch.cpp -o doxysearch
\endverbatim

<a name="se">
<h3>Generating the search engine</h3>
</a>

To include a search engine in the documentation generated by doxygen
follow these steps:
<ol>
<li>Generate a configuration file with 
    <a href="doxygen_usage.html">doxygen</a> using the 
    <code>-g</code> option, if you haven't done this already.

<li>Edit the search engine section (see section \ref config_search of
    the configuration file).
    Make sure the \c SEARCHENGINE tag is set to \c YES
    and that all paths are correct.

<li>Use <a href="doxygen_usage.html">doxygen</a> to generate the 
    documentation. Apart from the documentation, Doxygen will create the 
    following files:
    <ul>
    <li>A small shell script. the name of the script is determined by the
        \c CGI_NAME tag in the configuration file.
        The script is a small wrapper that calls \c doxysearch with
        the correct parameters. Using this script allows multiple 
        search engines for different projects to be present in one directory.
    <li>\c search.cfg: this file is a small configuration file 
    for the search engine. It contains two lines of text. The first line
    should be the absolute URL to the documentation. The second line should
    be the absolute URL to the CGI script. This information is taken from
    the configuration file.
    <li>\c search.gif: this is the image that is used for the search button.
    </ul>

    \par Note:
      On the Windows platform Unix shell scripts cannot be used. 
      In fact the HTTP daemon that I tried (apache for Windows) only 
      recognized <code>.cgi</code> files that were renamed 
      executables (so DOS batch files do not seem to work either). Therefore,
      on Windows a small C program will generated by doxygen.
      You should compile and link the program with your favourite
      compiler and change the extension of the executable from 
      <code>.exe</code> to <code>.cgi</code>.

<li>Copy (or move) the CGI script to the directory where the CGI binaries
    are located.
    This is usually a special directory on your system or in your
    home directory.
    Consult the manual of your HTTP daemon or your system administrator to
    find out, where this directory resides on your system.

<li>Goto the directory where the generated HTML files are located and run 
    doxytag as follows:
    <pre>doxytag -s search.idx</pre>
    This will create a search index with the name <code>search.idx</code>.
    Currently the index file <em>must</em> be called like this.

<li>Run <a href="installdox_usage.html">installdox</a> to replace
    any dummy links in the documentation with real links.

    \par Note: 
    When using a search engine this step is <em>required</em>
    even if no tag files are used. If tag files are used you must specify
    the correct options.

</ol>

<a name="searchqt">
<h3>Creating a search engine to search in the Qt documentation</h3>
</a>

Using <code>doxytag</code> and <code>doxysearch</code> it is possible to create a search engine for
the Qt documentation, without needing the sources!
This can be done by carefully following these steps:
<ol>
<li>Goto the html directory of the Qt-distribution:
    <pre>cd $QTDIR/html</pre>
<li>Generate the search index by typing:
    <pre>doxytag -s search.idx</pre>
    in the directory where the HTML files are located.
    This will parse all files and build a search index.
    Apart from the file <code>search.idx</code> two other files
    will be generated: <code>search.gif</code> and <code>search.cgi</code>

    \par Note: 
       Doxytag requires quite a large amount of memory to
       generate the search index (about 30 Mb on my Linux box)!
       The resulting index file requires about 3 Mb space on your disk.

<li>Edit the shell script <code>search.cgi</code> with a text editor.

    Fill in the absolute path to the <code>doxysearch</code> binary after 
    the <code>DOXYSEARCH=</code> tag.
    On my system this becomes:
    <pre>DOXYSEARCH=/usr/local/bin/doxysearch</pre>

    Fill in the absolute path to the qt documentation after the
    <code>DOXYPATH=</code> tag.
    On my system this becomes:
    <pre>DOXYPATH=/usr/local/qt/html</pre>
<li>
    CGI binaries are usually located in a special directory.
    Consult the manual of your HTTP daemon or your system administrator to
    find out, where this directory resides on your system.
    Copy (or move) the <code>search.cgi</code> script to this directory.
    If needed you may change the name of the script.
    On my system, this becomes:
    <pre>cp search.cgi /usr/local/lib/httpd/cgi-bin/</pre>

<li>Create a text-file with the name <code>search.cfg</code>.
    On the first line, you must put the <em>absolute</em> URL to the Qt 
    documentation.
    Since, I only use the search engine on my own standalone system, I use
    the <code>file:</code> protocol. 
    On the second line, you must put the <em>absolute</em> URL to the
    cgi script.
    On my system the resulting file looks like this:
\verbatim
file:///usr/local/qt/html
http://blizzard/cgi-bin/search.cgi
\endverbatim

<li>Add a link to the search engine in the Qt documentation.
    On my system, I have put a line 
\verbatim
<li><a href="http://blizzard/cgi-bin/search.cgi">Search the documentation<a>
\endverbatim
    in the additional information section of the <code>index.html</code> file.
<li>Start your favourite web browser and click on the link.
    If everything is ok, you should get a page where you can enter 
    search terms.
</ol>

*/