path: root/doc/starting.doc

/******************************************************************************
 *
 * 
 *
 * Copyright (C) 1997-2008 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.
 *
 * Documents produced by Doxygen are derivative works derived from the
 * input used in their production; they are not affected by this license.
 *
 */
/*! \page starting Getting started

The executable \c doxygen is the main program that parses the sources and 
generates the documentation. See section \ref doxygen_usage for more
detailed usage information.

The executable \c doxytag is only needed if you want to generate references 
to external documentation (i.e. documentation that was generated by doxygen) 
for which you do not have the sources. See section \ref doxytag_usage 
for more detailed usage information.

Optionally, the executable \c doxywizard can be used, which is a 
\ref doxywizard_usage "graphical front-end" for editing the configuration file 
that is used by doxygen and for running doxygen in a graphical environment.
For Mac OS X doxywizard will be started by clicking on the Doxygen application
icon.

The following figure shows the relation between the tools and the flow
of information between them (it looks complex but that's only because it
tries to be complete):

\image html infoflow.gif "Doxygen information flow" 
\image latex infoflow.eps "Doxygen information flow" width=14cm

\section step1 Step 1: Creating a configuration file

Doxygen uses a configuration file to determine all of its settings.
Each project should get its own configuration file. A project can consist
of a single source file, but can also be an entire source tree that is 
recursively scanned.

To simplify the creation of a configuration file, doxygen can create a 
template configuration file for you. To do this call \c doxygen 
from the command line with the \c -g option:
\verbatim
doxygen -g <config-file>
\endverbatim

where \<config-file\> is the name of the configuration file. If you omit
the file name, a file named \c Doxyfile will be created. If a file with the
name \<config-file\> already exists, doxygen will rename it to 
\<config-file\>.bak before generating the configuration template.
If you use <code>-</code> (i.e. the minus sign) as the file name then 
doxygen will try to read the configuration file from standard 
input (<code>stdin</code>), which can be useful for scripting.

The configuration file has a format that is similar to that of a (simple) 
Makefile. It consists of a number of assignments (tags) of the form:

<tt>TAGNAME = VALUE</tt> or <br>
<tt>TAGNAME = VALUE1 VALUE2 ... </tt><br>

You can probably leave the values of most tags in a generated template 
configuration file to their default value.  See section \ref config for 
more details about the configuration file. 

If you do not wish to edit the config file with a text editor, you should 
have a look at \ref doxywizard_usage "doxywizard", which is a GUI 
front-end that can create, read and write doxygen configuration files, 
and allows setting configuration options by entering them via dialogs.

For a small project consisting of a few C and/or C++ source 
and header files, you can leave
\ref cfg_input "INPUT" tag empty and doxygen will search for sources in
the current directory. 

If you have a larger project consisting of a source directory or tree 
you should assign the root directory or 
directories to the \ref cfg_input "INPUT" tag, and add one or more file 
patterns to the \ref cfg_file_patterns "FILE_PATTERNS" tag 
(for instance <code>*.cpp *.h</code>). Only files that match one of the 
patterns will be parsed (if the patterns are omitted a list of 
source extensions is used).
For recursive parsing of a source tree you must set 
the \ref cfg_recursive "RECURSIVE" tag to \c YES. To further fine-tune the 
list of files that is parsed the \ref cfg_exclude "EXCLUDE" and 
\ref cfg_exclude_patterns "EXCLUDE_PATTERNS" tags can be used.
To omit all \c test directories from a source tree for instance, one could use:
\verbatim EXCLUDE_PATTERNS = */test/* 
\endverbatim

Doxygen looks at the file's extension to determine how to parse a file.
If a file has an <code>.idl</code> or <code>.odl</code> extension it is 
treated as an IDL file. If it has a <code>.java</code> extension it is 
treated as a file written in Java. Files ending with <code>.cs</code> are 
treated as C# files and the <code>.py</code> extension selects the 
Python parser. Finally, files with the extensions <code>.php</code>, <code>.php4</code>,
<code>.inc</code> or <code>.phtml</code> are treated as PHP sources.
Any other extension is parsed as if it is a C/C++ file, where files that
end with <code>.m</code> are treated as Objective-C source files.

\anchor extract_all
If you start using doxygen for an existing project (thus without any 
documentation that doxygen is aware of), you can still get an idea of
what the structure is and how the documented result would look like. 
To do so, you must set 
the \ref cfg_extract_all "EXTRACT_ALL" tag in the configuration file 
to \c YES. Then, doxygen will pretend everything in your sources is documented. 
Please note that as a consequence warnings about undocumented members 
will not be generated as long as \ref cfg_extract_all "EXTRACT_ALL" is 
set to \c YES.

To analyse an existing piece of software it is useful to cross-reference 
a (documented) entity with its definition in the source files. Doxygen will
generate such cross-references if you set 
the \ref cfg_source_browser "SOURCE_BROWSER" tag to \c YES.  
It can also include the sources directly into the documentation by setting
\ref cfg_inline_sources "INLINE_SOURCES" to \c YES (this can be handy for 
code reviews for instance).

\section step2 Step 2: Running doxygen

To generate the documentation you can now enter:
\verbatim
doxygen <config-file>
\endverbatim

Depending on your settings doxygen will create \c html, \c rtf, 
\c latex, \c xml and/or \c man directories inside the output directory. 
As the names suggest these directories contain the
generated documentation in HTML, RTF, \f$\mbox{\LaTeX}\f$, XML and 
Unix-Man page format.

The default output directory is the directory in which \c doxygen
is started. The root directory to which the output is written can be changed 
using the \ref cfg_output_directory "OUTPUT_DIRECTORY". The format specific
directory within the output directory can be selected using the
\ref cfg_html_output "HTML_OUTPUT", \ref cfg_rtf_output "RTF_OUTPUT",
\ref cfg_latex_output "LATEX_OUTPUT", \ref cfg_xml_output "XML_OUTPUT",
and \ref cfg_man_output "MAN_OUTPUT" 
tags of the configuration file. If the output directory does not exist, 
\c doxygen will try to create it for you (but it will \e not try to create
a whole path recursively, like <code>mkdir -p</code> does). 

\subsection html_out HTML output
\addindex browser
The generated HTML documentation can be viewed by pointing a HTML browser
to the \c index.html file in the \c html directory. For the best results
a browser that supports cascading style sheets (CSS) should be used
(I'm using Mozilla, Safari, Konqueror, and sometimes IE6 to test the 
generated output). 

Some of the features the HTML section (such as 
\ref cfg_generate_treeview "GENERATE_TREEVIEW") require a browser that
supports DHTML and Javascript. 

If you plan to use the search engine (see 
\ref cfg_searchengine "SEARCHENGINE"), you should view the HTML output 
via a PHP-enabled web server (e.g. apache with the PHP module installed).

\subsection latex_out LaTeX output
\addindex LaTeX
The generated \f$\mbox{\LaTeX}\f$ documentation must first be compiled by 
a \f$\mbox{\LaTeX}\f$ compiler (I use a recent teTeX distribution). 
To simplify the process of compiling the generated
documentation, \c doxygen writes a \c Makefile into the \c latex directory. 

The contents and targets in the \c Makefile depend on the setting of
\ref cfg_use_pdflatex "USE_PDFLATEX". If it is disabled (set to \c NO), then
typing \c make in the \c latex directory a dvi file called \c refman.dvi
will be generated. This file can then be viewed using \c xdvi or 
converted into a PostScript file \c refman.ps by 
typing <code>make ps</code> (this requires <code>dvips</code>).  

To put 2 pages on one physical page use <code>make ps_2on1</code> instead.
The resulting PostScript file can be send to a PostScript
printer. If you do not have a PostScript printer, you can try to use 
ghostscript to convert PostScript into something your printer understands.

Conversion to PDF is also possible if you have installed the ghostscript
interpreter; just type <code>make pdf</code> (or <code>make pdf_2on1</code>). 

To get the best results for PDF output you should set 
the \ref cfg_pdf_hyperlinks "PDF_HYPERLINKS" 
and \ref cfg_use_pdflatex "USE_PDFLATEX" tags to \c YES. 
In this case the \c Makefile will only contain a target to build 
\c refman.pdf directly.

\subsection rtf_out RTF output
\addindex RTF
Doxygen combines the RTF output to a single file called refman.rtf. This
file is optimized for importing into the Microsoft Word. Certain information
is encoded using field. To show the actual value you need to 
select all (Edit - select all) and then toggle fields (right click and select
the option from the drop down menu).

\subsection xml_out XML output
\addindex XML
The XML output consists of a structured "dump" of the information gathered 
by doxygen. Each compound (class/namespace/file/...) has its own XML file 
and there is also an index file called index.xml. 

A file called combine.xslt
XSLT script is also generated and can be used to combine all XML files 
into a single file. 

Doxygen also generates two XML schema files index.xsd
(for the index file) and compound.xsd (for the compound files).
This schema file describes the possible elements, their attributes and 
how they are structured, i.e. it the describes the grammar of the XML 
files and can be used for validation or to steer XSLT scripts.

In the addon/doxmlparser directory you can find a parser library for reading
the XML output produced by doxygen in an incremental way 
(see addon/doxmlparser/include/doxmlintf.h for the interface of the library)

\subsection man_out Man page output
The generated man pages can be viewed using the \c man program. You do need
to make sure the man directory is in the man path (see the \c MANPATH
environment variable). Note that there are some limitations to the 
capabilities of the man page format, so some information 
(like class diagrams, cross references and formulas) will be lost.

\section step3 Step 3: Documenting the sources

Although documenting the sources is presented as step 3, in a new project 
this should of course be step 1. Here I assume
you already have some code and you want doxygen to generate a nice document 
describing the API and maybe the internals as well.

If the \ref cfg_extract_all "EXTRACT_ALL" option is set to \c NO in the 
configuration file (the default), then doxygen will only generate 
documentation for \e documented members, files, classes and namespaces. So 
how do you document these? For members, classes and namespaces there are 
basically two options:
<ol>
<li>Place a \e special documentation block in front of the declaration or
    definition of the member, class or namespace. For file, class and namespace
    members it is also allowed to place the documention directly after the 
    member. See section \ref specialblock to learn more about special 
    documentation blocks.
<li>Place a special documentation block somewhere else (another file or 
    another location) \e and put a <em>structural command</em> in the 
    documentation block. A structural command links a documentation block 
    to a certain entity that can be documented (e.g. a member, class, 
    namespace or file). See section \ref structuralcommands to learn more 
    about structural commands.
</ol>
Files can only be documented using the second option, since there is
no way to put a documentation block before a file. Of course, file members 
(functions, variable, typedefs, defines) do not need an explicit 
structural command; just putting a special documentation block in front or 
behind them will do. 

The text inside a special documentation block is parsed
before it is written to the HTML and/or \f$\mbox{\LaTeX}\f$ output files.

\addindex parsing
During parsing the following steps take place:
<ul>
<li> The special commands inside the documentation are executed. See
     section \ref commands for an overview of all commands.
<li> If a line starts with some whitespace followed by one or more asterisks 
     (<tt>*</tt>) and then optionally more whitespace, 
     then all whitespace and asterisks are removed.
<li> All resulting blank lines are treated as a paragraph separators.
     This saves you from placing new-paragraph commands yourself 
     in order to make the generated documentation readable.
<li> Links are created for words corresponding to documented classes
     (unless the word is preceded by a \%; then the word will not be linked and
     the \% sign is removed). 
<li> Links to members are created when certain patterns are found in the
     text. See section \ref autolink
     for more information on how the automatic link generation works.
<li> HTML tags that are in the documentation are interpreted and converted 
     to \f$\mbox{\LaTeX}\f$ equivalents for the \f$\mbox{\LaTeX}\f$ output. 
     See section \ref htmlcmds for an overview of all supported HTML tags.
</ul>

\htmlonly
Go to the <a href="docblocks.html">next</a> section or return to the
 <a href="index.html">index</a>.
\endhtmlonly

*/