repos_ecs/其他2015后/日志库/log4c-1.2.4/doc/main.doc.in

/**
@mainpage Log4c : Logging for C Library

@htmlonly
<center>
<a href="#summary">Summary</a>
<a href="#requirements">Requirements</a>
<a href="#installation">Installation</a>
<a href="#config">Configuration</a>
<a href="#custom">Customization</a>
<a href="#thanks">Thanks</a>
<a href="#copyright">Copyright</a>
</center>
@endhtmlonly

@section summary Summary

Log4c is a library of C for flexible logging to files, syslog and other
destinations. It is modeled after the Log for Java library
(http://jakarta.apache.org/log4j/), staying as close to their API as is
reasonable. Here is a <a href="http://logging.apache.org/log4j/1.2/manual.html">short
introduction</a> to Log4j which describes the API, and design rationale.

Mark Mendel started a parallel log4c projet with a different
philosophy. The design is macro oriented, so much lighter and faster
which perfect for kernel development.

Log4c is also available from SourceForge
(http://www.sourceforge.net/projects/log4c/). This is work in progress.

@section requirements Requirements
 
@subsection platforms Platforms

log4c was successfully compiled and run on the following platforms:

@li HP-UX release 11.00
@li Tru 64 release 4.0F and 5.1
@li Red Hat Linux Intel release 7.x, 8, 9
@li Red Hat Enterprise Linux 3, 4
@li Solaris Intel release 8, 9, 10
@li FreeBSD 6.1-RELEASE
@li AIX 5.3 (with xlc compiler)
@li Mac OS X
@li Windows X
@li ...and other Linux distributions

log4c should compile and run on the following platforms:

@li The BSD family
@li MS Windows

@subsection software Software
 
The following software is needed to generate log4c:

@li <a href="http://gcc.gnu.org">GCC</a> 3.0.1+, to generate log4c,
but hopefully not to use it. 
@li <a href="http://www.stack.nl/~dimitri/doxygen/index.html">doxygen</a>
1.2.13+, a documentation system for C/C++ needed to generate the
documentation.
@li <a href="http://www.graphviz.org/">graphviz</a>, the AT&T Graph
Visualization Tools also needed to generate the documentation.

For the moment, log4c uses specific GCC extensions, like @c __attribute__,
so you will need GCC to compile it. This will probably change one day. 

@section installation Installation
 
@subsection installation_tarballs Building from source tarballs

on SourceForge:
@li <a href="http://prdownloads.sourceforge.net/log4c/log4c-@VERSION@.tar.gz">log4c-@VERSION@.tar.gz</a>

The log4c package uses the GNU autotools compilation and installation
framework. The following commands should build log4c on the supported
platforms:

@code

$ gzip -dc log4c-@VERSION@.tar.gz | tar tvf -
$ cd log4c-@VERSION@/
$ ./configure --prefix=/path/of/installation
$ make
$ make install

@endcode

Checkout the @c INSTALL file for installation and the generated doxygen
documentation for more information.

@section config Configuration

@subsection conf_files Configuration files

log4c searches the following files to load its configuration:

@li @c ${LOG4C_RCPATH}/log4crc
@li @c ${HOME}/.log4crc
@li @c ./log4crc

The environment variable @c LOG4C_RCPATH holds the prefix used for
installation.

@subsection conf_syntax Configuration syntax

The @c log4crc configuration file uses an XML syntax. The root element is
@c <log4c> and it can be used to control the configuration file version
interface with the attribute @c "version". The following 4 elements are
supported: @c <config>, @c <category>, @c <appender> and @c <layout>.

@li The @c <config> element controls the global log4c configuration. It has
3 sub elements. The @c <nocleanup> flag inhibits the log4c destructors
routines. The @c <bufsize> element sets the buffer size used to format
log4c_logging_event_t objects. If is set to 0, the allocation is
dynamic (the @c <debug> element is currently unused).

@li The @c <category> element has 3 possible attributes: the category @c
"name", the category @c "priority" and the category @c "appender". Future
versions will handle multiple appenders per category.

@li The @c <appender> element has 3 possible attributes: the appender @c
"name", the appender @c "type", and the appender @c "layout".

@li The @c <layout> element has 2 possible attributes: the layout @c "name" and
the layout @c "type".

Here's the @c log4crc configuration file example:

@include log4crc.sample

This initial version of the log4c configuration file syntax is quite
different from log4j. XML seemed the best choice to keep the log4j
configuration power in a C API.

@subsection env Environment variables

@li @c LOG4C_RCPATH holds the path to the main @c log4crc configuration
file
@li @c LOG4C_PRIORITY holds the @c "root" category priority
@li @c LOG4C_APPENDER holds the @c "root" category appender

@section custom Customization

This section will, one day, briefly describe how to define custom appenders
and custom layouts. Be patient or checkout the source.

@section thanks Thanks

Mark Mendel for his work on a previous version of log4c.

This project would not have existed without Ceki Gulcu,
the creator and maintainer of <a
href="http://jakarta.apache.org/log4j">Log4j</a>, nor without
Bastiaan Bakker, who initiated me with <a
href="http://log4cpp.sourceforge.net/">Log4Cpp</a>.

Many thanks to 

@li Joel Schaubert for many contributions
@li Robert Byrne for Windows port and also many contributions
@li Olger Warnier for the Mac OS X port 
@li Jeff Smith for writing a primer on <a
href="http://jefficus.usask.ca/article.php?story=20040613140849924">how
to use Log4c effectively</a>

@section copyright Copyright

All software in this package is Copyright (C) 2003-2004 Meiosys
http://www.meiosys.com and Cedric Le Goater and is
distributed under the <a
href="http://www.gnu.org/licenses/lgpl.html">LGPL</a> License. See the @c
COPYING file for full legal details.

*/