embedaddon/confuse/doc/tutorial-html/ar01s08.html - view

File: [ELWIX - Embedded LightWeight unIX -] / embedaddon / confuse / doc / tutorial-html / ar01s08.html
Revision 1.1.1.2 (vendor branch): download - view: text, annotated - select for diffs - revision graph
Wed Mar 17 00:49:17 2021 UTC (3 years, 4 months ago) by misho
Branches: confuse, MAIN
CVS tags: v3_3, HEAD

confuse 3.3

<?xml version="1.0" encoding="UTF-8" standalone="no"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>8. Functions</title><link rel="stylesheet" type="text/css" href="tutorial.css" /><meta name="generator" content="DocBook XSL Stylesheets V1.79.1" /><link rel="home" href="index.html" title="libConfuse tutorial" /><link rel="up" href="index.html" title="libConfuse tutorial" /><link rel="prev" href="ar01s07.html" title="7. Value parsing callback" /><link rel="next" href="ar01s09.html" title="9. Saving configuration files" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">8. Functions</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ar01s07.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="ar01s09.html">Next</a></td></tr></table><hr /></div><div class="sect1"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="idm138"></a>8. Functions</h2></div></div></div><p> libConfuse supports functions to parse options that does not fit well in the general syntax. Functions can be called with a variable number of arguments. No data from the function or any arguments are stored by libConfuse after the function has run. It is up to the caller to process and/or save the data. </p><p> A function is defined with a <code class="function">CFG_FUNC</code> macro. It takes two arguments: the name of the function and a function callback. The callback is defined as: </p><pre class="programlisting"> typedef int (*cfg_func_t)(cfg_t *cfg, cfg_opt_t *opt, int argc, const char **argv); </pre><p> </p><div class="sect2"><div class="titlepage"><div><div><h3 class="title"><a id="idm145"></a>8.1. Predefined functions</h3></div></div></div><p> Currently there is only one pre-defined function: <code class="function">cfg_include()</code>. This function includes another configuration file. Configuration data is immediately read from the included file, and is returned to the position right after the include() statement upon end of file. </p><p> To use this function, include a <code class="function">CFG_FUNC()</code> entry in your options: </p><pre class="programlisting"> cfg_opt_t opts[] = { CFG_FUNC("include", cfg_include), CFG_END() }; </pre><p> In the configuration file, it is used in the following way: </p><pre class="programlisting"> include("included.conf") </pre></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ar01s07.html">Prev</a> </td><td width="20%" align="center"> </td><td width="40%" align="right"> <a accesskey="n" href="ar01s09.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">7. Value parsing callback </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> 9. Saving configuration files</td></tr></table></div></body></html>