Google Git
Sign in
nest-open-source / nest-cam / 4320010 / glib / f6dccbe12024995c576bb85b2ad596af2833d2bd / . / glib / docs / reference / glib / html / glib-Dynamic-Loading-of-Modules.html
blob: 14273c8278b5546c79b7486a5452e3792759e78c [file] [log] [blame]
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Dynamic Loading of Modules: GLib Reference Manual</title>
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
<link rel="home" href="index.html" title="GLib Reference Manual">
<link rel="up" href="glib-core.html" title="GLib Core Application Support">
<link rel="prev" href="glib-Asynchronous-Queues.html" title="Asynchronous Queues">
<link rel="next" href="glib-Memory-Allocation.html" title="Memory Allocation">
<meta name="generator" content="GTK-Doc V1.25.1 (XML mode)">
<link rel="stylesheet" href="style.css" type="text/css">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table class="navigation" id="top" width="100%" summary="Navigation header" cellpadding="2" cellspacing="5"><tr valign="middle">
<td width="100%" align="left" class="shortcuts">
<a href="#" class="shortcut">Top</a><span id="nav_description">  <span class="dim">|</span> 
<a href="#glib-Dynamic-Loading-of-Modules.description" class="shortcut">Description</a></span>
</td>
<td><a accesskey="h" href="index.html"><img src="home.png" width="16" height="16" border="0" alt="Home"></a></td>
<td><a accesskey="u" href="glib-core.html"><img src="up.png" width="16" height="16" border="0" alt="Up"></a></td>
<td><a accesskey="p" href="glib-Asynchronous-Queues.html"><img src="left.png" width="16" height="16" border="0" alt="Prev"></a></td>
<td><a accesskey="n" href="glib-Memory-Allocation.html"><img src="right.png" width="16" height="16" border="0" alt="Next"></a></td>
</tr></table>
<div class="refentry">
<a name="glib-Dynamic-Loading-of-Modules"></a><div class="titlepage"></div>
<div class="refnamediv"><table width="100%"><tr>
<td valign="top">
<h2><span class="refentrytitle"><a name="glib-Dynamic-Loading-of-Modules.top_of_page"></a>Dynamic Loading of Modules</span></h2>
<p>Dynamic Loading of Modules — portable method for dynamically loading 'plug-ins'</p>
</td>
<td class="gallery_image" valign="top" align="right"></td>
</tr></table></div>
<div class="refsect1">
<a name="glib-Dynamic-Loading-of-Modules.functions"></a><h2>Functions</h2>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="functions_return">
<col class="functions_name">
</colgroup>
<tbody>
<tr>
<td class="function_type">
<a class="link" href="glib-Basic-Types.html#gboolean" title="gboolean"><span class="returnvalue">gboolean</span></a>
</td>
<td class="function_name">
<a class="link" href="glib-Dynamic-Loading-of-Modules.html#g-module-supported" title="g_module_supported ()">g_module_supported</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="returnvalue">gchar</span></a> *
</td>
<td class="function_name">
<a class="link" href="glib-Dynamic-Loading-of-Modules.html#g-module-build-path" title="g_module_build_path ()">g_module_build_path</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModule" title="GModule"><span class="returnvalue">GModule</span></a> *
</td>
<td class="function_name">
<a class="link" href="glib-Dynamic-Loading-of-Modules.html#g-module-open" title="g_module_open ()">g_module_open</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a class="link" href="glib-Basic-Types.html#gboolean" title="gboolean"><span class="returnvalue">gboolean</span></a>
</td>
<td class="function_name">
<a class="link" href="glib-Dynamic-Loading-of-Modules.html#g-module-symbol" title="g_module_symbol ()">g_module_symbol</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="returnvalue">gchar</span></a> *
</td>
<td class="function_name">
<a class="link" href="glib-Dynamic-Loading-of-Modules.html#g-module-name" title="g_module_name ()">g_module_name</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="glib-Dynamic-Loading-of-Modules.html#g-module-make-resident" title="g_module_make_resident ()">g_module_make_resident</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a class="link" href="glib-Basic-Types.html#gboolean" title="gboolean"><span class="returnvalue">gboolean</span></a>
</td>
<td class="function_name">
<a class="link" href="glib-Dynamic-Loading-of-Modules.html#g-module-close" title="g_module_close ()">g_module_close</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="returnvalue">gchar</span></a> *
</td>
<td class="function_name">
<a class="link" href="glib-Dynamic-Loading-of-Modules.html#g-module-error" title="g_module_error ()">g_module_error</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="returnvalue">gchar</span></a> *
</td>
<td class="function_name">
<span class="c_punctuation">(</span><a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModuleCheckInit" title="GModuleCheckInit ()">*GModuleCheckInit</a><span class="c_punctuation">)</span> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<span class="c_punctuation">(</span><a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModuleUnload" title="GModuleUnload ()">*GModuleUnload</a><span class="c_punctuation">)</span> <span class="c_punctuation">()</span>
</td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect1">
<a name="glib-Dynamic-Loading-of-Modules.other"></a><h2>Types and Values</h2>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="name">
<col class="description">
</colgroup>
<tbody>
<tr>
<td class="datatype_keyword"> </td>
<td class="function_name"><a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModule" title="GModule">GModule</a></td>
</tr>
<tr>
<td class="datatype_keyword">enum</td>
<td class="function_name"><a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModuleFlags" title="enum GModuleFlags">GModuleFlags</a></td>
</tr>
<tr>
<td class="define_keyword">#define</td>
<td class="function_name"><a class="link" href="glib-Dynamic-Loading-of-Modules.html#G-MODULE-SUFFIX:CAPS" title="G_MODULE_SUFFIX">G_MODULE_SUFFIX</a></td>
</tr>
<tr>
<td class="define_keyword">#define</td>
<td class="function_name"><a class="link" href="glib-Dynamic-Loading-of-Modules.html#G-MODULE-EXPORT:CAPS" title="G_MODULE_EXPORT">G_MODULE_EXPORT</a></td>
</tr>
<tr>
<td class="define_keyword">#define</td>
<td class="function_name"><a class="link" href="glib-Dynamic-Loading-of-Modules.html#G-MODULE-IMPORT:CAPS" title="G_MODULE_IMPORT">G_MODULE_IMPORT</a></td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect1">
<a name="glib-Dynamic-Loading-of-Modules.includes"></a><h2>Includes</h2>
<pre class="synopsis">#include &lt;gmodule.h&gt;
</pre>
</div>
<div class="refsect1">
<a name="glib-Dynamic-Loading-of-Modules.description"></a><h2>Description</h2>
<p>These functions provide a portable way to dynamically load object files
(commonly known as 'plug-ins'). The current implementation supports all
systems that provide an implementation of <code class="function">dlopen()</code> (e.g. Linux/Sun), as
well as Windows platforms via DLLs.</p>
<p>A program which wants to use these functions must be linked to the
libraries output by the command <code class="literal">pkg-config --libs gmodule-2.0</code>.</p>
<p>To use them you must first determine whether dynamic loading
is supported on the platform by calling <a class="link" href="glib-Dynamic-Loading-of-Modules.html#g-module-supported" title="g_module_supported ()"><code class="function">g_module_supported()</code></a>.
If it is, you can open a module with <a class="link" href="glib-Dynamic-Loading-of-Modules.html#g-module-open" title="g_module_open ()"><code class="function">g_module_open()</code></a>,
find the module's symbols (e.g. function names) with <a class="link" href="glib-Dynamic-Loading-of-Modules.html#g-module-symbol" title="g_module_symbol ()"><code class="function">g_module_symbol()</code></a>,
and later close the module with <a class="link" href="glib-Dynamic-Loading-of-Modules.html#g-module-close" title="g_module_close ()"><code class="function">g_module_close()</code></a>.
<a class="link" href="glib-Dynamic-Loading-of-Modules.html#g-module-name" title="g_module_name ()"><code class="function">g_module_name()</code></a> will return the file name of a currently opened module.</p>
<p>If any of the above functions fail, the error status can be found with
<a class="link" href="glib-Dynamic-Loading-of-Modules.html#g-module-error" title="g_module_error ()"><code class="function">g_module_error()</code></a>.</p>
<p>The <a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModule" title="GModule"><span class="type">GModule</span></a> implementation features reference counting for opened modules,
and supports hook functions within a module which are called when the
module is loaded and unloaded (see <a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModuleCheckInit" title="GModuleCheckInit ()"><span class="type">GModuleCheckInit</span></a> and <a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModuleUnload" title="GModuleUnload ()"><span class="type">GModuleUnload</span></a>).</p>
<p>If your module introduces static data to common subsystems in the running
program, e.g. through calling
<code class="literal">g_quark_from_static_string ("my-module-stuff")</code>,
it must ensure that it is never unloaded, by calling <a class="link" href="glib-Dynamic-Loading-of-Modules.html#g-module-make-resident" title="g_module_make_resident ()"><code class="function">g_module_make_resident()</code></a>.</p>
<p>Example: Calling a function defined in a GModule</p>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42</pre></td>
<td class="listing_code"><pre class="programlisting"><span class="comment">// the function signature for 'say_hello'</span>
<span class="keyword">typedef</span><span class="normal"> </span><span class="type">void</span><span class="normal"> </span><span class="symbol">(*</span><span class="normal"> SayHelloFunc</span><span class="symbol">)</span><span class="normal"> </span><span class="symbol">(</span><span class="keyword">const</span><span class="normal"> </span><span class="type">char</span><span class="normal"> </span><span class="symbol">*</span><span class="normal">message</span><span class="symbol">);</span>
<span class="normal"><a href="glib-Basic-Types.html#gboolean">gboolean</a></span>
<span class="function">just_say_hello</span><span class="normal"> </span><span class="symbol">(</span><span class="keyword">const</span><span class="normal"> </span><span class="type">char</span><span class="normal"> </span><span class="symbol">*</span><span class="normal">filename</span><span class="symbol">,</span><span class="normal"> </span><span class="usertype">GError</span><span class="normal"> </span><span class="symbol">**</span><span class="normal">error</span><span class="symbol">)</span>
<span class="cbracket">{</span>
<span class="normal"> </span><span class="usertype">SayHelloFunc</span><span class="normal"> say_hello</span><span class="symbol">;</span>
<span class="normal"> </span><span class="usertype">GModule</span><span class="normal"> </span><span class="symbol">*</span><span class="normal">module</span><span class="symbol">;</span>
<span class="normal"> module </span><span class="symbol">=</span><span class="normal"> </span><span class="function"><a href="glib-Dynamic-Loading-of-Modules.html#g-module-open">g_module_open</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">filename</span><span class="symbol">,</span><span class="normal"> <a href="glib-Dynamic-Loading-of-Modules.html#G-MODULE-BIND-LAZY:CAPS">G_MODULE_BIND_LAZY</a></span><span class="symbol">);</span>
<span class="normal"> </span><span class="keyword">if</span><span class="normal"> </span><span class="symbol">(!</span><span class="normal">module</span><span class="symbol">)</span>
<span class="normal"> </span><span class="cbracket">{</span>
<span class="normal"> </span><span class="function"><a href="glib-Error-Reporting.html#g-set-error">g_set_error</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">error</span><span class="symbol">,</span><span class="normal"> FOO_ERROR</span><span class="symbol">,</span><span class="normal"> FOO_ERROR_BLAH</span><span class="symbol">,</span>
<span class="normal"> </span><span class="string">"%s"</span><span class="symbol">,</span><span class="normal"> </span><span class="function"><a href="glib-Dynamic-Loading-of-Modules.html#g-module-error">g_module_error</a></span><span class="normal"> </span><span class="symbol">());</span>
<span class="normal"> </span><span class="keyword">return</span><span class="normal"> <a href="glib-Standard-Macros.html#FALSE:CAPS">FALSE</a></span><span class="symbol">;</span>
<span class="normal"> </span><span class="cbracket">}</span>
<span class="normal"> </span><span class="keyword">if</span><span class="normal"> </span><span class="symbol">(!</span><span class="function"><a href="glib-Dynamic-Loading-of-Modules.html#g-module-symbol">g_module_symbol</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">module</span><span class="symbol">,</span><span class="normal"> </span><span class="string">"say_hello"</span><span class="symbol">,</span><span class="normal"> </span><span class="symbol">(</span><span class="normal"><a href="glib-Basic-Types.html#gpointer">gpointer</a> </span><span class="symbol">*)&amp;</span><span class="normal">say_hello</span><span class="symbol">))</span>
<span class="normal"> </span><span class="cbracket">{</span>
<span class="normal"> </span><span class="function"><a href="glib-Error-Reporting.html#g-set-error">g_set_error</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">error</span><span class="symbol">,</span><span class="normal"> SAY_ERROR</span><span class="symbol">,</span><span class="normal"> SAY_ERROR_OPEN</span><span class="symbol">,</span>
<span class="normal"> </span><span class="string">"%s: %s"</span><span class="symbol">,</span><span class="normal"> filename</span><span class="symbol">,</span><span class="normal"> </span><span class="function"><a href="glib-Dynamic-Loading-of-Modules.html#g-module-error">g_module_error</a></span><span class="normal"> </span><span class="symbol">());</span>
<span class="normal"> </span><span class="keyword">if</span><span class="normal"> </span><span class="symbol">(!</span><span class="function"><a href="glib-Dynamic-Loading-of-Modules.html#g-module-close">g_module_close</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">module</span><span class="symbol">))</span>
<span class="normal"> </span><span class="function"><a href="glib-Message-Logging.html#g-warning">g_warning</a></span><span class="normal"> </span><span class="symbol">(</span><span class="string">"%s: %s"</span><span class="symbol">,</span><span class="normal"> filename</span><span class="symbol">,</span><span class="normal"> </span><span class="function"><a href="glib-Dynamic-Loading-of-Modules.html#g-module-error">g_module_error</a></span><span class="normal"> </span><span class="symbol">());</span>
<span class="normal"> </span><span class="keyword">return</span><span class="normal"> <a href="glib-Standard-Macros.html#FALSE:CAPS">FALSE</a></span><span class="symbol">;</span>
<span class="normal"> </span><span class="cbracket">}</span>
<span class="normal"> </span><span class="keyword">if</span><span class="normal"> </span><span class="symbol">(</span><span class="normal">say_hello </span><span class="symbol">==</span><span class="normal"> <a href="glib-Standard-Macros.html#NULL:CAPS">NULL</a></span><span class="symbol">)</span>
<span class="normal"> </span><span class="cbracket">{</span>
<span class="normal"> </span><span class="function"><a href="glib-Error-Reporting.html#g-set-error">g_set_error</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">error</span><span class="symbol">,</span><span class="normal"> SAY_ERROR</span><span class="symbol">,</span><span class="normal"> SAY_ERROR_OPEN</span><span class="symbol">,</span>
<span class="normal"> </span><span class="string">"symbol say_hello is NULL"</span><span class="symbol">);</span>
<span class="normal"> </span><span class="keyword">if</span><span class="normal"> </span><span class="symbol">(!</span><span class="function"><a href="glib-Dynamic-Loading-of-Modules.html#g-module-close">g_module_close</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">module</span><span class="symbol">))</span>
<span class="normal"> </span><span class="function"><a href="glib-Message-Logging.html#g-warning">g_warning</a></span><span class="normal"> </span><span class="symbol">(</span><span class="string">"%s: %s"</span><span class="symbol">,</span><span class="normal"> filename</span><span class="symbol">,</span><span class="normal"> </span><span class="function"><a href="glib-Dynamic-Loading-of-Modules.html#g-module-error">g_module_error</a></span><span class="normal"> </span><span class="symbol">());</span>
<span class="normal"> </span><span class="keyword">return</span><span class="normal"> <a href="glib-Standard-Macros.html#FALSE:CAPS">FALSE</a></span><span class="symbol">;</span>
<span class="normal"> </span><span class="cbracket">}</span>
<span class="normal"> </span><span class="comment">// call our function in the module</span>
<span class="normal"> </span><span class="function">say_hello</span><span class="normal"> </span><span class="symbol">(</span><span class="string">"Hello world!"</span><span class="symbol">);</span>
<span class="normal"> </span><span class="keyword">if</span><span class="normal"> </span><span class="symbol">(!</span><span class="function"><a href="glib-Dynamic-Loading-of-Modules.html#g-module-close">g_module_close</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">module</span><span class="symbol">))</span>
<span class="normal"> </span><span class="function"><a href="glib-Message-Logging.html#g-warning">g_warning</a></span><span class="normal"> </span><span class="symbol">(</span><span class="string">"%s: %s"</span><span class="symbol">,</span><span class="normal"> filename</span><span class="symbol">,</span><span class="normal"> </span><span class="function"><a href="glib-Dynamic-Loading-of-Modules.html#g-module-error">g_module_error</a></span><span class="normal"> </span><span class="symbol">());</span>
<span class="normal"> </span><span class="keyword">return</span><span class="normal"> <a href="glib-Standard-Macros.html#TRUE:CAPS">TRUE</a></span><span class="symbol">;</span>
<span class="normal"> </span><span class="cbracket">}</span></pre></td>
</tr>
</tbody>
</table>
</div>
<p></p>
</div>
<div class="refsect1">
<a name="glib-Dynamic-Loading-of-Modules.functions_details"></a><h2>Functions</h2>
<div class="refsect2">
<a name="g-module-supported"></a><h3>g_module_supported ()</h3>
<pre class="programlisting"><a class="link" href="glib-Basic-Types.html#gboolean" title="gboolean"><span class="returnvalue">gboolean</span></a>
g_module_supported (<em class="parameter"><code><span class="type">void</span></code></em>);</pre>
<p>Checks if modules are supported on the current platform.</p>
<div class="refsect3">
<a name="g-module-supported.returns"></a><h4>Returns</h4>
<p> <a class="link" href="glib-Standard-Macros.html#TRUE:CAPS" title="TRUE"><code class="literal">TRUE</code></a> if modules are supported</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-module-build-path"></a><h3>g_module_build_path ()</h3>
<pre class="programlisting"><a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="returnvalue">gchar</span></a> *
g_module_build_path (<em class="parameter"><code>const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="type">gchar</span></a> *directory</code></em>,
<em class="parameter"><code>const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="type">gchar</span></a> *module_name</code></em>);</pre>
<p>A portable way to build the filename of a module. The platform-specific
prefix and suffix are added to the filename, if needed, and the result
is added to the directory, using the correct separator character.</p>
<p>The directory should specify the directory where the module can be found.
It can be <a class="link" href="glib-Standard-Macros.html#NULL:CAPS" title="NULL"><code class="literal">NULL</code></a> or an empty string to indicate that the module is in a
standard platform-specific directory, though this is not recommended
since the wrong module may be found.</p>
<p>For example, calling <a class="link" href="glib-Dynamic-Loading-of-Modules.html#g-module-build-path" title="g_module_build_path ()"><code class="function">g_module_build_path()</code></a> on a Linux system with a
<em class="parameter"><code>directory</code></em>
of <code class="literal">/lib</code> and a <em class="parameter"><code>module_name</code></em>
of "mylibrary" will return
<code class="literal">/lib/libmylibrary.so</code>. On a Windows system, using <code class="literal">\Windows</code> as the
directory it will return <code class="literal">\Windows\mylibrary.dll</code>.</p>
<div class="refsect3">
<a name="g-module-build-path.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>directory</p></td>
<td class="parameter_description"><p> the directory where the module is. This can be
<a class="link" href="glib-Standard-Macros.html#NULL:CAPS" title="NULL"><code class="literal">NULL</code></a> or the empty string to indicate that the standard platform-specific
directories will be used, though that is not recommended. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="NULL is OK, both for passing and for returning."><span class="acronym">allow-none</span></acronym>]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>module_name</p></td>
<td class="parameter_description"><p>the name of the module</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="g-module-build-path.returns"></a><h4>Returns</h4>
<p> the complete path of the module, including the standard library
prefix and suffix. This should be freed when no longer needed</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-module-open"></a><h3>g_module_open ()</h3>
<pre class="programlisting"><a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModule" title="GModule"><span class="returnvalue">GModule</span></a> *
g_module_open (<em class="parameter"><code>const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="type">gchar</span></a> *file_name</code></em>,
<em class="parameter"><code><a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModuleFlags" title="enum GModuleFlags"><span class="type">GModuleFlags</span></a> flags</code></em>);</pre>
<p>Opens a module. If the module has already been opened,
its reference count is incremented.</p>
<p>First of all <a class="link" href="glib-Dynamic-Loading-of-Modules.html#g-module-open" title="g_module_open ()"><code class="function">g_module_open()</code></a> tries to open <em class="parameter"><code>file_name</code></em>
as a module.
If that fails and <em class="parameter"><code>file_name</code></em>
has the ".la"-suffix (and is a libtool
archive) it tries to open the corresponding module. If that fails
and it doesn't have the proper module suffix for the platform
(<a class="link" href="glib-Dynamic-Loading-of-Modules.html#G-MODULE-SUFFIX:CAPS" title="G_MODULE_SUFFIX"><span class="type">G_MODULE_SUFFIX</span></a>), this suffix will be appended and the corresponding
module will be opended. If that fails and <em class="parameter"><code>file_name</code></em>
doesn't have the
".la"-suffix, this suffix is appended and <a class="link" href="glib-Dynamic-Loading-of-Modules.html#g-module-open" title="g_module_open ()"><code class="function">g_module_open()</code></a> tries to open
the corresponding module. If eventually that fails as well, <a class="link" href="glib-Standard-Macros.html#NULL:CAPS" title="NULL"><code class="literal">NULL</code></a> is
returned.</p>
<div class="refsect3">
<a name="g-module-open.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>file_name</p></td>
<td class="parameter_description"><p> the name of the file containing the module, or <a class="link" href="glib-Standard-Macros.html#NULL:CAPS" title="NULL"><code class="literal">NULL</code></a>
to obtain a <a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModule" title="GModule"><span class="type">GModule</span></a> representing the main program itself. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="NULL is OK, both for passing and for returning."><span class="acronym">allow-none</span></acronym>]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>flags</p></td>
<td class="parameter_description"><p>the flags used for opening the module. This can be the
logical OR of any of the <a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModuleFlags" title="enum GModuleFlags"><span class="type">GModuleFlags</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="g-module-open.returns"></a><h4>Returns</h4>
<p> a <a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModule" title="GModule"><span class="type">GModule</span></a> on success, or <a class="link" href="glib-Standard-Macros.html#NULL:CAPS" title="NULL"><code class="literal">NULL</code></a> on failure</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-module-symbol"></a><h3>g_module_symbol ()</h3>
<pre class="programlisting"><a class="link" href="glib-Basic-Types.html#gboolean" title="gboolean"><span class="returnvalue">gboolean</span></a>
g_module_symbol (<em class="parameter"><code><a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModule" title="GModule"><span class="type">GModule</span></a> *module</code></em>,
<em class="parameter"><code>const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="type">gchar</span></a> *symbol_name</code></em>,
<em class="parameter"><code><a class="link" href="glib-Basic-Types.html#gpointer" title="gpointer"><span class="type">gpointer</span></a> *symbol</code></em>);</pre>
<p>Gets a symbol pointer from a module, such as one exported
by <a class="link" href="glib-Dynamic-Loading-of-Modules.html#G-MODULE-EXPORT:CAPS" title="G_MODULE_EXPORT"><span class="type">G_MODULE_EXPORT</span></a>. Note that a valid symbol can be <a class="link" href="glib-Standard-Macros.html#NULL:CAPS" title="NULL"><code class="literal">NULL</code></a>.</p>
<div class="refsect3">
<a name="g-module-symbol.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>module</p></td>
<td class="parameter_description"><p>a <a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModule" title="GModule"><span class="type">GModule</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>symbol_name</p></td>
<td class="parameter_description"><p>the name of the symbol to find</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>symbol</p></td>
<td class="parameter_description"><p> returns the pointer to the symbol value. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="Parameter for returning results. Default is transfer full."><span class="acronym">out</span></acronym>]</span></td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="g-module-symbol.returns"></a><h4>Returns</h4>
<p> <a class="link" href="glib-Standard-Macros.html#TRUE:CAPS" title="TRUE"><code class="literal">TRUE</code></a> on success</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-module-name"></a><h3>g_module_name ()</h3>
<pre class="programlisting">const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="returnvalue">gchar</span></a> *
g_module_name (<em class="parameter"><code><a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModule" title="GModule"><span class="type">GModule</span></a> *module</code></em>);</pre>
<p>Returns the filename that the module was opened with.</p>
<p>If <em class="parameter"><code>module</code></em>
refers to the application itself, "main" is returned.</p>
<div class="refsect3">
<a name="g-module-name.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>module</p></td>
<td class="parameter_description"><p>a <a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModule" title="GModule"><span class="type">GModule</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="g-module-name.returns"></a><h4>Returns</h4>
<p> the filename of the module. </p>
<p><span class="annotation">[<acronym title="Don't free data after the code is done."><span class="acronym">transfer none</span></acronym>]</span></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-module-make-resident"></a><h3>g_module_make_resident ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
g_module_make_resident (<em class="parameter"><code><a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModule" title="GModule"><span class="type">GModule</span></a> *module</code></em>);</pre>
<p>Ensures that a module will never be unloaded.
Any future <a class="link" href="glib-Dynamic-Loading-of-Modules.html#g-module-close" title="g_module_close ()"><code class="function">g_module_close()</code></a> calls on the module will be ignored.</p>
<div class="refsect3">
<a name="g-module-make-resident.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>module</p></td>
<td class="parameter_description"><p>a <a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModule" title="GModule"><span class="type">GModule</span></a> to make permanently resident</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-module-close"></a><h3>g_module_close ()</h3>
<pre class="programlisting"><a class="link" href="glib-Basic-Types.html#gboolean" title="gboolean"><span class="returnvalue">gboolean</span></a>
g_module_close (<em class="parameter"><code><a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModule" title="GModule"><span class="type">GModule</span></a> *module</code></em>);</pre>
<p>Closes a module.</p>
<div class="refsect3">
<a name="g-module-close.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>module</p></td>
<td class="parameter_description"><p>a <a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModule" title="GModule"><span class="type">GModule</span></a> to close</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="g-module-close.returns"></a><h4>Returns</h4>
<p> <a class="link" href="glib-Standard-Macros.html#TRUE:CAPS" title="TRUE"><code class="literal">TRUE</code></a> on success</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-module-error"></a><h3>g_module_error ()</h3>
<pre class="programlisting">const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="returnvalue">gchar</span></a> *
g_module_error (<em class="parameter"><code><span class="type">void</span></code></em>);</pre>
<p>Gets a string describing the last module error.</p>
<div class="refsect3">
<a name="g-module-error.returns"></a><h4>Returns</h4>
<p> a string describing the last module error</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="GModuleCheckInit"></a><h3>GModuleCheckInit ()</h3>
<pre class="programlisting">const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="returnvalue">gchar</span></a> *
<span class="c_punctuation">(</span>*GModuleCheckInit<span class="c_punctuation">)</span> (<em class="parameter"><code><a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModule" title="GModule"><span class="type">GModule</span></a> *module</code></em>);</pre>
<p>Specifies the type of the module initialization function.
If a module contains a function named <code class="function">g_module_check_init()</code> it is called
automatically when the module is loaded. It is passed the <a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModule" title="GModule"><span class="type">GModule</span></a> structure
and should return <a class="link" href="glib-Standard-Macros.html#NULL:CAPS" title="NULL"><code class="literal">NULL</code></a> on success or a string describing the initialization
error.</p>
<div class="refsect3">
<a name="GModuleCheckInit.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>module</p></td>
<td class="parameter_description"><p>the <a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModule" title="GModule"><span class="type">GModule</span></a> corresponding to the module which has just been loaded</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="GModuleCheckInit.returns"></a><h4>Returns</h4>
<p> <a class="link" href="glib-Standard-Macros.html#NULL:CAPS" title="NULL"><code class="literal">NULL</code></a> on success, or a string describing the initialization error</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="GModuleUnload"></a><h3>GModuleUnload ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
<span class="c_punctuation">(</span>*GModuleUnload<span class="c_punctuation">)</span> (<em class="parameter"><code><a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModule" title="GModule"><span class="type">GModule</span></a> *module</code></em>);</pre>
<p>Specifies the type of the module function called when it is unloaded.
If a module contains a function named <code class="function">g_module_unload()</code> it is called
automatically when the module is unloaded.
It is passed the <a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModule" title="GModule"><span class="type">GModule</span></a> structure.</p>
<div class="refsect3">
<a name="GModuleUnload.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>module</p></td>
<td class="parameter_description"><p>the <a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModule" title="GModule"><span class="type">GModule</span></a> about to be unloaded</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
</div>
<div class="refsect1">
<a name="glib-Dynamic-Loading-of-Modules.other_details"></a><h2>Types and Values</h2>
<div class="refsect2">
<a name="GModule"></a><h3>GModule</h3>
<pre class="programlisting">typedef struct _GModule GModule;</pre>
<p>The <a class="link" href="glib-Dynamic-Loading-of-Modules.html#GModule" title="GModule"><span class="type">GModule</span></a> struct is an opaque data structure to represent a
<a class="link" href="glib-Dynamic-Loading-of-Modules.html" title="Dynamic Loading of Modules">dynamically-loaded module</a>.
It should only be accessed via the following functions.</p>
</div>
<hr>
<div class="refsect2">
<a name="GModuleFlags"></a><h3>enum GModuleFlags</h3>
<p>Flags passed to <a class="link" href="glib-Dynamic-Loading-of-Modules.html#g-module-open" title="g_module_open ()"><code class="function">g_module_open()</code></a>.
Note that these flags are not supported on all platforms.</p>
<div class="refsect3">
<a name="GModuleFlags.members"></a><h4>Members</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="300px" class="enum_members_name">
<col class="enum_members_description">
<col width="200px" class="enum_members_annotations">
</colgroup>
<tbody>
<tr>
<td class="enum_member_name"><p><a name="G-MODULE-BIND-LAZY:CAPS"></a>G_MODULE_BIND_LAZY</p></td>
<td class="enum_member_description">
<p>specifies that symbols are only resolved when
needed. The default action is to bind all symbols when the module
is loaded.</p>
</td>
<td class="enum_member_annotations"> </td>
</tr>
<tr>
<td class="enum_member_name"><p><a name="G-MODULE-BIND-LOCAL:CAPS"></a>G_MODULE_BIND_LOCAL</p></td>
<td class="enum_member_description">
<p>specifies that symbols in the module should
not be added to the global name space. The default action on most
platforms is to place symbols in the module in the global name space,
which may cause conflicts with existing symbols.</p>
</td>
<td class="enum_member_annotations"> </td>
</tr>
<tr>
<td class="enum_member_name"><p><a name="G-MODULE-BIND-MASK:CAPS"></a>G_MODULE_BIND_MASK</p></td>
<td class="enum_member_description">
<p>mask for all flags.</p>
</td>
<td class="enum_member_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="G-MODULE-SUFFIX:CAPS"></a><h3>G_MODULE_SUFFIX</h3>
<pre class="programlisting">#define G_MODULE_SUFFIX "so"
</pre>
<p>Expands to the proper shared library suffix for the current platform
without the leading dot. For most Unices and Linux this is "so", and
for Windows this is "dll".</p>
</div>
<hr>
<div class="refsect2">
<a name="G-MODULE-EXPORT:CAPS"></a><h3>G_MODULE_EXPORT</h3>
<pre class="programlisting"># define G_MODULE_EXPORT __declspec(dllexport)
</pre>
<p>Used to declare functions exported by modules. This is a no-op on Linux
and Unices, but when compiling for Windows, it marks a symbol to be
exported from the library or executable being built.</p>
</div>
<hr>
<div class="refsect2">
<a name="G-MODULE-IMPORT:CAPS"></a><h3>G_MODULE_IMPORT</h3>
<pre class="programlisting">#define G_MODULE_IMPORT extern
</pre>
<p>Used to declare functions imported from modules.</p>
</div>
</div>
</div>
<div class="footer">
<hr>Generated by GTK-Doc V1.25.1</div>
</body>
</html>