libudev/docs/html/libudev-udev.html

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  20 <th width="100%" align="center">libudev Reference Manual</th>
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  24 <a href="#libudev-udev.synopsis" class="shortcut">Top</a>
  25                    |
  26                   <a href="#libudev-udev.description" class="shortcut">Description</a>
  27 </td></tr>
  28 </table>
  29 <div class="refentry">
  30 <a name="libudev-udev"></a><div class="titlepage"></div>
  31 <div class="refnamediv"><table width="100%"><tr>
  32 <td valign="top">
  33 <h2><span class="refentrytitle"><a name="libudev-udev.top_of_page"></a>udev</span></h2>
  34 <p>udev — libudev context</p>
  35 </td>
  36 <td valign="top" align="right"></td>
  37 </tr></table></div>
  38 <div class="refsynopsisdiv">
  39 <a name="libudev-udev.synopsis"></a><h2>Synopsis</h2>
  40 <pre class="synopsis">struct              <a class="link" href="libudev-udev.html#udev" title="struct udev">udev</a>;
  41 struct <a class="link" href="libudev-udev.html#udev" title="struct udev"><span class="returnvalue">udev</span></a> *       <a class="link" href="libudev-udev.html#udev-ref" title="udev_ref ()">udev_ref</a>                            (<em class="parameter"><code><span class="type">struct udev</span> *udev</code></em>);
  42 <span class="returnvalue">void</span>                <a class="link" href="libudev-udev.html#udev-unref" title="udev_unref ()">udev_unref</a>                          (<em class="parameter"><code><span class="type">struct udev</span> *udev</code></em>);
  43 struct <a class="link" href="libudev-udev.html#udev" title="struct udev"><span class="returnvalue">udev</span></a> *       <a class="link" href="libudev-udev.html#udev-new" title="udev_new ()">udev_new</a>                            (<em class="parameter"><code><span class="type">void</span></code></em>);
  44 <span class="returnvalue">void</span>                <a class="link" href="libudev-udev.html#udev-set-log-fn" title="udev_set_log_fn ()">udev_set_log_fn</a>                     (<em class="parameter"><code><span class="type">struct udev</span> *udev</code></em>,
  45                                                          <em class="parameter"><code><span class="type">void</span> (*log_fn) (struct udev *udev, int priority, const char *file, int line, const char *fn, const char *format, va_list args)</code></em>);
  46 <span class="returnvalue">int</span>                 <a class="link" href="libudev-udev.html#udev-get-log-priority" title="udev_get_log_priority ()">udev_get_log_priority</a>               (<em class="parameter"><code><span class="type">struct udev</span> *udev</code></em>);
  47 <span class="returnvalue">void</span>                <a class="link" href="libudev-udev.html#udev-set-log-priority" title="udev_set_log_priority ()">udev_set_log_priority</a>               (<em class="parameter"><code><span class="type">struct udev</span> *udev</code></em>,
  48                                                          <em class="parameter"><code><span class="type">int</span> priority</code></em>);
  49 const <span class="returnvalue">char</span> *        <a class="link" href="libudev-udev.html#udev-get-sys-path" title="udev_get_sys_path ()">udev_get_sys_path</a>                   (<em class="parameter"><code><span class="type">struct udev</span> *udev</code></em>);
  50 const <span class="returnvalue">char</span> *        <a class="link" href="libudev-udev.html#udev-get-dev-path" title="udev_get_dev_path ()">udev_get_dev_path</a>                   (<em class="parameter"><code><span class="type">struct udev</span> *udev</code></em>);
  51 const <span class="returnvalue">char</span> *        <a class="link" href="libudev-udev.html#udev-get-run-path" title="udev_get_run_path ()">udev_get_run_path</a>                   (<em class="parameter"><code><span class="type">struct udev</span> *udev</code></em>);
  52 <span class="returnvalue">void</span> *              <a class="link" href="libudev-udev.html#udev-get-userdata" title="udev_get_userdata ()">udev_get_userdata</a>                   (<em class="parameter"><code><span class="type">struct udev</span> *udev</code></em>);
  53 <span class="returnvalue">void</span>                <a class="link" href="libudev-udev.html#udev-set-userdata" title="udev_set_userdata ()">udev_set_userdata</a>                   (<em class="parameter"><code><span class="type">struct udev</span> *udev</code></em>,
  54                                                          <em class="parameter"><code><span class="type">void</span> *userdata</code></em>);
  55 </pre>
  56 </div>
  57 <div class="refsect1">
  58 <a name="libudev-udev.description"></a><h2>Description</h2>
  59 <p>
  60 The context contains the default values read from the udev config file,
  61 and is passed to all library operations.
  62 </p>
  63 </div>
  64 <div class="refsect1">
  65 <a name="libudev-udev.details"></a><h2>Details</h2>
  66 <div class="refsect2">
  67 <a name="udev"></a><h3>struct udev</h3>
  68 <pre class="programlisting">struct udev;</pre>
  69 <p>
  70 Opaque object representing the library context.
  71 </p>
  72 </div>
  73 <hr>
  74 <div class="refsect2">
  75 <a name="udev-ref"></a><h3>udev_ref ()</h3>
  76 <pre class="programlisting">struct <a class="link" href="libudev-udev.html#udev" title="struct udev"><span class="returnvalue">udev</span></a> *       udev_ref                            (<em class="parameter"><code><span class="type">struct udev</span> *udev</code></em>);</pre>
  77 <p>
  78 Take a reference of the udev library context.
  79 </p>
  80 <div class="variablelist"><table border="0">
  81 <col align="left" valign="top">
  82 <tbody>
  83 <tr>
  84 <td><p><span class="term"><em class="parameter"><code>udev</code></em> :</span></p></td>
  85 <td>udev library context</td>
  86 </tr>
  87 <tr>
  88 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
  89 <td>the passed udev library context</td>
  90 </tr>
  91 </tbody>
  92 </table></div>
  93 </div>
  94 <hr>
  95 <div class="refsect2">
  96 <a name="udev-unref"></a><h3>udev_unref ()</h3>
  97 <pre class="programlisting"><span class="returnvalue">void</span>                udev_unref                          (<em class="parameter"><code><span class="type">struct udev</span> *udev</code></em>);</pre>
  98 <p>
  99 Drop a reference of the udev library context. If the refcount
 100 reaches zero, the resources of the context will be released.
 101 </p>
 102 <div class="variablelist"><table border="0">
 103 <col align="left" valign="top">
 104 <tbody><tr>
 105 <td><p><span class="term"><em class="parameter"><code>udev</code></em> :</span></p></td>
 106 <td>udev library context</td>
 107 </tr></tbody>
 108 </table></div>
 109 </div>
 110 <hr>
 111 <div class="refsect2">
 112 <a name="udev-new"></a><h3>udev_new ()</h3>
 113 <pre class="programlisting">struct <a class="link" href="libudev-udev.html#udev" title="struct udev"><span class="returnvalue">udev</span></a> *       udev_new                            (<em class="parameter"><code><span class="type">void</span></code></em>);</pre>
 114 <p>
 115 Create udev library context. This reads the udev configuration
 116 file, and fills in the default values.
 117 </p>
 118 <p>
 119 The initial refcount is 1, and needs to be decremented to
 120 release the resources of the udev library context.
 121 </p>
 122 <div class="variablelist"><table border="0">
 123 <col align="left" valign="top">
 124 <tbody><tr>
 125 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 126 <td>a new udev library context</td>
 127 </tr></tbody>
 128 </table></div>
 129 </div>
 130 <hr>
 131 <div class="refsect2">
 132 <a name="udev-set-log-fn"></a><h3>udev_set_log_fn ()</h3>
 133 <pre class="programlisting"><span class="returnvalue">void</span>                udev_set_log_fn                     (<em class="parameter"><code><span class="type">struct udev</span> *udev</code></em>,
 134                                                          <em class="parameter"><code><span class="type">void</span> (*log_fn) (struct udev *udev, int priority, const char *file, int line, const char *fn, const char *format, va_list args)</code></em>);</pre>
 135 <p>
 136 The built-in logging writes to stderr. It can be
 137 overridden by a custom function, to plug log messages
 138 into the users' logging functionality.
 139 </p>
 140 <div class="variablelist"><table border="0">
 141 <col align="left" valign="top">
 142 <tbody>
 143 <tr>
 144 <td><p><span class="term"><em class="parameter"><code>udev</code></em> :</span></p></td>
 145 <td>udev library context</td>
 146 </tr>
 147 <tr>
 148 <td><p><span class="term"><em class="parameter"><code>log_fn</code></em> :</span></p></td>
 149 <td>function to be called for logging messages</td>
 150 </tr>
 151 </tbody>
 152 </table></div>
 153 </div>
 154 <hr>
 155 <div class="refsect2">
 156 <a name="udev-get-log-priority"></a><h3>udev_get_log_priority ()</h3>
 157 <pre class="programlisting"><span class="returnvalue">int</span>                 udev_get_log_priority               (<em class="parameter"><code><span class="type">struct udev</span> *udev</code></em>);</pre>
 158 <p>
 159 The initial logging priority is read from the udev config file
 160 at startup.
 161 </p>
 162 <div class="variablelist"><table border="0">
 163 <col align="left" valign="top">
 164 <tbody>
 165 <tr>
 166 <td><p><span class="term"><em class="parameter"><code>udev</code></em> :</span></p></td>
 167 <td>udev library context</td>
 168 </tr>
 169 <tr>
 170 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 171 <td>the current logging priority</td>
 172 </tr>
 173 </tbody>
 174 </table></div>
 175 </div>
 176 <hr>
 177 <div class="refsect2">
 178 <a name="udev-set-log-priority"></a><h3>udev_set_log_priority ()</h3>
 179 <pre class="programlisting"><span class="returnvalue">void</span>                udev_set_log_priority               (<em class="parameter"><code><span class="type">struct udev</span> *udev</code></em>,
 180                                                          <em class="parameter"><code><span class="type">int</span> priority</code></em>);</pre>
 181 <p>
 182 Set the current logging priority. The value controls which messages
 183 are logged.
 184 </p>
 185 <div class="variablelist"><table border="0">
 186 <col align="left" valign="top">
 187 <tbody>
 188 <tr>
 189 <td><p><span class="term"><em class="parameter"><code>udev</code></em> :</span></p></td>
 190 <td>udev library context</td>
 191 </tr>
 192 <tr>
 193 <td><p><span class="term"><em class="parameter"><code>priority</code></em> :</span></p></td>
 194 <td>the new logging priority</td>
 195 </tr>
 196 </tbody>
 197 </table></div>
 198 </div>
 199 <hr>
 200 <div class="refsect2">
 201 <a name="udev-get-sys-path"></a><h3>udev_get_sys_path ()</h3>
 202 <pre class="programlisting">const <span class="returnvalue">char</span> *        udev_get_sys_path                   (<em class="parameter"><code><span class="type">struct udev</span> *udev</code></em>);</pre>
 203 <p>
 204 Retrieve the sysfs mount point. The default is "/sys". For
 205 testing purposes, it can be overridden with the environment
 206 variable SYSFS_PATH.
 207 </p>
 208 <div class="variablelist"><table border="0">
 209 <col align="left" valign="top">
 210 <tbody>
 211 <tr>
 212 <td><p><span class="term"><em class="parameter"><code>udev</code></em> :</span></p></td>
 213 <td>udev library context</td>
 214 </tr>
 215 <tr>
 216 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 217 <td>the sys mount point</td>
 218 </tr>
 219 </tbody>
 220 </table></div>
 221 </div>
 222 <hr>
 223 <div class="refsect2">
 224 <a name="udev-get-dev-path"></a><h3>udev_get_dev_path ()</h3>
 225 <pre class="programlisting">const <span class="returnvalue">char</span> *        udev_get_dev_path                   (<em class="parameter"><code><span class="type">struct udev</span> *udev</code></em>);</pre>
 226 <p>
 227 Retrieve the device directory path. The default value is "/dev",
 228 the actual value may be overridden in the udev configuration
 229 file.
 230 </p>
 231 <div class="variablelist"><table border="0">
 232 <col align="left" valign="top">
 233 <tbody>
 234 <tr>
 235 <td><p><span class="term"><em class="parameter"><code>udev</code></em> :</span></p></td>
 236 <td>udev library context</td>
 237 </tr>
 238 <tr>
 239 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 240 <td>the device directory path</td>
 241 </tr>
 242 </tbody>
 243 </table></div>
 244 </div>
 245 <hr>
 246 <div class="refsect2">
 247 <a name="udev-get-run-path"></a><h3>udev_get_run_path ()</h3>
 248 <pre class="programlisting">const <span class="returnvalue">char</span> *        udev_get_run_path                   (<em class="parameter"><code><span class="type">struct udev</span> *udev</code></em>);</pre>
 249 <p>
 250 Retrieve the udev runtime directory path. The default is "/run/udev".
 251 </p>
 252 <div class="variablelist"><table border="0">
 253 <col align="left" valign="top">
 254 <tbody>
 255 <tr>
 256 <td><p><span class="term"><em class="parameter"><code>udev</code></em> :</span></p></td>
 257 <td>udev library context</td>
 258 </tr>
 259 <tr>
 260 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 261 <td>the runtime directory path</td>
 262 </tr>
 263 </tbody>
 264 </table></div>
 265 </div>
 266 <hr>
 267 <div class="refsect2">
 268 <a name="udev-get-userdata"></a><h3>udev_get_userdata ()</h3>
 269 <pre class="programlisting"><span class="returnvalue">void</span> *              udev_get_userdata                   (<em class="parameter"><code><span class="type">struct udev</span> *udev</code></em>);</pre>
 270 <p>
 271 Retrieve stored data pointer from library context. This might be useful
 272 to access from callbacks like a custom logging function.
 273 </p>
 274 <div class="variablelist"><table border="0">
 275 <col align="left" valign="top">
 276 <tbody>
 277 <tr>
 278 <td><p><span class="term"><em class="parameter"><code>udev</code></em> :</span></p></td>
 279 <td>udev library context</td>
 280 </tr>
 281 <tr>
 282 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 283 <td>stored userdata</td>
 284 </tr>
 285 </tbody>
 286 </table></div>
 287 </div>
 288 <hr>
 289 <div class="refsect2">
 290 <a name="udev-set-userdata"></a><h3>udev_set_userdata ()</h3>
 291 <pre class="programlisting"><span class="returnvalue">void</span>                udev_set_userdata                   (<em class="parameter"><code><span class="type">struct udev</span> *udev</code></em>,
 292                                                          <em class="parameter"><code><span class="type">void</span> *userdata</code></em>);</pre>
 293 <p>
 294 Store custom <em class="parameter"><code>userdata</code></em> in the library context.
 295 </p>
 296 <div class="variablelist"><table border="0">
 297 <col align="left" valign="top">
 298 <tbody>
 299 <tr>
 300 <td><p><span class="term"><em class="parameter"><code>udev</code></em> :</span></p></td>
 301 <td>udev library context</td>
 302 </tr>
 303 <tr>
 304 <td><p><span class="term"><em class="parameter"><code>userdata</code></em> :</span></p></td>
 305 <td>data pointer</td>
 306 </tr>
 307 </tbody>
 308 </table></div>
 309 </div>
 310 </div>
 311 </div>
 312 <div class="footer">
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