<p>Error domain for option parsing. Errors in this domain willbe from the <a href="glib-Commandline-option-parser.html#GOptionError"><span class="type">GOptionError</span></a> enumeration. See <a href="glib-Error-Reporting.html#GError"><span class="type">GError</span></a> for information on error domains.</p></div><hr><div class="refsect2" lang="en"><a name="id3063585"></a><h3><a name="GOptionArgFunc"></a>GOptionArgFunc ()</h3><a class="indexterm" name="id3063596"></a><pre class="programlisting"><a href="glib-Basic-Types.html#gboolean">gboolean</a>    (*GOptionArgFunc)               (const <a href="glib-Basic-Types.html#gchar">gchar</a> *option_name,                                             const <a href="glib-Basic-Types.html#gchar">gchar</a> *value,                                             <a href="glib-Basic-Types.html#gpointer">gpointer</a> data,                                             <a href="glib-Error-Reporting.html#GError">GError</a> **error);</pre><p>The type of function to be passed as callback for <code class="literal">G_OPTION_ARG_CALLBACK</code>options.</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><em class="parameter"><code>option_name</code></em>&#160;:</span></td><td>The name of the option being parsed. This will be either a   single dash followed by a single letter (for a short name) or two dashes  followed by a long option name.</td></tr><tr><td><span class="term"><em class="parameter"><code>value</code></em>&#160;:</span></td><td>The value to be parsed.</td></tr><tr><td><span class="term"><em class="parameter"><code>data</code></em>&#160;:</span></td><td>User data added to the <a href="glib-Commandline-option-parser.html#GOptionGroup"><span class="type">GOptionGroup</span></a> containing the option when it  was created with <a href="glib-Commandline-option-parser.html#g-option-group-new"><code class="function">g_option_group_new()</code></a></td></tr><tr><td><span class="term"><em class="parameter"><code>error</code></em>&#160;:</span></td><td>A return location for errors. The error code <code class="literal">G_OPTION_ERROR_FAILED</code>  is intended to be used for errors in <a href="glib-Commandline-option-parser.html#GOptionArgFunc"><span class="type">GOptionArgFunc</span></a> callbacks.</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></td><td><code class="literal">TRUE</code> if the option was successfully parsed, <code class="literal">FALSE</code> if an error   occurred</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3063774"></a><h3><a name="GOptionContext"></a>GOptionContext</h3><a class="indexterm" name="id3063785"></a><pre class="programlisting">typedef struct _GOptionContext GOptionContext;</pre><p>A <span class="structname">GOptionContext</span> struct defines which optionsare accepted by the commandline option parser. The struct has only private fields and should not be directly accessed.</p></div><hr><div class="refsect2" lang="en"><a name="id3063807"></a><h3><a name="g-option-context-new"></a>g_option_context_new ()</h3><a class="indexterm" name="id3063818"></a><pre class="programlisting"><a href="glib-Commandline-option-parser.html#GOptionContext">GOptionContext</a>* g_option_context_new        (const <a href="glib-Basic-Types.html#gchar">gchar</a> *parameter_string);</pre><p>Creates a new option context.</p><p></p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><em class="parameter"><code>parameter_string</code></em>&#160;:</span></td><td> a string which is displayed in   the first line of <code class="option">--help</code> output, after    <code class="literal"><em class="replaceable"><code>programname</code></em> [OPTION...]</code></td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></td><td> a newly created <a href="glib-Commandline-option-parser.html#GOptionContext"><span class="type">GOptionContext</span></a>, which must be   freed with <a href="glib-Commandline-option-parser.html#g-option-context-free"><code class="function">g_option_context_free()</code></a> after use.</td></tr></tbody></table></div><p>Since  2.6</p></div><hr><div class="refsect2" lang="en"><a name="id3063917"></a><h3><a name="g-option-context-free"></a>g_option_context_free ()</h3><a class="indexterm" name="id3063928"></a><pre class="programlisting">void        g_option_context_free           (<a href="glib-Commandline-option-parser.html#GOptionContext">GOptionContext</a> *context);</pre><p>Frees context and all the groups which have been added to it.</p><p></p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><em class="parameter"><code>context</code></em>&#160;:</span></td><td> a <a href="glib-Commandline-option-parser.html#GOptionContext"><span class="type">GOptionContext</span></a> </td></tr></tbody></table></div><p>Since  2.6</p></div><hr><div class="refsect2" lang="en"><a name="id3063991"></a><h3><a name="g-option-context-parse"></a>g_option_context_parse ()</h3><a class="indexterm" name="id3064002"></a><pre class="programlisting"><a href="glib-Basic-Types.html#gboolean">gboolean</a>    g_option_context_parse          (<a href="glib-Commandline-option-parser.html#GOptionContext">GOptionContext</a> *context,                                             <a href="glib-Basic-Types.html#gint">gint</a> *argc,                                             <a href="glib-Basic-Types.html#gchar">gchar</a> ***argv,                                             <a href="glib-Error-Reporting.html#GError">GError</a> **error);</pre><p>Parses the command line arguments, recognizing optionswhich have been added to <em class="parameter"><code>context</code></em>. A side-effect of calling this function is that <a href="glib-Miscellaneous-Utility-Functions.html#g-set-prgname"><code class="function">g_set_prgname()</code></a> will becalled.</p><p>If the parsing is successful, any parsed arguments areremoved from the array and <em class="parameter"><code>argc</code></em> and <em class="parameter"><code>argv</code></em> are updated accordingly. A '--' option is stripped from <em class="parameter"><code>argv</code></em>unless there are unparsed options before and after it, or some of the options after it start with '-'. In case of an error, <em class="parameter"><code>argc</code></em> and <em class="parameter"><code>argv</code></em> are left unmodified. </p><p>If automatic <code class="option">--help</code> support is enabled(see <a href="glib-Commandline-option-parser.html#g-option-context-set-help-enabled"><code class="function">g_option_context_set_help_enabled()</code></a>), and the <em class="parameter"><code>argv</code></em> array contains one of the recognized help options,this function will produce help output to stdout andcall <code class="literal">exit (0)</code>.</p><p></p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><em class="parameter"><code>context</code></em>&#160;:</span></td><td> a <a href="glib-Commandline-option-parser.html#GOptionContext"><span class="type">GOptionContext</span></a></td></tr><tr><td><span class="term"><em class="parameter"><code>argc</code></em>&#160;:</span></td><td> a pointer to the number of command line arguments.</td></tr><tr><td><span class="term"><em class="parameter"><code>argv</code></em>&#160;:</span></td><td> a pointer to the array of command line arguments.</td></tr><tr><td><span class="term"><em class="parameter"><code>error</code></em>&#160;:</span></td><td> a return location for errors </td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></td><td> <code class="literal">TRUE</code> if the parsing was successful,               <code class="literal">FALSE</code> if an error occurred</td></tr></tbody></table></div><p>Since  2.6</p></div><hr><div class="refsect2" lang="en"><a name="id3064243"></a><h3><a name="g-option-context-set-help-enabled"></a>g_option_context_set_help_enabled ()</h3><a class="indexterm" name="id3064255"></a><pre class="programlisting">void        g_option_context_set_help_enabled                                            (<a href="glib-Commandline-option-parser.html#GOptionContext">GOptionContext</a> *context,                                             <a href="glib-Basic-Types.html#gboolean">gboolean</a> help_enabled);</pre><p>Enables or disables automatic generation of <code class="option">--help</code> output. By default, <a href="glib-Commandline-option-parser.html#g-option-context-parse"><code class="function">g_option_context_parse()</code></a> recognizes<code class="option">--help</code>, <code class="option">-?</code>, <code class="option">--help-all</code>and <code class="option">--help-</code><em class="replaceable"><code>groupname</code></em> and createssuitable output to stdout.</p><p></p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><em class="parameter"><code>context</code></em>&#160;:</span></td><td> a <a href="glib-Commandline-option-parser.html#GOptionContext"><span class="type">GOptionContext</span></a></td></tr><tr><td><span class="term"><em class="parameter"><code>help_enabled</code></em>&#160;:</span></td><td> <code class="literal">TRUE</code> to enable <code class="option">--help</code>, <code class="literal">FALSE</code> to disable it</td></tr></tbody></table></div><p>Since  2.6</p></div><hr><div class="refsect2" lang="en"><a name="id3064388"></a><h3><a name="g-option-context-get-help-enabled"></a>g_option_context_get_help_enabled ()</h3><a class="indexterm" name="id3064400"></a><pre class="programlisting"><a href="glib-Basic-Types.html#gboolean">gboolean</a>    g_option_context_get_help_enabled                                            (<a href="glib-Commandline-option-parser.html#GOptionContext">GOptionContext</a> *context);</pre><p>Returns whether automatic <code class="option">--help</code> generationis turned on for <em class="parameter"><code>context</code></em>. See <a href="glib-Commandline-option-parser.html#g-option-context-set-help-enabled"><code class="function">g_option_context_set_help_enabled()</code></a>.</p><p></p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><em class="parameter"><code>context</code></em>&#160;:</span></td><td> a <a href="glib-Commandline-option-parser.html#GOptionContext"><span class="type">GOptionContext</span></a></td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></td><td> <code class="literal">TRUE</code> if automatic help generation is turned on.</td></tr></tbody></table></div><p>Since  2.6</p></div><hr><div class="refsect2" lang="en"><a name="id3064501"></a><h3><a name="g-option-context-set-ignore-unknown-options"></a>g_option_context_set_ignore_unknown_options ()</h3><a class="indexterm" name="id3064514"></a><pre class="programlisting">void        g_option_context_set_ignore_unknown_options                                            (<a href="glib-Commandline-option-parser.html#GOptionContext">GOptionContext</a> *context,                                             <a href="glib-Basic-Types.html#gboolean">gboolean</a> ignore_unknown);</pre><p>Sets whether to ignore unknown options or not. If an argument is ignored, it is left in the <em class="parameter"><code>argv</code></em> array after parsing. By default,