glib-miscellaneous-utility-functions.html

glid编写实例

<p>
Find the position of the first bit set in <em class="parameter"><code>mask</code></em>, searching from (but not
including) <em class="parameter"><code>nth_bit</code></em> upwards. Bits are numbered from 0 (least significant)
to sizeof(<a href="glib-Basic-Types.html#gulong"><span class="type">gulong</span></a>) * 8 - 1 (31 or 63, usually). To start searching from the
0th bit, set <em class="parameter"><code>nth_bit</code></em> to -1.
</p>
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<td>
<span class="term"><em class="parameter"><code>mask</code></em>&#160;:</span></td>
<td>a <a href="glib-Basic-Types.html#gulong"><span class="type">gulong</span></a> containing flags.
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>nth_bit</code></em>&#160;:</span></td>
<td>the index of the bit to start the search from.
</td>
</tr>
<tr>
<td>
<span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></td>
<td>the index of the first bit set which is higher than <em class="parameter"><code>nth_bit</code></em>.


</td>
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<hr>
<div class="refsect2" lang="en">
<a name="id3023254"></a><h3>
<a name="g-bit-nth-msf"></a>g_bit_nth_msf ()</h3>
<a class="indexterm" name="id3023265"></a><pre class="programlisting"><a href="glib-Basic-Types.html#gint">gint</a>        g_bit_nth_msf                   (<a href="glib-Basic-Types.html#gulong">gulong</a> mask,
                                             <a href="glib-Basic-Types.html#gint">gint</a> nth_bit);</pre>
<p>
Find the position of the first bit set in <em class="parameter"><code>mask</code></em>, searching from (but not
including) <em class="parameter"><code>nth_bit</code></em> downwards. Bits are numbered from 0 (least significant)
to sizeof(<a href="glib-Basic-Types.html#gulong"><span class="type">gulong</span></a>) * 8 - 1 (31 or 63, usually). To start searching from the
last bit, set <em class="parameter"><code>nth_bit</code></em> to -1 or GLIB_SIZEOF_LONG * 8.
</p>
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<td>
<span class="term"><em class="parameter"><code>mask</code></em>&#160;:</span></td>
<td>a <a href="glib-Basic-Types.html#gulong"><span class="type">gulong</span></a> containing flags.
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>nth_bit</code></em>&#160;:</span></td>
<td>the index of the bit to start the search from.
</td>
</tr>
<tr>
<td>
<span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></td>
<td>the index of the first bit set which is lower than <em class="parameter"><code>nth_bit</code></em>.


</td>
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<hr>
<div class="refsect2" lang="en">
<a name="id3023388"></a><h3>
<a name="g-bit-storage"></a>g_bit_storage ()</h3>
<a class="indexterm" name="id3023398"></a><pre class="programlisting"><a href="glib-Basic-Types.html#guint">guint</a>       g_bit_storage                   (<a href="glib-Basic-Types.html#gulong">gulong</a> number);</pre>
<p>
Gets the number of bits used to hold <em class="parameter"><code>number</code></em>,
e.g. if <em class="parameter"><code>number</code></em> is 4, 3 bits are needed.
</p>
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<span class="term"><em class="parameter"><code>number</code></em>&#160;:</span></td>
<td>a guint.
</td>
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<td>
<span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></td>
<td>the number of bits used to hold <em class="parameter"><code>number</code></em>.


</td>
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<hr>
<div class="refsect2" lang="en">
<a name="id3023474"></a><h3>
<a name="g-spaced-primes-closest"></a>g_spaced_primes_closest ()</h3>
<a class="indexterm" name="id3023485"></a><pre class="programlisting"><a href="glib-Basic-Types.html#guint">guint</a>       g_spaced_primes_closest         (<a href="glib-Basic-Types.html#guint">guint</a> num);</pre>
<p>
Gets the smallest prime number from a built-in array of primes which
is larger than <em class="parameter"><code>num</code></em>. This is used within GLib to calculate the optimum
size of a <a href="glib-Hash-Tables.html#GHashTable"><span class="type">GHashTable</span></a>.
</p>
<p>
The built-in array of primes ranges from 11 to 13845163 such that
each prime is approximately 1.5-2 times the previous prime.
</p>
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<span class="term"><em class="parameter"><code>num</code></em>&#160;:</span></td>
<td>a <a href="glib-Basic-Types.html#guint"><span class="type">guint</span></a>.
</td>
</tr>
<tr>
<td>
<span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></td>
<td>the smallest prime number from a built-in array of primes which is
larger than <em class="parameter"><code>num</code></em>.


</td>
</tr>
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</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id3023579"></a><h3>
<a name="g-atexit"></a>g_atexit ()</h3>
<a class="indexterm" name="id3023589"></a><pre class="programlisting">void        g_atexit                        (<a href="glib-Miscellaneous-Utility-Functions.html#GVoidFunc">GVoidFunc</a> func);</pre>
<p>
Specifies a function to be called at normal program termination.
</p>
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<td>
<span class="term"><em class="parameter"><code>func</code></em>&#160;:</span></td>
<td>the function to call on normal program termination.


</td>
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<hr>
<div class="refsect2" lang="en">
<a name="id3023637"></a><h3>
<a name="g-parse-debug-string"></a>g_parse_debug_string ()</h3>
<a class="indexterm" name="id3023648"></a><pre class="programlisting"><a href="glib-Basic-Types.html#guint">guint</a>       g_parse_debug_string            (const <a href="glib-Basic-Types.html#gchar">gchar</a> *string,
                                             const <a href="glib-Miscellaneous-Utility-Functions.html#GDebugKey">GDebugKey</a> *keys,
                                             <a href="glib-Basic-Types.html#guint">guint</a> nkeys);</pre>
<p>
Parses a string containing debugging options separated by ':' into a guint
containing bit flags.
This is used within GDK and GTK+ to parse the debug options passed on the
command line or through environment variables.
</p>
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<span class="term"><em class="parameter"><code>string</code></em>&#160;:</span></td>
<td>a list of debug options separated by ':' or "all" to set all flags.
</td>
</tr>
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<td>
<span class="term"><em class="parameter"><code>keys</code></em>&#160;:</span></td>
<td>pointer to an array of <a href="glib-Miscellaneous-Utility-Functions.html#GDebugKey"><span class="type">GDebugKey</span></a> which associate strings with
bit flags.
</td>
</tr>
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<td>
<span class="term"><em class="parameter"><code>nkeys</code></em>&#160;:</span></td>
<td>the number of <a href="glib-Miscellaneous-Utility-Functions.html#GDebugKey"><span class="type">GDebugKey</span></a> in the array.
</td>
</tr>
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<td>
<span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></td>
<td>the combined set of bit flags.


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</div>
<hr>
<div class="refsect2" lang="en">
<a name="id3023770"></a><h3>
<a name="GDebugKey"></a>GDebugKey</h3>
<a class="indexterm" name="id3023780"></a><pre class="programlisting">typedef struct {
  gchar *key;
  guint	 value;
} GDebugKey;
</pre>
<p>
Associates a string with a bit flag.
Used in <a href="glib-Miscellaneous-Utility-Functions.html#g-parse-debug-string"><code class="function">g_parse_debug_string()</code></a>.
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id3023808"></a><h3>
<a name="GVoidFunc"></a>GVoidFunc ()</h3>
<a class="indexterm" name="id3023818"></a><pre class="programlisting">void        (*GVoidFunc)                    (void);</pre>
<p>
Declares a type of function which takes no arguments and has no return value.
It is used to specify the type function passed to <a href="glib-Miscellaneous-Utility-Functions.html#g-atexit"><code class="function">g_atexit()</code></a>.
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id3023852"></a><h3>
<a name="GFreeFunc"></a>GFreeFunc ()</h3>
<a class="indexterm" name="id3023862"></a><pre class="programlisting">void        (*GFreeFunc)                    (<a href="glib-Basic-Types.html#gpointer">gpointer</a> data);</pre>
<p>
Declares a type of function which takes an arbitrary data pointer argument
and has no return value. It is not currently used in GLib or GTK+.
</p>
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<span class="term"><em class="parameter"><code>data</code></em>&#160;:</span></td>
<td>a data pointer.


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<hr>
<div class="refsect2" lang="en">
<a name="id3023911"></a><h3>
<a name="g-qsort-with-data"></a>g_qsort_with_data ()</h3>
<a class="indexterm" name="id3023922"></a><pre class="programlisting">void        g_qsort_with_data               (<a href="glib-Basic-Types.html#gconstpointer">gconstpointer</a> pbase,
                                             <a href="glib-Basic-Types.html#gint">gint</a> total_elems,
                                             <a href="glib-Basic-Types.html#gsize">gsize</a> size,
                                             <a href="glib-Doubly-Linked-Lists.html#GCompareDataFunc">GCompareDataFunc</a> compare_func,
                                             <a href="glib-Basic-Types.html#gpointer">gpointer</a> user_data);</pre>
<p>
This is just like the standard C <code class="function">qsort()</code> function, but
the comparison routine accepts a user data argument.</p>
<p>

</p>
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<span class="term"><em class="parameter"><code>pbase</code></em>&#160;:</span></td>
<td> start of array to sort
</td>
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<td>
<span class="term"><em class="parameter"><code>total_elems</code></em>&#160;:</span></td>
<td> elements in the array
</td>
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<td>
<span class="term"><em class="parameter"><code>size</code></em>&#160;:</span></td>
<td> size of each element
</td>
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<td>
<span class="term"><em class="parameter"><code>compare_func</code></em>&#160;:</span></td>
<td> function to compare elements
</td>
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<td>
<span class="term"><em class="parameter"><code>user_data</code></em>&#160;:</span></td>
<td> data to pass to <em class="parameter"><code>compare_func</code></em>
</td>
</tr>
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</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id3024077"></a><h3>
<a name="g-nullify-pointer"></a>g_nullify_pointer ()</h3>
<a class="indexterm" name="id3024088"></a><pre class="programlisting">void        g_nullify_pointer               (<a href="glib-Basic-Types.html#gpointer">gpointer</a> *nullify_location);</pre>
<p>
Set the pointer at the specified location to <code class="literal">NULL</code>.</p>
<p>

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<span class="term"><em class="parameter"><code>nullify_location</code></em>&#160;:</span></td>
<td> the memory address of the pointer.
</td>
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</div>
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</div>
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