glib-io-channels.html

最新gtk中文资料集

manner using <a class="link" href="glib-IO-Channels.html#g-io-channel-new-file"><code class="function">g_io_channel_new_file()</code></a>.
</p>
<p>
Once a <a class="link" href="glib-IO-Channels.html#GIOChannel"><span class="type">GIOChannel</span></a> has been created, it can be used in a generic manner
with the functions <a class="link" href="glib-IO-Channels.html#g-io-channel-read-chars"><code class="function">g_io_channel_read_chars()</code></a>, <a class="link" href="glib-IO-Channels.html#g-io-channel-write-chars"><code class="function">g_io_channel_write_chars()</code></a>,
<a class="link" href="glib-IO-Channels.html#g-io-channel-seek-position"><code class="function">g_io_channel_seek_position()</code></a>, and <a class="link" href="glib-IO-Channels.html#g-io-channel-shutdown"><code class="function">g_io_channel_shutdown()</code></a>.
</p>
<p>
To add a <a class="link" href="glib-IO-Channels.html#GIOChannel"><span class="type">GIOChannel</span></a> to the 
<a class="link" href="glib-The-Main-Event-Loop.html" title="The Main Event Loop">main event loop</a>
use <a class="link" href="glib-IO-Channels.html#g-io-add-watch"><code class="function">g_io_add_watch()</code></a> or <a class="link" href="glib-IO-Channels.html#g-io-add-watch-full"><code class="function">g_io_add_watch_full()</code></a>. Here you specify which events
you are interested in on the <a class="link" href="glib-IO-Channels.html#GIOChannel"><span class="type">GIOChannel</span></a>, and provide a function to be
called whenever these events occur.
</p>
<p>
<a class="link" href="glib-IO-Channels.html#GIOChannel"><span class="type">GIOChannel</span></a> instances are created with an initial reference count of 1.
<a class="link" href="glib-IO-Channels.html#g-io-channel-ref"><code class="function">g_io_channel_ref()</code></a> and <a class="link" href="glib-IO-Channels.html#g-io-channel-unref"><code class="function">g_io_channel_unref()</code></a> can be used to increment or
decrement the reference count respectively. When the reference count falls
to 0, the <a class="link" href="glib-IO-Channels.html#GIOChannel"><span class="type">GIOChannel</span></a> is freed. (Though it isn't closed automatically,
unless it was created using <code class="function">g_io_channel_new_from_file()</code>.)
Using <a class="link" href="glib-IO-Channels.html#g-io-add-watch"><code class="function">g_io_add_watch()</code></a> or <a class="link" href="glib-IO-Channels.html#g-io-add-watch-full"><code class="function">g_io_add_watch_full()</code></a> increments a channel's
reference count.
</p>
<p>
The new functions <a class="link" href="glib-IO-Channels.html#g-io-channel-read-chars"><code class="function">g_io_channel_read_chars()</code></a>, <a class="link" href="glib-IO-Channels.html#g-io-channel-read-line"><code class="function">g_io_channel_read_line()</code></a>,
<a class="link" href="glib-IO-Channels.html#g-io-channel-read-line-string"><code class="function">g_io_channel_read_line_string()</code></a>, <a class="link" href="glib-IO-Channels.html#g-io-channel-read-to-end"><code class="function">g_io_channel_read_to_end()</code></a>,
<a class="link" href="glib-IO-Channels.html#g-io-channel-write-chars"><code class="function">g_io_channel_write_chars()</code></a>, <a class="link" href="glib-IO-Channels.html#g-io-channel-seek-position"><code class="function">g_io_channel_seek_position()</code></a>,
and <a class="link" href="glib-IO-Channels.html#g-io-channel-flush"><code class="function">g_io_channel_flush()</code></a> should not be mixed with the
deprecated functions <a class="link" href="glib-IO-Channels.html#g-io-channel-read"><code class="function">g_io_channel_read()</code></a>, <a class="link" href="glib-IO-Channels.html#g-io-channel-write"><code class="function">g_io_channel_write()</code></a>,
and <a class="link" href="glib-IO-Channels.html#g-io-channel-seek"><code class="function">g_io_channel_seek()</code></a> on the same channel.
</p>
</div>
<div class="refsect1" lang="en">
<a name="id2929359"></a><h2>Details</h2>
<div class="refsect2" lang="en">
<a name="id2929369"></a><h3>
<a name="GIOChannel"></a>GIOChannel</h3>
<a class="indexterm" name="id2929382"></a><pre class="programlisting">typedef struct {
} GIOChannel;
</pre>
<p>
A data structure representing an IO Channel. The fields should be considered
private and should only be accessed with the following functions.
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2929399"></a><h3>
<a name="g-io-channel-unix-new"></a>g_io_channel_unix_new ()</h3>
<a class="indexterm" name="id2929413"></a><pre class="programlisting"><a class="link" href="glib-IO-Channels.html#GIOChannel">GIOChannel</a>*         g_io_channel_unix_new               (int fd);</pre>
<p>
Creates a new <a class="link" href="glib-IO-Channels.html#GIOChannel"><span class="type">GIOChannel</span></a> given a file descriptor.
On UNIX systems this works for plain files, pipes, and sockets.
</p>
<p>
The returned <a class="link" href="glib-IO-Channels.html#GIOChannel"><span class="type">GIOChannel</span></a> has a reference count of 1.
</p>
<p>
The default encoding for <a class="link" href="glib-IO-Channels.html#GIOChannel"><span class="type">GIOChannel</span></a> is UTF-8. If your application
is reading output from a command using via pipe, you may need to
set the encoding to the encoding of the current locale (see
<a class="link" href="glib-Character-Set-Conversion.html#g-get-charset"><code class="function">g_get_charset()</code></a>) with the <a class="link" href="glib-IO-Channels.html#g-io-channel-set-encoding"><code class="function">g_io_channel_set_encoding()</code></a> function.
</p>
<p>
If you want to read raw binary data without interpretation, then
call the <a class="link" href="glib-IO-Channels.html#g-io-channel-set-encoding"><code class="function">g_io_channel_set_encoding()</code></a> function with <a class="link" href="glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> for the
encoding argument.
</p>
<p>
This function is available in GLib on Windows, too, but you should
avoid using it on Windows. The domain of file descriptors and sockets
overlap. There is no way for GLib to know which one you mean in case
the argument you pass to this function happens to be both a valid file
descriptor and socket. If that happens a warning is issued, and GLib
assumes that it is the file descriptor you mean.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>fd</code></em>&#160;:</span></p></td>
<td>a file descriptor.
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></p></td>
<td>a new <a class="link" href="glib-IO-Channels.html#GIOChannel"><span class="type">GIOChannel</span></a>.


</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2929572"></a><h3>
<a name="g-io-channel-unix-get-fd"></a>g_io_channel_unix_get_fd ()</h3>
<a class="indexterm" name="id2929585"></a><pre class="programlisting"><a class="link" href="glib-Basic-Types.html#gint">gint</a>                g_io_channel_unix_get_fd            (<a class="link" href="glib-IO-Channels.html#GIOChannel">GIOChannel</a> *channel);</pre>
<p>
Returns the file descriptor of the <a class="link" href="glib-IO-Channels.html#GIOChannel"><span class="type">GIOChannel</span></a>.
</p>
<p>
On Windows this function returns the file descriptor or socket of the <a class="link" href="glib-IO-Channels.html#GIOChannel"><span class="type">GIOChannel</span></a>.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>channel</code></em>&#160;:</span></p></td>
<td>a <a class="link" href="glib-IO-Channels.html#GIOChannel"><span class="type">GIOChannel</span></a>, created with <a class="link" href="glib-IO-Channels.html#g-io-channel-unix-new"><code class="function">g_io_channel_unix_new()</code></a>.
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></p></td>
<td>the file descriptor of the <a class="link" href="glib-IO-Channels.html#GIOChannel"><span class="type">GIOChannel</span></a>.


</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2929690"></a><h3>
<a name="g-io-channel-win32-new-fd"></a>g_io_channel_win32_new_fd ()</h3>
<a class="indexterm" name="id2929704"></a><pre class="programlisting"><a class="link" href="glib-IO-Channels.html#GIOChannel">GIOChannel</a>*         g_io_channel_win32_new_fd           (<a class="link" href="glib-Basic-Types.html#gint">gint</a> fd);</pre>
<p>
Creates a new <a class="link" href="glib-IO-Channels.html#GIOChannel"><span class="type">GIOChannel</span></a> given a file descriptor on Windows. 
This works for file descriptors from the C runtime.
</p>
<p>
This function works for file descriptors as returned by the <code class="function">open()</code>,
<code class="function">creat()</code>, <code class="function">pipe()</code> and <code class="function">fileno()</code> calls in the Microsoft C runtime. In
order to meaningfully use this function your code should use the same
C runtime as GLib uses, which is msvcrt.dll. Note that in current
Microsoft compilers it is near impossible to convince it to build code
that would use msvcrt.dll. The last Microsoft compiler version that
supported using msvcrt.dll as the C runtime was version 6. The GNU
compiler and toolchain for Windows, also known as Mingw, fully
supports msvcrt.dll.
</p>
<p>
If you have created a <a class="link" href="glib-IO-Channels.html#GIOChannel"><span class="type">GIOChannel</span></a> for a file descriptor and started
watching (polling) it, you shouldn't call <code class="function">read()</code> on the file
descriptor. This is because adding polling for a file descriptor is
implemented in GLib on Windows by starting a thread that sits blocked
in a <code class="function">read()</code> from the file descriptor most of the time. All reads from
the file descriptor should be done by this internal GLib thread. Your
code should call only <a class="link" href="glib-IO-Channels.html#g-io-channel-read"><code class="function">g_io_channel_read()</code></a>.
</p>
<p>
This function is available only in GLib on Windows.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>fd</code></em>&#160;:</span></p></td>
<td>a C library file descriptor.
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></p></td>
<td>a new <a class="link" href="glib-IO-Channels.html#GIOChannel"><span class="type">GIOChannel</span></a>.


</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2927428"></a><h3>
<a name="g-io-channel-win32-new-socket"></a>g_io_channel_win32_new_socket ()</h3>
<a class="indexterm" name="id2927441"></a><pre class="programlisting"><a class="link" href="glib-IO-Channels.html#GIOChannel">GIOChannel</a>*         g_io_channel_win32_new_socket       (<a class="link" href="glib-Basic-Types.html#gint">gint</a> socket);</pre>
<p>
Creates a new <a class="link" href="glib-IO-Channels.html#GIOChannel"><span class="type">GIOChannel</span></a> given a socket on Windows.
</p>
<p>
This function works for sockets created by Winsock. 
It's available only in GLib on Windows.
</p>
<p>
Polling a <a class="link" href="glib-The-Main-Event-Loop.html#GSource"><span class="type">GSource</span></a> created to watch a channel for a socket 
puts the socket in non-blocking mode. This is a side-effect 
of the implementation and unavoidable.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>socket</code></em>&#160;:</span></p></td>