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diff --git a/gcc-4.4.3/libstdc++-v3/doc/html/manual/ext_io.html b/gcc-4.4.3/libstdc++-v3/doc/html/manual/ext_io.html new file mode 100644 index 000000000..f79e3275d --- /dev/null +++ b/gcc-4.4.3/libstdc++-v3/doc/html/manual/ext_io.html @@ -0,0 +1,51 @@ +<?xml version="1.0" encoding="UTF-8" standalone="no"?> +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> +<html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>Chapter 38. Input and Output</title><meta name="generator" content="DocBook XSL Stylesheets V1.74.0" /><meta name="keywords" content=" ISO C++ , library " /><link rel="home" href="../spine.html" title="The GNU C++ Library Documentation" /><link rel="up" href="extensions.html" title="Part XII. Extensions" /><link rel="prev" href="ext_iterators.html" title="Chapter 37. Iterators" /><link rel="next" href="ext_demangling.html" title="Chapter 39. Demangling" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter 38. Input and Output</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ext_iterators.html">Prev</a> </td><th width="60%" align="center">Part XII. + Extensions + +</th><td width="20%" align="right"> <a accesskey="n" href="ext_demangling.html">Next</a></td></tr></table><hr /></div><div class="chapter" lang="en" xml:lang="en"><div class="titlepage"><div><div><h2 class="title"><a id="manual.ext.io"></a>Chapter 38. Input and Output</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="ext_io.html#manual.ext.io.filebuf_derived">Derived filebufs</a></span></dt></dl></div><p> + Extensions allowing <code class="code">filebuf</code>s to be constructed from + "C" types like FILE*s and file descriptors. + </p><div class="sect1" lang="en" xml:lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="manual.ext.io.filebuf_derived"></a>Derived filebufs</h2></div></div></div><p>The v2 library included non-standard extensions to construct + <code class="code">std::filebuf</code>s from C stdio types such as + <code class="code">FILE*</code>s and POSIX file descriptors. + Today the recommended way to use stdio types with libstdc++ + IOStreams is via the <code class="code">stdio_filebuf</code> class (see below), + but earlier releases provided slightly different mechanisms. + </p><div class="itemizedlist"><ul type="disc"><li><p>3.0.x <code class="code">filebuf</code>s have another ctor with this signature: + <code class="code">basic_filebuf(__c_file_type*, ios_base::openmode, int_type); + </code> + This comes in very handy in a number of places, such as + attaching Unix sockets, pipes, and anything else which uses file + descriptors, into the IOStream buffering classes. The three + arguments are as follows: + </p><div class="itemizedlist"><ul type="circle"><li><p><code class="code">__c_file_type* F </code> + // the __c_file_type typedef usually boils down to stdio's FILE + </p></li><li><p><code class="code">ios_base::openmode M </code> + // same as all the other uses of openmode + </p></li><li><p><code class="code">int_type B </code> + // buffer size, defaults to BUFSIZ if not specified + </p></li></ul></div><p> + For those wanting to use file descriptors instead of FILE*'s, I + invite you to contemplate the mysteries of C's <code class="code">fdopen()</code>. + </p></li><li><p>In library snapshot 3.0.95 and later, <code class="code">filebuf</code>s bring + back an old extension: the <code class="code">fd()</code> member function. The + integer returned from this function can be used for whatever file + descriptors can be used for on your platform. Naturally, the + library cannot track what you do on your own with a file descriptor, + so if you perform any I/O directly, don't expect the library to be + aware of it. + </p></li><li><p>Beginning with 3.1, the extra <code class="code">filebuf</code> constructor and + the <code class="code">fd()</code> function were removed from the standard + filebuf. Instead, <code class="code"><ext/stdio_filebuf.h></code> contains + a derived class called + <a class="ulink" href="http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/class____gnu__cxx_1_1stdio__filebuf.html" target="_top"><code class="code">__gnu_cxx::stdio_filebuf</code></a>. + This class can be constructed from a C <code class="code">FILE*</code> or a file + descriptor, and provides the <code class="code">fd()</code> function. + </p></li></ul></div><p>If you want to access a <code class="code">filebuf</code>'s file descriptor to + implement file locking (e.g. using the <code class="code">fcntl()</code> system + call) then you might be interested in Henry Suter's + <a class="ulink" href="http://suter.home.cern.ch/suter/RWLock.html" target="_top">RWLock</a> + class. + </p><p> + </p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ext_iterators.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="extensions.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="ext_demangling.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 37. 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