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<html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>The Be Book - Classes And Methods - The Storage Kit</title><link rel="stylesheet" href="be_book.css" type="text/css" media="all" /><link rel="shortcut icon" type="image/vnd.microsoft.icon" href="./images/favicon.ico" /><!--[if IE]>
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<![endif]--><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /><meta name="keywords" content="Access, BeOS, BeBook, API" /><link rel="start" href="index.html" title="The Be Book" /><link rel="up" href="TheStorageKit.html" title="The Storage Kit" /><link rel="prev" href="TheStorageKit_MessageConstants.html" title="Message Constants" /><link rel="next" href="TheSupportKit.html" title="The Support Kit" /></head><body><div id="header"><div id="headerT"><div id="headerTL"><a accesskey="p" href="TheStorageKit_MessageConstants.html" title="Message Constants"><img src="./images/navigation/prev.png" alt="Prev" /></a> <a accesskey="u" href="TheStorageKit.html" title="The Storage Kit"><img src="./images/navigation/up.png" alt="Up" /></a> <a accesskey="n" href="TheSupportKit.html" title="The Support Kit"><img src="./images/navigation/next.png" alt="Next" /></a></div><div id="headerTR"><div id="navigpeople"><a href="http://www.haiku-os.org"><img src="./images/People_24.png" alt="haiku-os.org" title="Visit The Haiku Website" /></a></div><div class="navighome" title="Home"><a accesskey="h" href="index.html"><img src="./images/navigation/home.png" alt="Home" /></a></div><div class="navigboxed" id="navigindex"><a accesskey="i" href="ClassIndex.html" title="Index">I</a></div><div class="navigboxed" id="naviglang" title="English">en</div></div><div id="headerTC">The Be Book - Classes And Methods - The Storage Kit</div></div><div id="headerB">Prev: <a href="TheStorageKit_MessageConstants.html">Message Constants</a>  Up: <a href="TheStorageKit.html">The Storage Kit</a>  Next: <a href="TheSupportKit.html">The Support Kit</a></div><hr /></div><div class="section"><div xmlns="" xmlns:d="http://docbook.org/ns/docbook" class="titlepage"><div><div xmlns:d="http://docbook.org/ns/docbook"><h2 xmlns="http://www.w3.org/1999/xhtml" class="title"><a id="TheStorageKit_DefinedTypes"></a>Defined Types</h2></div></div></div><div class="section"><div xmlns="" xmlns:d="http://docbook.org/ns/docbook" class="titlepage"><div><hr /><div xmlns:d="http://docbook.org/ns/docbook"><h3 xmlns="http://www.w3.org/1999/xhtml" class="title"><a id="attr_info"></a>attr_info</h3></div></div></div><a id="id1266339" class="indexterm"></a><p>
Defined In: <code class="filename">kernel/fs_attr.h</code>
</p><pre class="programlisting definition c">typedef struct <span class="type">attr_info</span>
<span class="type">uint32</span> <code class="varname">type</code>;
<span class="type">off_t</span> <code class="varname">size</code>;
} <span class="type">attr_info</span>;</pre><p>
The <span class="type">attr_info</span> structure contains the following members
</p><table class="variablelist fields"><thead><tr><th>Field</th><th>Description</th></tr></thead><tbody><tr><td><p><span class="term"><code class="varname">type</code></span></p></td><td><p>Is a constant (<code class="constant">B_STRING_TYPE</code>,
<code class="constant">B_INT32_TYPE</code>, etc) that describes
the type of data that the attribute holds.</p></td></tr><tr><td><p><span class="term"><code class="varname">size</code></span></p></td><td><p>Is the size of the attribute's data, in bytes.</p></td></tr></tbody></table></div><div class="section"><div xmlns="" xmlns:d="http://docbook.org/ns/docbook" class="titlepage"><div><hr /><div xmlns:d="http://docbook.org/ns/docbook"><h3 xmlns="http://www.w3.org/1999/xhtml" class="title"><a id="stat"></a>stat</h3></div></div></div><a id="id1266453" class="indexterm"></a><p>
Declared in: <code class="filename">posix/sys/stat.h</code>
</p><p>
The <span class="type">stat</span> structure looks like this:
</p><pre class="programlisting definition cpp">struct stat {
<span class="type">dev_t</span> <code class="varname">st_dev</code>;
<span class="type">ino_t</span> <code class="varname">st_ino</code>;
<span class="type">mode_t</span> <code class="varname">st_mode</code>;
<span class="type">nlink_t</span> <code class="varname">st_nlink</code>;
<span class="type">uid_t</span> <code class="varname">st_uid</code>;
<span class="type">gid_t</span> <code class="varname">st_gid</code>;
<span class="type">off_t</span> <code class="varname">st_size</code>;
<span class="type">dev_t</span> <code class="varname">st_rdev</code>;
<span class="type">size_t</span> <code class="varname">st_blksize</code>;
<span class="type">time_t</span> <code class="varname">st_atime</code>;
<span class="type">time_t</span> <code class="varname">st_mtime</code>;
<span class="type">time_t</span> <code class="varname">st_ctime</code>;
} <span class="type">stat</span>;</pre><p>
And the fields are…
</p><table class="variablelist fields"><thead><tr><th>Field</th><th>Description</th></tr></thead><tbody><tr><td><p><span class="term"><code class="varname">st_dev</code></span></p></td><td><p>Identifies the node's device.</p></td></tr><tr><td><p><span class="term"><code class="varname">st_ino</code></span></p></td><td><p>Is the node's "inode" number.</p></td></tr></tbody></table><p>By combining <code class="varname">st_dev</code> and <code class="varname">st_ino</code>
you can roll your own <span class="type">node_ref</span>:</p><pre class="programlisting example cpp"><span class="type">node_ref</span> <code class="varname">nref</code>;
<span class="type">stat</span> <code class="varname">st</code>;
if (<code class="varname">file</code>.<code class="methodname">GetStat</code>(&amp;<code class="varname">st</code>) == <code class="constant">B_OK</code>) {
<code class="varname">nref.dev</code> = <code class="varname">st.st_dev</code>;
<code class="varname">nref.node</code> = <code class="varname">st.st_ino</code>;
}</pre><p>Meanwhile…</p><table class="variablelist fields"><thead><tr><th>Field</th><th>Description</th></tr></thead><tbody><tr><td><p><span class="term"><code class="varname">st_mode</code></span></p></td><td><p>Describes the node's flavor: plain file, directory or
symbolic link. To test the field, pass it to the
<code class="function">S_ISREG()</code>,
<code class="function">S_ISDIR()</code>,
and <code class="function">S_ISLNK()</code> boolean macros:</p><pre class="programlisting example cpp">if (<code class="function">S_ISREG</code>(<code class="varname">st.st_mode</code>))
<span class="comment">/* it's a "regular" file */</span>
else if (<code class="function">S_ISDIR</code>(<code class="varname">st.st_mode</code>))
<span class="comment">/* it's a directory */</span>
else if (<code class="function">S_ISLNK</code>(<code class="varname">st.st_mode</code>))
<span class="comment">/* it's a symbolic link */</span></pre></td></tr><tr><td><p><span class="term"><code class="varname">st_nlink</code></span></p></td><td><p>Is the number of "hard links" that point to this node.</p></td></tr><tr><td><p><span class="term"><code class="varname">st_uid</code> and <code class="varname">st_gid</code></span></p></td><td><p>Are the user (owner) and group ids that were described in the
<a class="link" href="BStatable.html#BStatable_GetOwner" title="GetOwner(), SetOwner(), GetGroup(), SetGroup(), GetPermissions(), SetPermissions()"><code class="methodname">GetOwner()</code></a>
function.</p></td></tr><tr><td><p><span class="term"><code class="varname">st_rdev</code></span></p></td><td><p>Is, well, no one really knows. It's provided for System V
compatibility (hold your applause), but it's unused.</p></td></tr><tr><td><p><span class="term"><code class="varname">st_blksize</code></span></p></td><td><p>Is the "preferred block size" that's used during copying.
The <span class="application">cp</span> command line program allocates buffers of
this size when it's copying the file's data.</p></td></tr><tr><td><p><span class="term"><code class="varname">st_atime</code>, <code class="varname">st_mtime</code>, and <code class="varname">st_ctime</code></span></p></td><td><p>Are the access, modification, and creation times in seconds since
January 1, 1970. Access time (<code class="varname">st_atime</code>) is currently
unused.</p></td></tr></tbody></table></div><div class="section"><div xmlns="" xmlns:d="http://docbook.org/ns/docbook" class="titlepage"><div><hr /><div xmlns:d="http://docbook.org/ns/docbook"><h3 xmlns="http://www.w3.org/1999/xhtml" class="title"><a id="fs_info"></a>fs_info</h3></div></div></div><a id="id1266899" class="indexterm"></a><p>
The <span class="type">fs_info</span> structure is defined as:
</p><pre class="programlisting definition c">typedef struct <span class="type">fs_info</span> {
<span class="type">dev_t</span> <code class="varname">dev</code>;
<span class="type">ino_t</span> <code class="varname">root</code>;
<span class="type">uint32</span> <code class="varname">flags</code>;
<span class="type">off_t</span> <code class="varname">block_size</code>;
<span class="type">off_t</span> <code class="varname">io_size</code>;
<span class="type">off_t</span> <code class="varname">total_blocks</code>;
<span class="type">off_t</span> <code class="varname">free_blocks</code>;
<span class="type">off_t</span> <code class="varname">total_nodes</code>;
<span class="type">off_t</span> <code class="varname">free_nodes</code>;
<span class="type">char</span> <code class="varname">device_name</code>[128];
<span class="type">char</span> <code class="varname">volume_name</code>[<code class="constant">B_FILE_NAME_LENGTH</code>];
<span class="type">char</span> <code class="varname">fsh_name</code>[<code class="constant">B_OS_NAME_LENGTH</code>];
};</pre><p>
The structure's fields are:
</p><ul class="itemizedlist"><li><p>
<code class="varname">dev</code>. The device number of the device.
</p></li><li><p>
<code class="varname">root</code>. The inode of the root of the device.
</p></li><li><p>
<code class="varname">flags</code>. Flags describing the device's capabilities.
</p></li><li><p>
<code class="varname">block_size</code>. The fundamental block size of the device.
</p></li><li><p>
<code class="varname">io_size</code>. Optimal I/O size of the device.
</p></li><li><p>
<code class="varname">total_blocks</code>. The total number of blocks on the device.
</p></li><li><p>
<code class="varname">free_blocks</code>. The number of free (unused) blocks on the device.
</p></li><li><p>
<code class="varname">total_nodes</code>. The total number of nodes on the device.
</p></li><li><p>
<code class="varname">free_nodes</code>. The number of free (unused) nodes on the device.
</p></li><li><p>
<code class="varname">device_name</code>. Name of the device holding the file system.
</p></li><li><p>
<code class="varname">volume_name</code>. Name of the volume contained by the device.
</p></li><li><p>
<code class="varname">fsh_name</code>. Name of the file system handler for the device.
</p></li></ul><p>
The <code class="varname">flags</code> can be any combination of the following values, which specify
the attributes of the file system on the device:
</p><ul class="itemizedlist"><li><p>
<code class="constant">B_FS_IS_READONLY</code>. The file system on the device is read-only.
</p></li><li><p>
<code class="constant">B_FS_IS_REMOVABLE</code>. The device contains removable media.
</p></li><li><p>
<code class="constant">B_FS_IS_PERSISTENT</code>. Data written to the device remains even while the
device is off.
</p></li><li><p>
<code class="constant">B_FS_IS_SHARED</code>. The file system is being shared on a network.
</p></li><li><p>
<code class="constant">B_FS_HAS_MIME</code>. The file system supports the MIME typing system used
by the BeOS.
</p></li><li><p>
<code class="constant">B_FS_HAS_ATTR</code>. The file system supports node attributes.
</p></li><li><p>
<code class="constant">B_FS_HAS_QUERY</code>. The file system supports the BeOS query mechanism.
</p></li></ul><p>
The information in the <span class="type">fs_info</span> structure is guaranteed to be internally
consistent, but the structure as a whole should be considered to be
out-of-date as soon as you receive it. It provides a picture of a device
as it exists just before the info-retrieving function returns. In
particular, the number of free blocks and of free nodes can easily change
immediately after you receive this information.
</p></div></div><div id="footer"><hr /><div id="footerT">Prev: <a href="TheStorageKit_MessageConstants.html">Message Constants</a>  Up: <a href="TheStorageKit.html">The Storage Kit</a>  Next: <a href="TheSupportKit.html">The Support Kit</a> </div><div id="footerB"><div id="footerBL"><a href="TheStorageKit_MessageConstants.html" title="Message Constants"><img src="./images/navigation/prev.png" alt="Prev" /></a> <a href="TheStorageKit.html" title="The Storage Kit"><img src="./images/navigation/up.png" alt="Up" /></a> <a href="TheSupportKit.html" title="The Support Kit"><img src="./images/navigation/next.png" alt="Next" /></a></div><div id="footerBR"><div><a href="http://www.haiku-os.org"><img src="./images/People_24.png" alt="haiku-os.org" title="Visit The Haiku Website" /></a></div><div class="navighome" title="Home"><a accesskey="h" href="index.html"><img src="./images/navigation/home.png" alt="Home" /></a></div></div><div id="footerBC"><a href="http://www.access-company.com/home.html" title="ACCESS Co."><img alt="Access Company" src="./images/access_logo.png" /></a></div></div></div><div id="licenseFooter"><div id="licenseFooterBL"><a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/" title="Creative Commons License"><img alt="Creative Commons License" style="border-width:0" src="https://licensebuttons.net/l/by-nc-nd/3.0/88x31.png" /></a></div><div id="licenseFooterBR"><a href="./LegalNotice.html">Legal Notice</a></div><div id="licenseFooterBC"><span id="licenseText">This work is licensed under a
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