rpm/db/docs/api_c/db_fd.html

93 lines
4.6 KiB
HTML

<!--$Id: db_fd.so,v 10.21 2000/03/01 21:41:28 bostic Exp $-->
<!--Copyright 1997, 1998, 1999, 2000 by Sleepycat Software, Inc.-->
<!--All rights reserved.-->
<html>
<head>
<title>Berkeley DB: DB-&gt;fd</title>
<meta name="description" content="Berkeley DB: An embedded database programmatic toolkit.">
<meta name="keywords" content="embedded,database,programmatic,toolkit,b+tree,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,java,C,C++">
</head>
<body bgcolor=white>
<a name="2"><!--meow--></a>
<table><tr valign=top>
<td>
<h1>DB-&gt;fd</h1>
</td>
<td width="1%">
<a href="../api_c/c_index.html"><img src="../images/api.gif" alt="API"></a><a href="../ref/toc.html"><img src="../images/ref.gif" alt="Ref"></a>
</td></tr></table>
<hr size=1 noshade>
<tt>
<h3><pre>
#include &lt;db.h&gt;
<p>
int
DB-&gt;fd(DB *db, int *fdp);
</pre></h3>
<h1>Description</h1>
<p>The DB-&gt;fd function
copies a file descriptor representative of the underlying database into
the memory referenced by <b>fdp</b>. A file descriptor referencing the
same file will be returned to all processes that call <a href="../api_c/db_open.html">DB-&gt;open</a> with
the same <b>file</b> argument. This file descriptor may be safely used
as an argument to the <b>fcntl</b>(2) and <b>flock</b>(2) locking
functions. The file descriptor is not necessarily associated with any of
the underlying files actually used by the access method.
<p>The DB-&gt;fd function only supports a coarse-grained form of locking.
Applications should use the lock manager where possible.
<p>The DB-&gt;fd function returns a non-zero error value on failure and 0 on success.
<h1>Errors</h1>
<p>The DB-&gt;fd function may fail and return a non-zero error for errors specified for other Berkeley DB and C library or system functions.
If a catastrophic error has occurred, the DB-&gt;fd function may fail and return
<a href="../ref/program/errorret.html#DB_RUNRECOVERY">DB_RUNRECOVERY</a>, in which case all subsequent Berkeley DB calls will fail
in the same way.
<h1>See Also</h1>
<a href="../api_c/db_create.html">db_create</a>,
<a href="../api_c/db_close.html">DB-&gt;close</a>,
<a href="../api_c/db_cursor.html">DB-&gt;cursor</a>,
<a href="../api_c/db_del.html">DB-&gt;del</a>,
<a href="../api_c/db_err.html">DB-&gt;err</a>,
<a href="../api_c/db_fd.html">DB-&gt;fd</a>,
<a href="../api_c/db_get.html">DB-&gt;get</a>,
<a href="../api_c/db_get_byteswapped.html">DB-&gt;get_byteswapped</a>,
<a href="../api_c/db_get_type.html">DB-&gt;get_type</a>,
<a href="../api_c/db_join.html">DB-&gt;join</a>,
<a href="../api_c/db_key_range.html">DB-&gt;key_range</a>,
<a href="../api_c/db_open.html">DB-&gt;open</a>,
<a href="../api_c/db_put.html">DB-&gt;put</a>,
<a href="../api_c/db_remove.html">DB-&gt;remove</a>,
<a href="../api_c/db_set_bt_compare.html">DB-&gt;set_bt_compare</a>,
<a href="../api_c/db_set_bt_minkey.html">DB-&gt;set_bt_minkey</a>,
<a href="../api_c/db_set_bt_prefix.html">DB-&gt;set_bt_prefix</a>,
<a href="../api_c/db_set_cachesize.html">DB-&gt;set_cachesize</a>,
<a href="../api_c/db_set_dup_compare.html">DB-&gt;set_dup_compare</a>,
<a href="../api_c/db_set_errcall.html">DB-&gt;set_errcall</a>,
<a href="../api_c/db_set_errfile.html">DB-&gt;set_errfile</a>,
<a href="../api_c/db_set_errpfx.html">DB-&gt;set_errpfx</a>,
<a href="../api_c/db_set_flags.html">DB-&gt;set_flags</a>,
<a href="../api_c/db_set_h_ffactor.html">DB-&gt;set_h_ffactor</a>,
<a href="../api_c/db_set_h_hash.html">DB-&gt;set_h_hash</a>,
<a href="../api_c/db_set_h_nelem.html">DB-&gt;set_h_nelem</a>,
<a href="../api_c/db_set_lorder.html">DB-&gt;set_lorder</a>,
<a href="../api_c/db_set_malloc.html">DB-&gt;set_malloc</a>,
<a href="../api_c/db_set_pagesize.html">DB-&gt;set_pagesize</a>,
<a href="../api_c/db_set_paniccall.html">DB-&gt;set_paniccall</a>,
<a href="../api_c/db_set_q_extentsize.html">DB-&gt;set_q_extentsize</a>,
<a href="../api_c/db_set_realloc.html">DB-&gt;set_realloc</a>,
<a href="../api_c/db_set_re_delim.html">DB-&gt;set_re_delim</a>,
<a href="../api_c/db_set_re_len.html">DB-&gt;set_re_len</a>,
<a href="../api_c/db_set_re_pad.html">DB-&gt;set_re_pad</a>,
<a href="../api_c/db_set_re_source.html">DB-&gt;set_re_source</a>,
<a href="../api_c/db_stat.html">DB-&gt;stat</a>,
<a href="../api_c/db_sync.html">DB-&gt;sync</a>,
<a href="../api_c/db_upgrade.html">DB-&gt;upgrade</a>
and
<a href="../api_c/db_verify.html">DB-&gt;verify</a>.
</tt>
<table><tr><td><br></td><td width="1%">
<a href="../api_c/c_index.html"><img src="../images/api.gif" alt="API"></a><a href="../ref/toc.html"><img src="../images/ref.gif" alt="Ref"></a>
</td></tr></table>
<p><font size=1><a href="http://www.sleepycat.com">Copyright Sleepycat Software</a></font>
</body>
</html>