1<!--$Id: db_fd.so,v 10.31 2005/06/14 14:06:57 bostic Exp $--> 2<!--Copyright (c) 1997,2008 Oracle. All rights reserved.--> 3<!--See the file LICENSE for redistribution information.--> 4<html> 5<head> 6<title>Berkeley DB: DB->fd</title> 7<meta name="description" content="Berkeley DB: An embedded database programmatic toolkit."> 8<meta name="keywords" content="embedded,database,programmatic,toolkit,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++"> 9</head> 10<body bgcolor=white> 11<table width="100%"><tr valign=top> 12<td> 13<b>DB->fd</b> 14</td> 15<td align=right> 16<a href="../api_c/api_core.html"><img src="../images/api.gif" alt="API"></a> 17<a href="../ref/toc.html"><img src="../images/ref.gif" alt="Ref"></a></td> 18</tr></table> 19<hr size=1 noshade> 20<tt> 21<b><pre> 22#include <db.h> 23<p> 24int 25DB->fd(DB *db, int *fdp); 26</pre></b> 27<hr size=1 noshade> 28<b>Description: DB->fd</b> 29<p>The DB->fd method provides access to a file descriptor representative 30of the underlying database. A file descriptor referring to the same 31file will be returned to all processes that call <a href="../api_c/db_open.html">DB->open</a> with 32the same <b>file</b> parameter.</p> 33<p>This file descriptor may be safely used as a parameter to the 34<b>fcntl</b>(2) and <b>flock</b>(2) locking functions.</p> 35<p>The DB->fd method only supports a coarse-grained form of locking. 36Applications should instead use the Berkeley DB lock manager where possible.</p> 37<p>The DB->fd method 38returns a non-zero error value on failure 39and 0 on success. 40</p> 41<b>Parameters</b> <br> 42 <b>fdp</b><ul compact><li>The <b>fdp</b> parameter references memory into which 43 the current file descriptor is copied.</ul> 44<br> 45<hr size=1 noshade> 46<br><b>Class</b> 47<a href="../api_c/db_class.html">DB</a> 48<br><b>See Also</b> 49<a href="../api_c/db_list.html">Databases and Related Methods</a> 50</tt> 51<table width="100%"><tr><td><br></td><td align=right> 52<a href="../api_c/api_core.html"><img src="../images/api.gif" alt="API"></a><a href="../ref/toc.html"><img src="../images/ref.gif" alt="Ref"></a> 53</td></tr></table> 54<p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> 55</body> 56</html> 57
