<!--$Id: db_fd.so,v 10.31 2005/06/14 14:06:57 bostic Exp $--> <!--Copyright (c) 1997,2008 Oracle. All rights reserved.--> <!--See the file LICENSE for redistribution information.--> <html> <head> <title>Berkeley DB: Db::fd</title> <meta name="description" content="Berkeley DB: An embedded database programmatic toolkit."> <meta name="keywords" content="embedded,database,programmatic,toolkit,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++"> </head> <body bgcolor=white> <table width="100%"><tr valign=top> <td> <b>Db::fd</b> </td> <td align=right> <a href="../api_cxx/api_core.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> <b><pre> #include <db_cxx.h> <p> int Db::fd(int *fdp); </pre></b> <hr size=1 noshade> <b>Description: Db::fd</b> <p>The Db::fd method provides access to a file descriptor representative of the underlying database. A file descriptor referring to the same file will be returned to all processes that call <a href="../api_cxx/db_open.html">Db::open</a> with the same <b>file</b> parameter.</p> <p>This file descriptor may be safely used as a parameter to the <b>fcntl</b>(2) and <b>flock</b>(2) locking functions.</p> <p>The Db::fd method only supports a coarse-grained form of locking. Applications should instead use the Berkeley DB lock manager where possible.</p> <p>The Db::fd method either returns a non-zero error value or throws an exception that encapsulates a non-zero error value on failure, and returns 0 on success. </p> <b>Parameters</b> <br> <b>fdp</b><ul compact><li>The <b>fdp</b> parameter references memory into which the current file descriptor is copied.</ul> <br> <hr size=1 noshade> <br><b>Class</b> <a href="../api_cxx/db_class.html">Db</a> <br><b>See Also</b> <a href="../api_cxx/db_list.html">Databases and Related Methods</a> </tt> <table width="100%"><tr><td><br></td><td align=right> <a href="../api_cxx/api_core.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>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> </body> </html>