1<!--$Id: set_func_seek.so,v 10.19 2004/09/20 14:29:50 mjc 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_env_set_func_seek</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_env_set_func_seek</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_env_set_func_seek(int (*func_seek)(int fd, off_t offset, int whence)); 26</pre></b> 27<hr size=1 noshade> 28<b>Description: db_env_set_func_seek</b> 29<p>The Berkeley DB library requires the ability to specify that a subsequent read 30from or write to a file will occur at a specific location in that file.</p> 31<p>The db_env_set_func_seek method configures all operations performed by a process and 32all of its threads of control, not operations confined to a single 33database environment.</p> 34<p>Although the db_env_set_func_seek method may be called at any time during the life of 35the application, it should normally be called before making calls to the 36<a href="/api_c/env_class.html">db_env_create</a> or <a href="/api_c/db_class.html">db_create</a> methods.</p> 37<p>The db_env_set_func_seek method 38returns a non-zero error value on failure 39and 0 on success. 40</p> 41<b>Parameters</b> <br> 42 <b>func_seek</b><ul compact><li>The <b>func_seek</b> parameter is the function which seeks to a specific 43location in a file. 44<p>The <b>fd</b> parameter is an open file descriptor on the file.</p> 45<p>The <b>seek</b> function must cause a subsequent read from or write to 46the file to occur at the byte offset specified by the <b>offset</b> 47parameter.</p> 48<p>The <b>whence</b> parameter specifies where in the file the byte offset 49is relative to, as described by the IEEE/ANSI Std 1003.1 (POSIX) <b>lseek</b> system 50call.</p> 51<p>The <b>func_seek</b> function must return the value of <b>errno</b> on 52failure and 0 on success.</p></ul> 53<br> 54<br><b>See Also</b> 55<a href="/ref/program/runtime.html">Run-time configuration</a> 56</tt> 57<table width="100%"><tr><td><br></td><td align=right> 58<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> 59</td></tr></table> 60<p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> 61</body> 62</html> 63