docs/api_reference/C/db_env_set_func_ftruncate.html

   1 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
   2 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
   3 <html xmlns="http://www.w3.org/1999/xhtml">
   4   <head>
   5     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
   6     <title>db_env_set_func_ftruncate</title>
   7     <link rel="stylesheet" href="apiReference.css" type="text/css" />
   8     <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
   9     <link rel="start" href="index.html" title="Berkeley DB C API Reference" />
  10     <link rel="up" href="setfunc.html" title="Appendix C.  Berkeley DB Application Space Static Functions" />
  11     <link rel="prev" href="db_env_set_func_fsync.html" title="db_env_set_func_fsync" />
  12     <link rel="next" href="db_env_set_func_ioinfo.html" title="db_env_set_func_ioinfo" />
  13   </head>
  14   <body>
  15     <div xmlns="" class="navheader">
  16       <div class="libver">
  17         <p>Library Version 11.2.5.3</p>
  18       </div>
  19       <table width="100%" summary="Navigation header">
  20         <tr>
  21           <th colspan="3" align="center">db_env_set_func_ftruncate</th>
  22         </tr>
  23         <tr>
  24           <td width="20%" align="left"><a accesskey="p" href="db_env_set_func_fsync.html">Prev</a> </td>
  25           <th width="60%" align="center">Appendix C.
  26                 Berkeley DB Application Space Static Functions
  27         </th>
  28           <td width="20%" align="right"> <a accesskey="n" href="db_env_set_func_ioinfo.html">Next</a></td>
  29         </tr>
  30       </table>
  31       <hr />
  32     </div>
  33     <div class="sect1" lang="en" xml:lang="en">
  34       <div class="titlepage">
  35         <div>
  36           <div>
  37             <h2 class="title" style="clear: both"><a id="db_env_set_func_ftruncate"></a>db_env_set_func_ftruncate</h2>
  38           </div>
  39         </div>
  40       </div>
  41       <pre class="programlisting">#include &lt;db.h&gt;
  42
  43 int
  44 db_env_set_func_ftruncate(int (*func_ftruncate)(int fd, off_t offset)); </pre>
  45       <p>
  46          The Berkeley DB library requires the ability to truncate a file.
  47     </p>
  48       <p>
  49          The <code class="function">db_env_set_func_ftruncate</code> function configures all operations
  50          performed by a process and all of its threads of control, not
  51          operations confined to a single database environment.
  52     </p>
  53       <p>
  54          Although the <code class="function">db_env_set_func_ftruncate</code> function may be called at any
  55          time during the life of the application, it should normally be called
  56          before making calls to the <a class="xref" href="envcreate.html" title="db_env_create">db_env_create</a> or
  57          <a class="xref" href="dbcreate.html" title="db_create">db_create</a> methods.
  58     </p>
  59       <p>
  60          The <code class="function">db_env_set_func_ftruncate()</code> <span>
  61                   function returns a non-zero error value on failure and 0 on success.
  62             </span>
  63     </p>
  64       <div class="sect2" lang="en" xml:lang="en">
  65         <div class="titlepage">
  66           <div>
  67             <div>
  68               <h3 class="title"><a id="idp63587448"></a>Parameters</h3>
  69             </div>
  70           </div>
  71         </div>
  72         <div class="sect3" lang="en" xml:lang="en">
  73           <div class="titlepage">
  74             <div>
  75               <div>
  76                 <h4 class="title"><a id="idp63587640"></a>func_ftruncate</h4>
  77               </div>
  78             </div>
  79           </div>
  80           <p>
  81                           The <span class="bold"><strong>func_ftruncate</strong></span> parameter is the
  82                           function which truncates a file.
  83                       </p>
  84           <p>
  85                           The <span class="bold"><strong>fd</strong></span> parameter is an open file
  86                           descriptor on the file.
  87                      </p>
  88           <p>
  89                           The <span class="bold"><strong>ftruncate</strong></span> function must truncate
  90                           the file to the byte length specified by the <span class="bold"><strong>offset</strong></span> parameter.
  91                      </p>
  92           <p>
  93                           The <span class="bold"><strong>func_ftruncate</strong></span> function must
  94                           return the value of <span class="bold"><strong>errno</strong></span> on failure
  95                           and 0 on success.
  96                      </p>
  97         </div>
  98       </div>
  99       <div class="sect2" lang="en" xml:lang="en">
 100         <div class="titlepage">
 101           <div>
 102             <div>
 103               <h3 class="title"><a id="idp63585200"></a>See Also</h3>
 104             </div>
 105           </div>
 106         </div>
 107         <p>
 108           <a href="../../programmer_reference/program_runtime.html" class="olink">Run-time configuration</a>
 109      </p>
 110       </div>
 111     </div>
 112     <div class="navfooter">
 113       <hr />
 114       <table width="100%" summary="Navigation footer">
 115         <tr>
 116           <td width="40%" align="left"><a accesskey="p" href="db_env_set_func_fsync.html">Prev</a> </td>
 117           <td width="20%" align="center">
 118             <a accesskey="u" href="setfunc.html">Up</a>
 119           </td>
 120           <td width="40%" align="right"> <a accesskey="n" href="db_env_set_func_ioinfo.html">Next</a></td>
 121         </tr>
 122         <tr>
 123           <td width="40%" align="left" valign="top">db_env_set_func_fsync </td>
 124           <td width="20%" align="center">
 125             <a accesskey="h" href="index.html">Home</a>
 126           </td>
 127           <td width="40%" align="right" valign="top"> db_env_set_func_ioinfo</td>
 128         </tr>
 129       </table>
 130     </div>
 131   </body>
 132 </html>