1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
|
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>db_env_create</title>
<link rel="stylesheet" href="apiReference.css" type="text/css" />
<meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
<link rel="start" href="index.html" title="Berkeley DB C API Reference" />
<link rel="up" href="env.html" title="Chapter 5. The DB_ENV Handle" />
<link rel="prev" href="envclose.html" title="DB_ENV->close()" />
<link rel="next" href="envdbbackup.html" title="DB_ENV->dbbackup()" />
</head>
<body>
<div xmlns="" class="navheader">
<div class="libver">
<p>Library Version 11.2.5.3</p>
</div>
<table width="100%" summary="Navigation header">
<tr>
<th colspan="3" align="center">db_env_create</th>
</tr>
<tr>
<td width="20%" align="left"><a accesskey="p" href="envclose.html">Prev</a> </td>
<th width="60%" align="center">Chapter 5.
The DB_ENV Handle
</th>
<td width="20%" align="right"> <a accesskey="n" href="envdbbackup.html">Next</a></td>
</tr>
</table>
<hr />
</div>
<div class="sect1" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h2 class="title" style="clear: both"><a id="envcreate"></a>db_env_create</h2>
</div>
</div>
</div>
<pre class="programlisting">#include <db.h>
int
db_env_create(DB_ENV **dbenvp, u_int32_t flags); </pre>
<p>
The <code class="function">db_env_create()</code> function creates a <code class="classname">DB_ENV</code>
structure that is the handle for a Berkeley DB environment. This function allocates memory for the structure,
returning a pointer to the structure in the memory to which
<span class="bold"><strong>dbenvp</strong></span> refers. To release the allocated memory and discard the
handle, call the
<a class="xref" href="envclose.html" title="DB_ENV->close()">DB_ENV->close()</a> or
<a class="xref" href="envremove.html" title="DB_ENV->remove()">DB_ENV->remove()</a> methods.
</p>
<p>
<code class="classname">DB_ENV</code> handles are free-threaded if the
<a class="link" href="envopen.html#envopen_DB_THREAD">DB_THREAD</a> flag is specified to the
<a class="xref" href="envopen.html" title="DB_ENV->open()">DB_ENV->open()</a> method when the environment is opened.
The <code class="classname">DB_ENV</code> handle should not be closed while any other handle
remains open that is using it as a reference (for example,
<a class="link" href="db.html" title="Chapter 2. The DB Handle">DB</a> or <a class="link" href="txn.html" title="Chapter 12. The DB_TXN Handle">DB_TXN</a>).
Once either the
<a class="xref" href="envclose.html" title="DB_ENV->close()">DB_ENV->close()</a> or
<a class="xref" href="envremove.html" title="DB_ENV->remove()">DB_ENV->remove()</a>
methods are called, the handle may not be accessed again, regardless of the method's return.
</p>
<p>
Before the handle may be used, you must open it using the
<a class="xref" href="envopen.html" title="DB_ENV->open()">DB_ENV->open()</a>
method.
</p>
<p>
The DB_ENV handle contains a special field, <code class="literal">app_private</code>, which is declared as type
<code class="literal">void *</code>. This field is
provided for the use of the application program. It is initialized to NULL and is not further used by
Berkeley DB in any way.
</p>
<p>
The <code class="function">db_env_create()</code> method returns a non-zero error value on failure and 0 on success.
</p>
<p>
The <span class="bold"><strong>flags</strong></span> parameter must be set to 0.
</p>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idp51271592"></a>Class</h3>
</div>
</div>
</div>
<p>
<a class="link" href="env.html" title="Chapter 5. The DB_ENV Handle">DB_ENV</a>
</p>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idp51313416"></a>See Also</h3>
</div>
</div>
</div>
<p>
<a class="xref" href="env.html#envlist" title="Database Environments and Related Methods">Database Environments and Related Methods</a>
</p>
</div>
</div>
<div class="navfooter">
<hr />
<table width="100%" summary="Navigation footer">
<tr>
<td width="40%" align="left"><a accesskey="p" href="envclose.html">Prev</a> </td>
<td width="20%" align="center">
<a accesskey="u" href="env.html">Up</a>
</td>
<td width="40%" align="right"> <a accesskey="n" href="envdbbackup.html">Next</a></td>
</tr>
<tr>
<td width="40%" align="left" valign="top">DB_ENV->close() </td>
<td width="20%" align="center">
<a accesskey="h" href="index.html">Home</a>
</td>
<td width="40%" align="right" valign="top"> DB_ENV->dbbackup()</td>
</tr>
</table>
</div>
</body>
</html>
|
