<?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_dump</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="utilities.html" title="Appendix 1. Berkeley DB Command Line Utilities" /> <link rel="prev" href="db_deadlock.html" title="db_deadlock" /> <link rel="next" href="db_hotbackup.html" title="db_hotbackup" /> </head> <body> <div class="navheader"> <table width="100%" summary="Navigation header"> <tr> <th colspan="3" align="center">db_dump</th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="db_deadlock.html">Prev</a> </td> <th width="60%" align="center">Appendix 1. Berkeley DB Command Line Utilities </th> <td width="20%" align="right"> <a accesskey="n" href="db_hotbackup.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="db_dump"></a>db_dump</h2> </div> </div> </div> <pre class="programlisting">db_dump [-klNpRrV] [-d ahr] [-f output] [-h home] [-P password] [-s database] file db_dump [-kNpV] [-d ahr] [-f output] [-h home] -m database db_dump185 [-p] [-f output] file </pre> <p> The <span class="command"><strong>db_dump</strong></span> utility reads the database file <span class="bold"><strong>file</strong></span> and writes it to the standard output using a portable flat-text format understood by the <a class="xref" href="db_load.html" title="db_load">db_load</a> utility. The <span class="bold"><strong>file</strong></span> argument must be a file produced using the Berkeley DB library functions. </p> <p> The <span class="command"><strong>db_dump185</strong></span> utility is similar to the <span class="command"><strong>db_dump</strong></span> utility, except that it reads databases in the format used by Berkeley DB versions 1.85 and 1.86. </p> <p> The options are as follows: </p> <div class="itemizedlist"> <ul type="disc"> <li> <p> <span class="bold"><strong>-d</strong></span> </p> <p> Dump the specified database in a format helpful for debugging the Berkeley DB library routines. </p> <div class="itemizedlist"> <ul type="circle"> <li> <p> <span class="bold"><strong>a</strong></span> </p> <p> Display all information. </p> </li> <li> <p> <span class="bold"><strong>h</strong></span> </p> <p> Display only page headers. </p> </li> <li> <p> <span class="bold"><strong>r</strong></span> </p> <p> Do not display the free-list or pages on the free list. This mode is used by the recovery tests. </p> </li> </ul> </div> <p> <span class="bold"><strong>The output format of the <span class="bold"><strong>-d</strong></span> option is not standard and may change, without notice, between releases of the Berkeley DB library.</strong></span> </p> </li> <li> <p> <span class="bold"><strong>-f</strong></span> </p> <p> Write to the specified file instead of to the standard output. </p> </li> <li> <p> <span class="bold"><strong>-h</strong></span> </p> <p> Specify a home directory for the database environment; by default, the current working directory is used. </p> </li> <li> <p> <span class="bold"><strong>-k</strong></span> </p> <p> Dump record numbers from Queue and Recno databases as keys. </p> </li> <li> <p> <span class="bold"><strong>-l</strong></span> </p> <p> List the databases stored in the file. </p> </li> <li> <p> <span class="bold"><strong>-m</strong></span> </p> <p> Specify a named in-memory database to dump. In this case the <span class="bold"><strong>file</strong></span> argument must be omitted. </p> </li> <li> <p> <span class="bold"><strong>-N</strong></span> </p> <p> Do not acquire shared region mutexes while running. Other problems, such as potentially fatal errors in Berkeley DB, will be ignored as well. This option is intended only for debugging errors, and should not be used under any other circumstances. </p> </li> <li> <p> <span class="bold"><strong>-P</strong></span> </p> <p> Specify an environment password. Although Berkeley DB utilities overwrite password strings as soon as possible, be aware there may be a window of vulnerability on systems where unprivileged users can see command-line arguments or where utilities are not able to overwrite the memory containing the command-line arguments. </p> </li> <li> <p> <span class="bold"><strong>-p</strong></span> </p> <p> If characters in either the key or data items are printing characters (as defined by <span class="bold"><strong>isprint</strong></span>(3)), use printing characters in <span class="bold"><strong>file</strong></span> to represent them. This option permits users to use standard text editors and tools to modify the contents of databases. </p> <p> Note: different systems may have different notions about what characters are considered <span class="emphasis"><em>printing characters</em></span>, and databases dumped in this manner may be less portable to external systems. </p> </li> <li> <p> <span class="bold"><strong>-R</strong></span> </p> <p> Aggressively salvage data from a possibly corrupt file. The <span class="bold"><strong>-R</strong></span> flag differs from the <span class="bold"><strong>-r</strong></span> option in that it will return all possible data from the file at the risk of also returning already deleted or otherwise nonsensical items. Data dumped in this fashion will almost certainly have to be edited by hand or other means before the data is ready for reload into another database </p> </li> <li> <p> <span class="bold"><strong>-r</strong></span> </p> <p> Salvage data from a possibly corrupt file. When used on a uncorrupted database, this option should return equivalent data to a normal dump, but most likely in a different order. </p> </li> <li> <p> <span class="bold"><strong>-s</strong></span> </p> <p> Specify a single database to dump. If no database is specified, all databases in the database file are dumped. </p> </li> <li> <p> <span class="bold"><strong>-V</strong></span> </p> <p> Write the library version number to the standard output, and exit. </p> </li> </ul> </div> <p> Dumping and reloading Hash databases that use user-defined hash functions will result in new databases that use the default hash function. Although using the default hash function may not be optimal for the new database, it will continue to work correctly. </p> <p> Dumping and reloading Btree databases that use user-defined prefix or comparison functions will result in new databases that use the default prefix and comparison functions. <span class="bold"><strong>In this case, it is quite likely that the database will be damaged beyond repair permitting neither record storage or retrieval.</strong></span> </p> <p> The only available workaround for either case is to modify the sources for the <a class="xref" href="db_load.html" title="db_load">db_load</a> utility to load the database using the correct hash, prefix, and comparison functions. </p> <p> The <span class="command"><strong>db_dump185</strong></span> utility may not be available on your system because it is not always built when the Berkeley DB libraries and utilities are installed. If you are unable to find it, see your system administrator for further information. </p> <p> The <span class="command"><strong>db_dump</strong></span> and <span class="command"><strong>db_dump185</strong></span> utility output formats are documented in the <a href="../../programmer_reference/dumpload_format.html" class="olink">Dump Output Formats</a> section of the Berkeley DB Reference Guide. </p> <p> The <span class="command"><strong>db_dump</strong></span> utility may be used with a Berkeley DB environment (as described for the <span class="bold"><strong>-h</strong></span> option, the environment variable <span class="bold"><strong>DB_HOME</strong></span>, or because the utility was run in a directory containing a Berkeley DB environment). In order to avoid environment corruption when using a Berkeley DB environment, <span class="command"><strong>db_dump</strong></span> should always be given the chance to detach from the environment and exit gracefully. To cause <span class="command"><strong>db_dump</strong></span> to release all environment resources and exit cleanly, send it an interrupt signal (SIGINT). </p> <p> Even when using a Berkeley DB database environment, the db_dump utility does not use any kind of database locking if it is invoked with the <span class="bold"><strong>-d</strong></span>, <span class="bold"><strong>-R</strong></span>, or <span class="bold"><strong>-r</strong></span> arguments. If used with one of these arguments, the <span class="command"><strong>db_dump</strong></span> utility may only be safely run on databases that are not being modified by any other process; otherwise, the output may be corrupt. </p> <p> The <span class="command"><strong>db_dump</strong></span> utility exits 0 on success, and >0 if an error occurs. </p> <p> The <span class="command"><strong>db_dump185</strong></span> utility exits 0 on success, and >0 if an error occurs. </p> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="id1717453"></a>Environment Variables</h3> </div> </div> </div> <div class="sect3" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h4 class="title"><a id="id1718179"></a>DB_HOME</h4> </div> </div> </div> <p> If the <span class="bold"><strong>-h</strong></span> option is not specified and the environment variable DB_HOME is set, it is used as the path of the database home, as described in the <a class="xref" href="envopen.html" title="DbEnv::open()">DbEnv::open()</a> method. </p> </div> </div> </div> <div class="navfooter"> <hr /> <table width="100%" summary="Navigation footer"> <tr> <td width="40%" align="left"><a accesskey="p" href="db_deadlock.html">Prev</a> </td> <td width="20%" align="center"> <a accesskey="u" href="utilities.html">Up</a> </td> <td width="40%" align="right"> <a accesskey="n" href="db_hotbackup.html">Next</a></td> </tr> <tr> <td width="40%" align="left" valign="top">db_deadlock </td> <td width="20%" align="center"> <a accesskey="h" href="index.html">Home</a> </td> <td width="40%" align="right" valign="top"> db_hotbackup</td> </tr> </table> </div> </body> </html>