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<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>dumper</title><link rel="stylesheet" type="text/css" href="docbook.css"><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot"><link rel="home" href="cygwin-ug-net.html" title="Cygwin User's Guide"><link rel="up" href="using-utils.html" title="Cygwin Utilities"><link rel="prev" href="cygpath.html" title="cygpath"><link rel="next" href="getconf.html" title="getconf"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">dumper</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="cygpath.html">Prev</a> </td><th width="60%" align="center">Cygwin Utilities</th><td width="20%" align="right"> <a accesskey="n" href="getconf.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="dumper"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>dumper — Dump core from WIN32PID to FILENAME.core</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="cmdsynopsis"><p><code class="command">dumper</code> [-n] [-d] [-q] <em class="replaceable"><code>FILENAME</code></em> <em class="replaceable"><code>WIN32PID</code></em> </p></div><div class="cmdsynopsis"><p><code class="command">dumper</code> -h | -V </p></div></div><div class="refsect1"><a name="dumper-options"></a><h2>Options</h2><pre class="screen">
-n, --nokill don't terminate the dumped process
-d, --verbose be verbose while dumping
-h, --help output help information and exit
-q, --quiet be quiet while dumping (default)
-V, --version output version information and exit
</pre></div><div class="refsect1"><a name="dumper-desc"></a><h2>Description</h2><p>The <span class="command"><strong>dumper</strong></span> utility can be used to create a core
dump of running Windows process. This core dump can be later loaded to
<span class="command"><strong>gdb</strong></span> and analyzed. One common way to use
<span class="command"><strong>dumper</strong></span> is to plug it into cygwin's Just-In-Time
debugging facility by adding
</p><pre class="screen">
error_start=x:\path\to\dumper.exe
</pre><p> to the
<span class="emphasis"><em>CYGWIN</em></span> environment variable. Please note that
<code class="literal">x:\path\to\dumper.exe</code> is Windows-style and not cygwin
path. If <code class="literal">error_start</code> is set this way, then dumper will
be started whenever some program encounters a fatal error. </p><p> <span class="command"><strong>dumper</strong></span> can be also be started from the command
line to create a core dump of any running process.</p><p>For historical reasons, unless the <code class="literal">-n</code> option
is given, after the core dump is created and when the
<span class="command"><strong>dumper</strong></span> exits, the target process is also
terminated.</p><p> To save space in the core dump, <span class="command"><strong>dumper</strong></span> doesn't
write those portions of the target process's memory space that are loaded
from executable and dll files and are unchanged (e.g. program code).
Instead, <span class="command"><strong>dumper</strong></span> saves paths to the files which
contain that data. When a core dump is loaded into gdb, it uses these
paths to load the appropriate files. That means that if you create a core
dump on one machine and try to debug it on another, you'll need to place
identical copies of the executable and dlls in the same directories as on
the machine where the core dump was created. </p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="cygpath.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="using-utils.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="getconf.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">cygpath </td><td width="20%" align="center"><a accesskey="h" href="cygwin-ug-net.html">Home</a></td><td width="40%" align="right" valign="top"> getconf</td></tr></table></div></body></html>