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<title>GDB/MI Simple Examples (Debugging with GDB)</title>
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<a name="GDB_002fMI-Simple-Examples"></a>
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<p>
Next: <a href="GDB_002fMI-Command-Description-Format.html#GDB_002fMI-Command-Description-Format" accesskey="n" rel="next">GDB/MI Command Description Format</a>, Previous: <a href="GDB_002fMI-Output-Records.html#GDB_002fMI-Output-Records" accesskey="p" rel="prev">GDB/MI Output Records</a>, Up: <a href="GDB_002fMI.html#GDB_002fMI" accesskey="u" rel="up">GDB/MI</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
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<hr>
<a name="Simple-Examples-of-GDB_002fMI-Interaction"></a>
<h3 class="section">27.6 Simple Examples of <small>GDB/MI</small> Interaction</h3>
<a name="index-GDB_002fMI_002c-simple-examples"></a>
<p>This subsection presents several simple examples of interaction using
the <small>GDB/MI</small> interface. In these examples, ‘<samp>-></samp>’ means that the
following line is passed to <small>GDB/MI</small> as input, while ‘<samp><-</samp>’ means
the output received from <small>GDB/MI</small>.
</p>
<p>Note the line breaks shown in the examples are here only for
readability, they don’t appear in the real output.
</p>
<a name="Setting-a-Breakpoint"></a>
<h4 class="subheading">Setting a Breakpoint</h4>
<p>Setting a breakpoint generates synchronous output which contains detailed
information of the breakpoint.
</p>
<div class="smallexample">
<pre class="smallexample">-> -break-insert main
<- ^done,bkpt={number="1",type="breakpoint",disp="keep",
enabled="y",addr="0x08048564",func="main",file="myprog.c",
fullname="/home/nickrob/myprog.c",line="68",thread-groups=["i1"],
times="0"}
<- (gdb)
</pre></div>
<a name="Program-Execution"></a>
<h4 class="subheading">Program Execution</h4>
<p>Program execution generates asynchronous records and MI gives the
reason that execution stopped.
</p>
<div class="smallexample">
<pre class="smallexample">-> -exec-run
<- ^running
<- (gdb)
<- *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",thread-id="0",
frame={addr="0x08048564",func="main",
args=[{name="argc",value="1"},{name="argv",value="0xbfc4d4d4"}],
file="myprog.c",fullname="/home/nickrob/myprog.c",line="68",
arch="i386:x86_64"}
<- (gdb)
-> -exec-continue
<- ^running
<- (gdb)
<- *stopped,reason="exited-normally"
<- (gdb)
</pre></div>
<a name="Quitting-GDB-2"></a>
<h4 class="subheading">Quitting <small>GDB</small></h4>
<p>Quitting <small>GDB</small> just prints the result class ‘<samp>^exit</samp>’.
</p>
<div class="smallexample">
<pre class="smallexample">-> (gdb)
<- -gdb-exit
<- ^exit
</pre></div>
<p>Please note that ‘<samp>^exit</samp>’ is printed immediately, but it might
take some time for <small>GDB</small> to actually exit. During that time, <small>GDB</small>
performs necessary cleanups, including killing programs being debugged
or disconnecting from debug hardware, so the frontend should wait till
<small>GDB</small> exits and should only forcibly kill <small>GDB</small> if it
fails to exit in reasonable time.
</p>
<a name="A-Bad-Command"></a>
<h4 class="subheading">A Bad Command</h4>
<p>Here’s what happens if you pass a non-existent command:
</p>
<div class="smallexample">
<pre class="smallexample">-> -rubbish
<- ^error,msg="Undefined MI command: rubbish"
<- (gdb)
</pre></div>
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