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<h3 class="section">27.6 Simple Examples of <span class="sc">gdb/mi</span> Interaction</h3>

<p><a name="index-g_t_0040sc_007bgdb_002fmi_007d_002c-simple-examples-2979"></a>
This subsection presents several simple examples of interaction using
the <span class="sc">gdb/mi</span> interface.  In these examples, &lsquo;<samp><span class="samp">-&gt;</span></samp>&rsquo; means that the
following line is passed to <span class="sc">gdb/mi</span> as input, while &lsquo;<samp><span class="samp">&lt;-</span></samp>&rsquo; means
the output received from <span class="sc">gdb/mi</span>.

   <p>Note the line breaks shown in the examples are here only for
readability, they don't appear in the real output.

<h4 class="subheading">Setting a Breakpoint</h4>

<p>Setting a breakpoint generates synchronous output which contains detailed
information of the breakpoint.

<pre class="smallexample">     -&gt; -break-insert main
     &lt;- ^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"}
     &lt;- (gdb)
</pre>
   <h4 class="subheading">Program Execution</h4>

<p>Program execution generates asynchronous records and MI gives the
reason that execution stopped.

<pre class="smallexample">     -&gt; -exec-run
     &lt;- ^running
     &lt;- (gdb)
     &lt;- *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"}
     &lt;- (gdb)
     -&gt; -exec-continue
     &lt;- ^running
     &lt;- (gdb)
     &lt;- *stopped,reason="exited-normally"
     &lt;- (gdb)
</pre>
   <h4 class="subheading">Quitting <span class="sc">gdb</span></h4>

<p>Quitting <span class="sc">gdb</span> just prints the result class &lsquo;<samp><span class="samp">^exit</span></samp>&rsquo;.

<pre class="smallexample">     -&gt; (gdb)
     &lt;- -gdb-exit
     &lt;- ^exit
</pre>
   <p>Please note that &lsquo;<samp><span class="samp">^exit</span></samp>&rsquo; is printed immediately, but it might
take some time for <span class="sc">gdb</span> to actually exit.  During that time, <span class="sc">gdb</span>
performs necessary cleanups, including killing programs being debugged
or disconnecting from debug hardware, so the frontend should wait till
<span class="sc">gdb</span> exits and should only forcibly kill <span class="sc">gdb</span> if it
fails to exit in reasonable time.

<h4 class="subheading">A Bad Command</h4>

<p>Here's what happens if you pass a non-existent command:

<pre class="smallexample">     -&gt; -rubbish
     &lt;- ^error,msg="Undefined MI command: rubbish"
     &lt;- (gdb)
</pre>
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