ch20_03.htm

编程珍珠,里面很多好用的代码,大家可以参考学习呵呵,

a <tt class="literal">wait</tt> or an <tt class="literal">accept</tt>, or a <tt class="literal">read</tt> from your keyboard or a
socket) and haven't set up your own <tt class="literal">$SIG{INT}</tt> handler, then you
won't be able to Control-C your way back to the debugger, because the
debugger's own <tt class="literal">$SIG{INT}</tt> handler doesn't understand that it needs
to raise an exception to <em class="emphasis">longjmp</em>(3) out of slow syscalls.</p>
</dd>


<dt>
<b><tt class="literal">AutoTrace</tt></b>
</dt>
<dd>
<p>
<a name="INDEX-3607"></a>
Set the trace mode (similar to <tt class="literal">t</tt> command, but can be put into
<tt class="literal">PERLDB_OPTS</tt>).</p>
</dd>


<dt>
<b><tt class="literal">LineInfo</tt></b>
</dt>
<dd>
<p>
<a name="INDEX-3608"></a>
Assign the file or pipe to print line number info to.  If it is a pipe (say,
<tt class="literal">|visual_perl_db</tt>), then a short message is used.  This is the
mechanism used to interact with a slave editor or visual debugger,
such as the special <em class="emphasis">vi</em> or <em class="emphasis">emacs</em> hooks, or the <em class="emphasis">ddd</em> graphical
debugger.</p>
</dd>


<dt>
<b><tt class="literal">inhibit_exit</tt></b>
</dt>
<dd>
<p>If 0, allows stepping off the end of the program.
<a name="INDEX-3609"></a><a name="INDEX-3610"></a>
</p>
</dd>


<dt>
<b><tt class="literal">PrintRet</tt></b>
</dt>
<dd>
<p>
<a name="INDEX-3611"></a>
Print return value after <tt class="literal">r</tt> command if set (default).</p>
</dd>


<dt>
<b><tt class="literal">ornaments</tt></b>
</dt>
<dd>
<p>
<a name="INDEX-3612"></a><a name="INDEX-3613"></a><a name="INDEX-3614"></a>
Affects screen appearance of the command line (see the online docs for
<tt class="literal">Term::ReadLine</tt>).  There is currently no way to disable ornaments, which
can render some output illegible on some displays or with some
pagers.  This is considered a bug.</p>
</dd>


<dt>
<b><tt class="literal">frame</tt></b>
</dt>
<dd>
<p>
<a name="INDEX-3615"></a><a name="INDEX-3616"></a>
Affects printing of messages on entry and exit from subroutines.  If
<tt class="literal">frame &amp; 2</tt> is false, messages are printed on entry only.  (Printing
on exit might be useful if interspersed with other messages.)</p>

<p>If <tt class="literal">frame &amp; 4</tt>, arguments to functions are printed, plus context
and caller info.  If <tt class="literal">frame &amp; 8</tt>, overloaded <tt class="literal">stringify</tt> and
<tt class="literal">tie</tt>d <tt class="literal">FETCH</tt> are enabled on the printed arguments.
If <tt class="literal">frame &amp; 16</tt>, the return value from the subroutine is printed.</p>

<p>The length at which the argument list is truncated is governed by the
next option.</p>
</dd>


<dt>
<b><tt class="literal">maxTraceLen</tt></b>
</dt>
<dd>
<p>
<a name="INDEX-3617"></a><a name="INDEX-3618"></a>
Length to truncate the argument list when the <tt class="literal">frame</tt> option's
bit 4 is set.</p>
</dd>

</dl>

<p>The following options affect what happens with the <tt class="literal">V</tt>, <tt class="literal">X</tt>, and <tt class="literal">x</tt>
commands:</p>

<dl>
<dt>
<b><tt class="literal">arrayDepth</tt>, <tt class="literal">hashDepth</tt></b>
</dt>
<dd>
<p>
<a name="INDEX-3619"></a><a name="INDEX-3620"></a>
Print only the first <em class="emphasis">n</em> elements.  If <em class="emphasis">n</em> is omitted, all of the elements will be printed.</p>
</dd>


<dt>
<b><tt class="literal">compactDump</tt>, <tt class="literal">veryCompact</tt></b>
</dt>
<dd>
<p>
<a name="INDEX-3621"></a><a name="INDEX-3622"></a><a name="INDEX-3623"></a>
Change the style of array and hash output.  If <tt class="literal">compactDump</tt> is
enabled, short arrays may be printed on one line.</p>
</dd>


<dt>
<b><tt class="literal">globPrint</tt></b>
</dt>
<dd>
<p>
<a name="INDEX-3624"></a><a name="INDEX-3625"></a>
Print contents of typeglobs.</p>
</dd>


<dt>
<b><tt class="literal">DumpDBFiles</tt></b>
</dt>
<dd>
<p>Display arrays holding debugged files.</p>
</dd>


<dt>
<b><tt class="literal">DumpPackages</tt></b>
</dt>
<dd>
<p>Display symbol tables of packages.
<a name="INDEX-3626"></a><a name="INDEX-3627"></a>
</p>
</dd>


<dt>
<b><tt class="literal">DumpReused</tt></b>
</dt>
<dd>
<p>Display contents of "reused" addresses.
<a name="INDEX-3628"></a><a name="INDEX-3629"></a>
</p>
</dd>


<dt>
<b><tt class="literal">quote</tt>, <tt class="literal">HighBit</tt>, <tt class="literal">undefPrint</tt></b>
</dt>
<dd>
<p>
<a name="INDEX-3630"></a><a name="INDEX-3631"></a>
Change the style of string display.  The default value for <tt class="literal">quote</tt>
is <tt class="literal">auto</tt>; you can enable double-quotish or single-quotish format
by setting it to <tt class="literal">"</tt> or <tt class="literal">'</tt>, respectively.  By default, characters
with their high bit set are printed verbatim.</p>
</dd>


<dt>
<b><tt class="literal">UsageOnly</tt></b>
</dt>
<dd>
<p>
<a name="INDEX-3632"></a>
Instead of showing the contents of a package's variables, with this
option enabled, you get a rudimentary per-package memory usage dump
based on the total size of the strings found in package variables. Because the package symbol table is used, lexical variables are
ignored.</p>
</dd>

</dl>





<a name="INDEX-3633"></a><a name="INDEX-3634"></a><a name="INDEX-3635"></a><a name="INDEX-3636"></a>


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