mingw/html/ext/Devel/Peek/Peek.html

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  13 <big><strong><span class="block">&nbsp;Devel::Peek - A data debugging tool for the XS programmer</span></strong></big>
  14 </td></tr>
  15 </table>
  16
  17 <p><a name="__index__"></a></p>
  18 <!-- INDEX BEGIN -->
  19
  20 <ul>
  21
  22         <li><a href="#name">NAME</a></li>
  23         <li><a href="#synopsis">SYNOPSIS</a></li>
  24         <li><a href="#description">DESCRIPTION</a></li>
  25         <ul>
  26
  27                 <li><a href="#runtime_debugging">Runtime debugging</a></li>
  28                 <li><a href="#memory_footprint_debugging">Memory footprint debugging</a></li>
  29         </ul>
  30
  31         <li><a href="#examples">EXAMPLES</a></li>
  32         <ul>
  33
  34                 <li><a href="#a_simple_scalar_string">A simple scalar string</a></li>
  35                 <li><a href="#a_simple_scalar_number">A simple scalar number</a></li>
  36                 <li><a href="#a_simple_scalar_with_an_extra_reference">A simple scalar with an extra reference</a></li>
  37                 <li><a href="#a_reference_to_a_simple_scalar">A reference to a simple scalar</a></li>
  38                 <li><a href="#a_reference_to_an_array">A reference to an array</a></li>
  39                 <li><a href="#a_reference_to_a_hash">A reference to a hash</a></li>
  40                 <li><a href="#dumping_a_large_array_or_hash">Dumping a large array or hash</a></li>
  41                 <li><a href="#a_reference_to_an_sv_which_holds_a_c_pointer">A reference to an SV which holds a C pointer</a></li>
  42                 <li><a href="#a_reference_to_a_subroutine">A reference to a subroutine</a></li>
  43         </ul>
  44
  45         <li><a href="#exports">EXPORTS</a></li>
  46         <li><a href="#bugs">BUGS</a></li>
  47         <li><a href="#author">AUTHOR</a></li>
  48         <li><a href="#see_also">SEE ALSO</a></li>
  49 </ul>
  50 <!-- INDEX END -->
  51
  52 <hr />
  53 <p>
  54 </p>
  55 <h1><a name="name">NAME</a></h1>
  56 <p>Devel::Peek - A data debugging tool for the XS programmer</p>
  57 <p>
  58 </p>
  59 <hr />
  60 <h1><a name="synopsis">SYNOPSIS</a></h1>
  61 <pre>
  62         use Devel::Peek;
  63         Dump( $a );
  64         Dump( $a, 5 );
  65         DumpArray( 5, $a, $b, ... );
  66         mstat &quot;Point 5&quot;;</pre>
  67 <pre>
  68         use Devel::Peek ':opd=st';</pre>
  69 <p>
  70 </p>
  71 <hr />
  72 <h1><a name="description">DESCRIPTION</a></h1>
  73 <p>Devel::Peek contains functions which allows raw Perl datatypes to be
  74 manipulated from a Perl script.  This is used by those who do XS programming
  75 to check that the data they are sending from C to Perl looks as they think
  76 it should look.  The trick, then, is to know what the raw datatype is
  77 supposed to look like when it gets to Perl.  This document offers some tips
  78 and hints to describe good and bad raw data.</p>
  79 <p>It is very possible that this document will fall far short of being useful
  80 to the casual reader.  The reader is expected to understand the material in
  81 the first few sections of <a href="file://C|\msysgit\mingw\html/pod/perlguts.html">the perlguts manpage</a>.</p>
  82 <p>Devel::Peek supplies a <code>Dump()</code> function which can dump a raw Perl
  83 datatype, and <code>mstat(&quot;marker&quot;)</code> function to report on memory usage
  84 (if perl is compiled with corresponding option).  The function
  85 <code>DeadCode()</code> provides statistics on the data ``frozen'' into inactive
  86 <code>CV</code>.  Devel::Peek also supplies <code>SvREFCNT()</code>, <code>SvREFCNT_inc()</code>, and
  87 <code>SvREFCNT_dec()</code> which can query, increment, and decrement reference
  88 counts on SVs.  This document will take a passive, and safe, approach
  89 to data debugging and for that it will describe only the <code>Dump()</code>
  90 function.</p>
  91 <p>Function <code>DumpArray()</code> allows dumping of multiple values (useful when you
  92 need to analyze returns of functions).</p>
  93 <p>The global variable $Devel::Peek::pv_limit can be set to limit the
  94 number of character printed in various string values.  Setting it to 0
  95 means no limit.</p>
  96 <p>If <code>use Devel::Peek</code> directive has a <code>:opd=FLAGS</code> argument,
  97 this switches on debugging of opcode dispatch.  <code>FLAGS</code> should be a
  98 combination of <a href="file://C|\msysgit\mingw\html/pod/perlguts.html#item_s"><code>s</code></a>, <code>t</code>, and <code>P</code> (see <strong>-D</strong> flags in <a href="file://C|\msysgit\mingw\html/pod/perlrun.html">the perlrun manpage</a>).
  99 <code>:opd</code> is a shortcut for <code>:opd=st</code>.</p>
 100 <p>
 101 </p>
 102 <h2><a name="runtime_debugging">Runtime debugging</a></h2>
 103 <p><code>CvGV($cv)</code> return one of the globs associated to a subroutine reference $cv.</p>
 104 <p><code>debug_flags()</code> returns a string representation of <a href="file://C|\msysgit\mingw\html/pod/perlvar.html#item___d"><code>$^D</code></a> (similar to
 105 what is allowed for <strong>-D</strong> flag).  When called with a numeric argument,
 106 sets $^D to the corresponding value.  When called with an argument of
 107 the form <code>&quot;flags-flags&quot;</code>, set on/off bits of <a href="file://C|\msysgit\mingw\html/pod/perlvar.html#item___d"><code>$^D</code></a> corresponding to
 108 letters before/after <code>-</code>.  (The returned value is for <a href="file://C|\msysgit\mingw\html/pod/perlvar.html#item___d"><code>$^D</code></a> before
 109 the modification.)</p>
 110 <p><code>runops_debug()</code> returns true if the current <em>opcode dispatcher</em> is the
 111 debugging one.  When called with an argument, switches to debugging or
 112 non-debugging dispatcher depending on the argument (active for
 113 newly-entered subs/etc only).  (The returned value is for the dispatcher before the modification.)</p>
 114 <p>
 115 </p>
 116 <h2><a name="memory_footprint_debugging">Memory footprint debugging</a></h2>
 117 <p>When perl is compiled with support for memory footprint debugging
 118 (default with Perl's malloc()), Devel::Peek provides an access to this API.</p>
 119 <p>Use <code>mstat()</code> function to emit a memory state statistic to the terminal.
 120 For more information on the format of output of <code>mstat()</code> see
 121 <a href="file://C|\msysgit\mingw\html/pod/perldebguts.html#using_c__env_perl_debug_mstats__">Using <code>$ENV{PERL_DEBUG_MSTATS}</code> in the perldebguts manpage</a>.</p>
 122 <p>Three additional functions allow access to this statistic from Perl.
 123 First, use <code>mstats_fillhash(%hash)</code> to get the information contained
 124 in the output of <code>mstat()</code> into %hash. The field of this hash are</p>
 125 <pre>
 126   minbucket nbuckets sbrk_good sbrk_slack sbrked_remains sbrks start_slack
 127   topbucket topbucket_ev topbucket_odd total total_chain total_sbrk totfree</pre>
 128 <p>Two additional fields <code>free</code>, <code>used</code> contain array references which
 129 provide per-bucket count of free and used chunks.  Two other fields
 130 <code>mem_size</code>, <code>available_size</code> contain array references which provide
 131 the information about the allocated size and usable size of chunks in
 132 each bucket.  Again, see <a href="file://C|\msysgit\mingw\html/pod/perldebguts.html#using_c__env_perl_debug_mstats__">Using <code>$ENV{PERL_DEBUG_MSTATS}</code> in the perldebguts manpage</a>
 133 for details.</p>
 134 <p>Keep in mind that only the first several ``odd-numbered'' buckets are
 135 used, so the information on size of the ``odd-numbered'' buckets which are
 136 not used is probably meaningless.</p>
 137 <p>The information in</p>
 138 <pre>
 139  mem_size available_size minbucket nbuckets</pre>
 140 <p>is the property of a particular build of perl, and does not depend on
 141 the current process.  If you do not provide the optional argument to
 142 the functions mstats_fillhash(), fill_mstats(), mstats2hash(), then
 143 the information in fields <code>mem_size</code>, <code>available_size</code> is not
 144 updated.</p>
 145 <p><code>fill_mstats($buf)</code> is a much cheaper call (both speedwise and
 146 memory-wise) which collects the statistic into $buf in
 147 machine-readable form.  At a later moment you may need to call
 148 <code>mstats2hash($buf, %hash)</code> to use this information to fill %hash.</p>
 149 <p>All three APIs <code>fill_mstats($buf)</code>, <code>mstats_fillhash(%hash)</code>, and
 150 <code>mstats2hash($buf, %hash)</code> are designed to allocate no memory if used
 151 <em>the second time</em> on the same $buf and/or %hash.</p>
 152 <p>So, if you want to collect memory info in a cycle, you may call</p>
 153 <pre>
 154   $#buf = 999;
 155   fill_mstats($_) for @buf;
 156   mstats_fillhash(%report, 1);          # Static info too</pre>
 157 <pre>
 158   foreach (@buf) {
 159     # Do something...
 160     fill_mstats $_;                     # Collect statistic
 161   }
 162   foreach (@buf) {
 163     mstats2hash($_, %report);           # Preserve static info
 164     # Do something with %report
 165   }</pre>
 166 <p>
 167 </p>
 168 <hr />
 169 <h1><a name="examples">EXAMPLES</a></h1>
 170 <p>The following examples don't attempt to show everything as that would be a
 171 monumental task, and, frankly, we don't want this manpage to be an internals
 172 document for Perl.  The examples do demonstrate some basics of the raw Perl
 173 datatypes, and should suffice to get most determined people on their way.
 174 There are no guidewires or safety nets, nor blazed trails, so be prepared to
 175 travel alone from this point and on and, if at all possible, don't fall into
 176 the quicksand (it's bad for business).</p>
 177 <p>Oh, one final bit of advice: take <a href="file://C|\msysgit\mingw\html/pod/perlguts.html">the perlguts manpage</a> with you.  When you return we
 178 expect to see it well-thumbed.</p>
 179 <p>
 180 </p>
 181 <h2><a name="a_simple_scalar_string">A simple scalar string</a></h2>
 182 <p>Let's begin by looking a simple scalar which is holding a string.</p>
 183 <pre>
 184         use Devel::Peek;
 185         $a = &quot;hello&quot;;
 186         Dump $a;</pre>
 187 <p>The output:</p>
 188 <pre>
 189         SV = PVIV(0xbc288)
 190           REFCNT = 1
 191           FLAGS = (POK,pPOK)
 192           IV = 0
 193           PV = 0xb2048 &quot;hello&quot;\0
 194           CUR = 5
 195           LEN = 6</pre>
 196 <p>This says <a href="file://C|\msysgit\mingw\html/pod/perlvar.html#item__a"><code>$a</code></a> is an SV, a scalar.  The scalar is a PVIV, a string.
 197 Its reference count is 1.  It has the <code>POK</code> flag set, meaning its
 198 current PV field is valid.  Because POK is set we look at the PV item
 199 to see what is in the scalar.  The \0 at the end indicate that this
 200 PV is properly NUL-terminated.
 201 If the FLAGS had been IOK we would look
 202 at the IV item.  CUR indicates the number of characters in the PV.
 203 LEN indicates the number of bytes requested for the PV (one more than
 204 CUR, in this case, because LEN includes an extra byte for the
 205 end-of-string marker).</p>
 206 <p>
 207 </p>
 208 <h2><a name="a_simple_scalar_number">A simple scalar number</a></h2>
 209 <p>If the scalar contains a number the raw SV will be leaner.</p>
 210 <pre>
 211         use Devel::Peek;
 212         $a = 42;
 213         Dump $a;</pre>
 214 <p>The output:</p>
 215 <pre>
 216         SV = IV(0xbc818)
 217           REFCNT = 1
 218           FLAGS = (IOK,pIOK)
 219           IV = 42</pre>
 220 <p>This says <a href="file://C|\msysgit\mingw\html/pod/perlvar.html#item__a"><code>$a</code></a> is an SV, a scalar.  The scalar is an IV, a number.  Its
 221 reference count is 1.  It has the <code>IOK</code> flag set, meaning it is currently
 222 being evaluated as a number.  Because IOK is set we look at the IV item to
 223 see what is in the scalar.</p>
 224 <p>
 225 </p>
 226 <h2><a name="a_simple_scalar_with_an_extra_reference">A simple scalar with an extra reference</a></h2>
 227 <p>If the scalar from the previous example had an extra reference:</p>
 228 <pre>
 229         use Devel::Peek;
 230         $a = 42;
 231         $b = \$a;
 232         Dump $a;</pre>
 233 <p>The output:</p>
 234 <pre>
 235         SV = IV(0xbe860)
 236           REFCNT = 2
 237           FLAGS = (IOK,pIOK)
 238           IV = 42</pre>
 239 <p>Notice that this example differs from the previous example only in its
 240 reference count.  Compare this to the next example, where we dump <a href="file://C|\msysgit\mingw\html/pod/perlvar.html#item__b"><code>$b</code></a>
 241 instead of <a href="file://C|\msysgit\mingw\html/pod/perlvar.html#item__a"><code>$a</code></a>.</p>
 242 <p>
 243 </p>
 244 <h2><a name="a_reference_to_a_simple_scalar">A reference to a simple scalar</a></h2>
 245 <p>This shows what a reference looks like when it references a simple scalar.</p>
 246 <pre>
 247         use Devel::Peek;
 248         $a = 42;
 249         $b = \$a;
 250         Dump $b;</pre>
 251 <p>The output:</p>
 252 <pre>
 253         SV = RV(0xf041c)
 254           REFCNT = 1
 255           FLAGS = (ROK)
 256           RV = 0xbab08
 257         SV = IV(0xbe860)
 258           REFCNT = 2
 259           FLAGS = (IOK,pIOK)
 260           IV = 42</pre>
 261 <p>Starting from the top, this says <a href="file://C|\msysgit\mingw\html/pod/perlvar.html#item__b"><code>$b</code></a> is an SV.  The scalar is an RV, a
 262 reference.  It has the <code>ROK</code> flag set, meaning it is a reference.  Because
 263 ROK is set we have an RV item rather than an IV or PV.  Notice that Dump
 264 follows the reference and shows us what <a href="file://C|\msysgit\mingw\html/pod/perlvar.html#item__b"><code>$b</code></a> was referencing.  We see the
 265 same <a href="file://C|\msysgit\mingw\html/pod/perlvar.html#item__a"><code>$a</code></a> that we found in the previous example.</p>
 266 <p>Note that the value of <code>RV</code> coincides with the numbers we see when we
 267 stringify $b. The addresses inside <code>RV()</code> and <code>IV()</code> are addresses of
 268 <code>X***</code> structure which holds the current state of an <code>SV</code>. This
 269 address may change during lifetime of an SV.</p>
 270 <p>
 271 </p>
 272 <h2><a name="a_reference_to_an_array">A reference to an array</a></h2>
 273 <p>This shows what a reference to an array looks like.</p>
 274 <pre>
 275         use Devel::Peek;
 276         $a = [42];
 277         Dump $a;</pre>
 278 <p>The output:</p>
 279 <pre>
 280         SV = RV(0xf041c)
 281           REFCNT = 1
 282           FLAGS = (ROK)
 283           RV = 0xb2850
 284         SV = PVAV(0xbd448)
 285           REFCNT = 1
 286           FLAGS = ()
 287           IV = 0
 288           NV = 0
 289           ARRAY = 0xb2048
 290           ALLOC = 0xb2048
 291           FILL = 0
 292           MAX = 0
 293           ARYLEN = 0x0
 294           FLAGS = (REAL)
 295         Elt No. 0 0xb5658
 296         SV = IV(0xbe860)
 297           REFCNT = 1
 298           FLAGS = (IOK,pIOK)
 299           IV = 42</pre>
 300 <p>This says <a href="file://C|\msysgit\mingw\html/pod/perlvar.html#item__a"><code>$a</code></a> is an SV and that it is an RV.  That RV points to
 301 another SV which is a PVAV, an array.  The array has one element,
 302 element zero, which is another SV. The field <code>FILL</code> above indicates
 303 the last element in the array, similar to <code>$#$a</code>.</p>
 304 <p>If <a href="file://C|\msysgit\mingw\html/pod/perlvar.html#item__a"><code>$a</code></a> pointed to an array of two elements then we would see the
 305 following.</p>
 306 <pre>
 307         use Devel::Peek 'Dump';
 308         $a = [42,24];
 309         Dump $a;</pre>
 310 <p>The output:</p>
 311 <pre>
 312         SV = RV(0xf041c)
 313           REFCNT = 1
 314           FLAGS = (ROK)
 315           RV = 0xb2850
 316         SV = PVAV(0xbd448)
 317           REFCNT = 1
 318           FLAGS = ()
 319           IV = 0
 320           NV = 0
 321           ARRAY = 0xb2048
 322           ALLOC = 0xb2048
 323           FILL = 0
 324           MAX = 0
 325           ARYLEN = 0x0
 326           FLAGS = (REAL)
 327         Elt No. 0  0xb5658
 328         SV = IV(0xbe860)
 329           REFCNT = 1
 330           FLAGS = (IOK,pIOK)
 331           IV = 42
 332         Elt No. 1  0xb5680
 333         SV = IV(0xbe818)
 334           REFCNT = 1
 335           FLAGS = (IOK,pIOK)
 336           IV = 24</pre>
 337 <p>Note that <code>Dump</code> will not report <em>all</em> the elements in the array,
 338 only several first (depending on how deep it already went into the
 339 report tree).</p>
 340 <p>
 341 </p>
 342 <h2><a name="a_reference_to_a_hash">A reference to a hash</a></h2>
 343 <p>The following shows the raw form of a reference to a hash.</p>
 344 <pre>
 345         use Devel::Peek;
 346         $a = {hello=&gt;42};
 347         Dump $a;</pre>
 348 <p>The output:</p>
 349 <pre>
 350         SV = RV(0x8177858) at 0x816a618
 351           REFCNT = 1
 352           FLAGS = (ROK)
 353           RV = 0x814fc10
 354           SV = PVHV(0x8167768) at 0x814fc10
 355             REFCNT = 1
 356             FLAGS = (SHAREKEYS)
 357             IV = 1
 358             NV = 0
 359             ARRAY = 0x816c5b8  (0:7, 1:1)
 360             hash quality = 100.0%
 361             KEYS = 1
 362             FILL = 1
 363             MAX = 7
 364             RITER = -1
 365             EITER = 0x0
 366             Elt &quot;hello&quot; HASH = 0xc8fd181b
 367             SV = IV(0x816c030) at 0x814fcf4
 368               REFCNT = 1
 369               FLAGS = (IOK,pIOK)
 370               IV = 42</pre>
 371 <p>This shows <a href="file://C|\msysgit\mingw\html/pod/perlvar.html#item__a"><code>$a</code></a> is a reference pointing to an SV.  That SV is a PVHV, a
 372 hash. Fields RITER and EITER are used by <code>each</code>.</p>
 373 <p>The ``quality'' of a hash is defined as the total number of comparisons needed
 374 to access every element once, relative to the expected number needed for a
 375 random hash. The value can go over 100%.</p>
 376 <p>The total number of comparisons is equal to the sum of the squares of the
 377 number of entries in each bucket.  For a random hash of <code>&lt;n</code>&gt; keys into
 378 <code>&lt;k</code>&gt; buckets, the expected value is:</p>
 379 <pre>
 380                 n + n(n-1)/2k</pre>
 381 <p>
 382 </p>
 383 <h2><a name="dumping_a_large_array_or_hash">Dumping a large array or hash</a></h2>
 384 <p>The <code>Dump()</code> function, by default, dumps up to 4 elements from a
 385 toplevel array or hash.  This number can be increased by supplying a
 386 second argument to the function.</p>
 387 <pre>
 388         use Devel::Peek;
 389         $a = [10,11,12,13,14];
 390         Dump $a;</pre>
 391 <p>Notice that <code>Dump()</code> prints only elements 10 through 13 in the above code.
 392 The following code will print all of the elements.</p>
 393 <pre>
 394         use Devel::Peek 'Dump';
 395         $a = [10,11,12,13,14];
 396         Dump $a, 5;</pre>
 397 <p>
 398 </p>
 399 <h2><a name="a_reference_to_an_sv_which_holds_a_c_pointer">A reference to an SV which holds a C pointer</a></h2>
 400 <p>This is what you really need to know as an XS programmer, of course.  When
 401 an XSUB returns a pointer to a C structure that pointer is stored in an SV
 402 and a reference to that SV is placed on the XSUB stack.  So the output from
 403 an XSUB which uses something like the T_PTROBJ map might look something like
 404 this:</p>
 405 <pre>
 406         SV = RV(0xf381c)
 407           REFCNT = 1
 408           FLAGS = (ROK)
 409           RV = 0xb8ad8
 410         SV = PVMG(0xbb3c8)
 411           REFCNT = 1
 412           FLAGS = (OBJECT,IOK,pIOK)
 413           IV = 729160
 414           NV = 0
 415           PV = 0
 416           STASH = 0xc1d10       &quot;CookBookB::Opaque&quot;</pre>
 417 <p>This shows that we have an SV which is an RV.  That RV points at another
 418 SV.  In this case that second SV is a PVMG, a blessed scalar.  Because it is
 419 blessed it has the <code>OBJECT</code> flag set.  Note that an SV which holds a C
 420 pointer also has the <code>IOK</code> flag set.  The <code>STASH</code> is set to the package
 421 name which this SV was blessed into.</p>
 422 <p>The output from an XSUB which uses something like the T_PTRREF map, which
 423 doesn't bless the object, might look something like this:</p>
 424 <pre>
 425         SV = RV(0xf381c)
 426           REFCNT = 1
 427           FLAGS = (ROK)
 428           RV = 0xb8ad8
 429         SV = PVMG(0xbb3c8)
 430           REFCNT = 1
 431           FLAGS = (IOK,pIOK)
 432           IV = 729160
 433           NV = 0
 434           PV = 0</pre>
 435 <p>
 436 </p>
 437 <h2><a name="a_reference_to_a_subroutine">A reference to a subroutine</a></h2>
 438 <p>Looks like this:</p>
 439 <pre>
 440         SV = RV(0x798ec)
 441           REFCNT = 1
 442           FLAGS = (TEMP,ROK)
 443           RV = 0x1d453c
 444         SV = PVCV(0x1c768c)
 445           REFCNT = 2
 446           FLAGS = ()
 447           IV = 0
 448           NV = 0
 449           COMP_STASH = 0x31068  &quot;main&quot;
 450           START = 0xb20e0
 451           ROOT = 0xbece0
 452           XSUB = 0x0
 453           XSUBANY = 0
 454           GVGV::GV = 0x1d44e8   &quot;MY&quot; :: &quot;top_targets&quot;
 455           FILE = &quot;(eval 5)&quot;
 456           DEPTH = 0
 457           PADLIST = 0x1c9338</pre>
 458 <p>This shows that</p>
 459 <ul>
 460 <li>
 461 <p>the subroutine is not an XSUB (since <code>START</code> and <code>ROOT</code> are
 462 non-zero, and <code>XSUB</code> is zero);</p>
 463 </li>
 464 <li>
 465 <p>that it was compiled in the package <code>main</code>;</p>
 466 </li>
 467 <li>
 468 <p>under the name <code>MY::top_targets</code>;</p>
 469 </li>
 470 <li>
 471 <p>inside a 5th eval in the program;</p>
 472 </li>
 473 <li>
 474 <p>it is not currently executed (see <code>DEPTH</code>);</p>
 475 </li>
 476 <li>
 477 <p>it has no prototype (<code>PROTOTYPE</code> field is missing).</p>
 478 </li>
 479 </ul>
 480 <p>
 481 </p>
 482 <hr />
 483 <h1><a name="exports">EXPORTS</a></h1>
 484 <p><code>Dump</code>, <code>mstat</code>, <code>DeadCode</code>, <code>DumpArray</code>, <code>DumpWithOP</code> and
 485 <code>DumpProg</code>, <code>fill_mstats</code>, <code>mstats_fillhash</code>, <code>mstats2hash</code> by
 486 default. Additionally available <code>SvREFCNT</code>, <code>SvREFCNT_inc</code> and
 487 <code>SvREFCNT_dec</code>.</p>
 488 <p>
 489 </p>
 490 <hr />
 491 <h1><a name="bugs">BUGS</a></h1>
 492 <p>Readers have been known to skip important parts of <a href="file://C|\msysgit\mingw\html/pod/perlguts.html">the perlguts manpage</a>, causing much
 493 frustration for all.</p>
 494 <p>
 495 </p>
 496 <hr />
 497 <h1><a name="author">AUTHOR</a></h1>
 498 <p>Ilya Zakharevich     <a href="mailto:ilya@math.ohio-state.edu">ilya@math.ohio-state.edu</a></p>
 499 <p>Copyright (c) 1995-98 Ilya Zakharevich. All rights reserved.
 500 This program is free software; you can redistribute it and/or
 501 modify it under the same terms as Perl itself.</p>
 502 <p>Author of this software makes no claim whatsoever about suitability,
 503 reliability, edability, editability or usability of this product, and
 504 should not be kept liable for any damage resulting from the use of
 505 it. If you can use it, you are in luck, if not, I should not be kept
 506 responsible. Keep a handy copy of your backup tape at hand.</p>
 507 <p>
 508 </p>
 509 <hr />
 510 <h1><a name="see_also">SEE ALSO</a></h1>
 511 <p><a href="file://C|\msysgit\mingw\html/pod/perlguts.html">the perlguts manpage</a>, and <a href="file://C|\msysgit\mingw\html/pod/perlguts.html">the perlguts manpage</a>, again.</p>
 512 <table border="0" width="100%" cellspacing="0" cellpadding="3">
 513 <tr><td class="block" style="background-color: #cccccc" valign="middle">
 514 <big><strong><span class="block">&nbsp;Devel::Peek - A data debugging tool for the XS programmer</span></strong></big>
 515 </td></tr>
 516 </table>
 517
 518 </body>
 519
 520 </html>