mingw/html/lib/B/Showlex.html

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  13 <big><strong><span class="block">&nbsp;B::Showlex - Show lexical variables used in functions or files</span></strong></big>
  14 </td></tr>
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  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         <li><a href="#examples">EXAMPLES</a></li>
  26         <ul>
  27
  28                 <li><a href="#options">OPTIONS</a></li>
  29         </ul>
  30
  31         <li><a href="#see_also">SEE ALSO</a></li>
  32         <li><a href="#todo">TODO</a></li>
  33         <li><a href="#author">AUTHOR</a></li>
  34 </ul>
  35 <!-- INDEX END -->
  36
  37 <hr />
  38 <p>
  39 </p>
  40 <h1><a name="name">NAME</a></h1>
  41 <p>B::Showlex - Show lexical variables used in functions or files</p>
  42 <p>
  43 </p>
  44 <hr />
  45 <h1><a name="synopsis">SYNOPSIS</a></h1>
  46 <pre>
  47         perl -MO=Showlex[,-OPTIONS][,SUBROUTINE] foo.pl</pre>
  48 <p>
  49 </p>
  50 <hr />
  51 <h1><a name="description">DESCRIPTION</a></h1>
  52 <p>When a comma-separated list of subroutine names is given as options, Showlex
  53 prints the lexical variables used in those subroutines.  Otherwise, it prints
  54 the file-scope lexicals in the file.</p>
  55 <p>
  56 </p>
  57 <hr />
  58 <h1><a name="examples">EXAMPLES</a></h1>
  59 <p>Traditional form:</p>
  60 <pre>
  61  $ perl -MO=Showlex -e 'my ($i,$j,$k)=(1,&quot;foo&quot;)'
  62  Pad of lexical names for comppadlist has 4 entries
  63  0: SPECIAL #1 &amp;PL_sv_undef
  64  1: PVNV (0x9db0fb0) $i
  65  2: PVNV (0x9db0f38) $j
  66  3: PVNV (0x9db0f50) $k
  67  Pad of lexical values for comppadlist has 5 entries
  68  0: SPECIAL #1 &amp;PL_sv_undef
  69  1: NULL (0x9da4234)
  70  2: NULL (0x9db0f2c)
  71  3: NULL (0x9db0f44)
  72  4: NULL (0x9da4264)
  73  -e syntax OK</pre>
  74 <p>New-style form:</p>
  75 <pre>
  76  $ perl -MO=Showlex,-newlex -e 'my ($i,$j,$k)=(1,&quot;foo&quot;)'
  77  main Pad has 4 entries
  78  0: SPECIAL #1 &amp;PL_sv_undef
  79  1: PVNV (0xa0c4fb8) &quot;$i&quot; = NULL (0xa0b8234)
  80  2: PVNV (0xa0c4f40) &quot;$j&quot; = NULL (0xa0c4f34)
  81  3: PVNV (0xa0c4f58) &quot;$k&quot; = NULL (0xa0c4f4c)
  82  -e syntax OK</pre>
  83 <p>New form, no specials, outside O framework:</p>
  84 <pre>
  85  $ perl -MB::Showlex -e \
  86     'my ($i,$j,$k)=(1,&quot;foo&quot;); B::Showlex::compile(-newlex,-nosp)-&gt;()'
  87  main Pad has 4 entries
  88  1: PVNV (0x998ffb0) &quot;$i&quot; = IV (0x9983234) 1
  89  2: PVNV (0x998ff68) &quot;$j&quot; = PV (0x998ff5c) &quot;foo&quot;
  90  3: PVNV (0x998ff80) &quot;$k&quot; = NULL (0x998ff74)</pre>
  91 <p>Note that this example shows the values of the lexicals, whereas the other
  92 examples did not (as they're compile-time only).</p>
  93 <p>
  94 </p>
  95 <h2><a name="options">OPTIONS</a></h2>
  96 <p>The <code>-newlex</code> option produces a more readable <code>name =&gt; value</code> format,
  97 and is shown in the second example above.</p>
  98 <p>The <code>-nosp</code> option eliminates reporting of SPECIALs, such as <code>0: SPECIAL
  99 #1 &amp;PL_sv_undef</code> above.  Reporting of SPECIALs can sometimes overwhelm
 100 your declared lexicals.</p>
 101 <p>
 102 </p>
 103 <hr />
 104 <h1><a name="see_also">SEE ALSO</a></h1>
 105 <p><code>B::Showlex</code> can also be used outside of the O framework, as in the third
 106 example.  See <code>B::Concise</code> for a fuller explanation of reasons.</p>
 107 <p>
 108 </p>
 109 <hr />
 110 <h1><a name="todo">TODO</a></h1>
 111 <p>Some of the reported info, such as hex addresses, is not particularly
 112 valuable.  Other information would be more useful for the typical
 113 programmer, such as line-numbers, pad-slot reuses, etc..  Given this,
 114 -newlex isnt a particularly good flag-name.</p>
 115 <p>
 116 </p>
 117 <hr />
 118 <h1><a name="author">AUTHOR</a></h1>
 119 <p>Malcolm Beattie, <code>mbeattie@sable.ox.ac.uk</code></p>
 120 <table border="0" width="100%" cellspacing="0" cellpadding="3">
 121 <tr><td class="block" style="background-color: #cccccc" valign="middle">
 122 <big><strong><span class="block">&nbsp;B::Showlex - Show lexical variables used in functions or files</span></strong></big>
 123 </td></tr>
 124 </table>
 125
 126 </body>
 127
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