mingw/html/lib/Tie/Handle.html

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  13 <big><strong><span class="block">&nbsp;Tie::StdHandle  - base class definitions for tied handles</span></strong></big>
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  17 <p><a name="__index__"></a></p>
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  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="#more_information">MORE INFORMATION</a></li>
  26         <li><a href="#compatibility">COMPATIBILITY</a></li>
  27 </ul>
  28 <!-- INDEX END -->
  29
  30 <hr />
  31 <p>
  32 </p>
  33 <h1><a name="name">NAME</a></h1>
  34 <p>Tie::Handle, Tie::StdHandle  - base class definitions for tied handles</p>
  35 <p>
  36 </p>
  37 <hr />
  38 <h1><a name="synopsis">SYNOPSIS</a></h1>
  39 <pre>
  40     package NewHandle;
  41     require Tie::Handle;</pre>
  42 <pre>
  43     @ISA = qw(Tie::Handle);</pre>
  44 <pre>
  45     sub READ { ... }            # Provide a needed method
  46     sub TIEHANDLE { ... }       # Overrides inherited method</pre>
  47 <pre>
  48     package main;</pre>
  49 <pre>
  50     tie *FH, 'NewHandle';</pre>
  51 <p>
  52 </p>
  53 <hr />
  54 <h1><a name="description">DESCRIPTION</a></h1>
  55 <p>This module provides some skeletal methods for handle-tying classes. See
  56 <a href="file://C|\msysgit\mingw\html/pod/perltie.html">the perltie manpage</a> for a list of the functions required in tying a handle to a package.
  57 The basic <strong>Tie::Handle</strong> package provides a <code>new</code> method, as well as methods
  58 <code>TIEHANDLE</code>, <code>PRINT</code>, <code>PRINTF</code> and <code>GETC</code>.</p>
  59 <p>For developers wishing to write their own tied-handle classes, the methods
  60 are summarized below. The <a href="file://C|\msysgit\mingw\html/pod/perltie.html">the perltie manpage</a> section not only documents these, but
  61 has sample code as well:</p>
  62 <dl>
  63 <dt><strong><a name="item_tiehandle_classname_2c_list">TIEHANDLE classname, LIST</a></strong>
  64
  65 <dd>
  66 <p>The method invoked by the command <code>tie *glob, classname</code>. Associates a new
  67 glob instance with the specified class. <code>LIST</code> would represent additional
  68 arguments (along the lines of <a href="file://C|\msysgit\mingw\html/lib/AnyDBM_File.html">the AnyDBM_File manpage</a> and compatriots) needed to
  69 complete the association.</p>
  70 </dd>
  71 </li>
  72 <dt><strong><a name="item_write_this_2c_scalar_2c_length_2c_offset">WRITE this, scalar, length, offset</a></strong>
  73
  74 <dd>
  75 <p>Write <em>length</em> bytes of data from <em>scalar</em> starting at <em>offset</em>.</p>
  76 </dd>
  77 </li>
  78 <dt><strong><a name="item_print_this_2c_list">PRINT this, LIST</a></strong>
  79
  80 <dd>
  81 <p>Print the values in <em>LIST</em></p>
  82 </dd>
  83 </li>
  84 <dt><strong><a name="item_printf_this_2c_format_2c_list">PRINTF this, format, LIST</a></strong>
  85
  86 <dd>
  87 <p>Print the values in <em>LIST</em> using <em>format</em></p>
  88 </dd>
  89 </li>
  90 <dt><strong><a name="item_read_this_2c_scalar_2c_length_2c_offset">READ this, scalar, length, offset</a></strong>
  91
  92 <dd>
  93 <p>Read <em>length</em> bytes of data into <em>scalar</em> starting at <em>offset</em>.</p>
  94 </dd>
  95 </li>
  96 <dt><strong><a name="item_readline_this">READLINE this</a></strong>
  97
  98 <dd>
  99 <p>Read a single line</p>
 100 </dd>
 101 </li>
 102 <dt><strong><a name="item_getc_this">GETC this</a></strong>
 103
 104 <dd>
 105 <p>Get a single character</p>
 106 </dd>
 107 </li>
 108 <dt><strong><a name="item_close_this">CLOSE this</a></strong>
 109
 110 <dd>
 111 <p>Close the handle</p>
 112 </dd>
 113 </li>
 114 <dt><strong><a name="item_open_this_2c_filename">OPEN this, filename</a></strong>
 115
 116 <dd>
 117 <p>(Re-)open the handle</p>
 118 </dd>
 119 </li>
 120 <dt><strong><a name="item_binmode_this">BINMODE this</a></strong>
 121
 122 <dd>
 123 <p>Specify content is binary</p>
 124 </dd>
 125 </li>
 126 <dt><strong><a name="item_eof_this">EOF this</a></strong>
 127
 128 <dd>
 129 <p>Test for end of file.</p>
 130 </dd>
 131 </li>
 132 <dt><strong><a name="item_tell_this">TELL this</a></strong>
 133
 134 <dd>
 135 <p>Return position in the file.</p>
 136 </dd>
 137 </li>
 138 <dt><strong><a name="item_seek_this_2c_offset_2c_whence">SEEK this, offset, whence</a></strong>
 139
 140 <dd>
 141 <p>Position the file.</p>
 142 </dd>
 143 <dd>
 144 <p>Test for end of file.</p>
 145 </dd>
 146 </li>
 147 <dt><strong><a name="item_destroy_this">DESTROY this</a></strong>
 148
 149 <dd>
 150 <p>Free the storage associated with the tied handle referenced by <em>this</em>.
 151 This is rarely needed, as Perl manages its memory quite well. But the
 152 option exists, should a class wish to perform specific actions upon the
 153 destruction of an instance.</p>
 154 </dd>
 155 </li>
 156 </dl>
 157 <p>
 158 </p>
 159 <hr />
 160 <h1><a name="more_information">MORE INFORMATION</a></h1>
 161 <p>The <a href="file://C|\msysgit\mingw\html/pod/perltie.html">the perltie manpage</a> section contains an example of tying handles.</p>
 162 <p>
 163 </p>
 164 <hr />
 165 <h1><a name="compatibility">COMPATIBILITY</a></h1>
 166 <p>This version of Tie::Handle is neither related to nor compatible with
 167 the Tie::Handle (3.0) module available on CPAN. It was due to an
 168 accident that two modules with the same name appeared. The namespace
 169 clash has been cleared in favor of this module that comes with the
 170 perl core in September 2000 and accordingly the version number has
 171 been bumped up to 4.0.</p>
 172 <table border="0" width="100%" cellspacing="0" cellpadding="3">
 173 <tr><td class="block" style="background-color: #cccccc" valign="middle">
 174 <big><strong><span class="block">&nbsp;Tie::StdHandle  - base class definitions for tied handles</span></strong></big>
 175 </td></tr>
 176 </table>
 177
 178 </body>
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