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<title>Fatal - replace functions with equivalents which succeed or die</title>
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<h1><a>Fatal - replace functions with equivalents which succeed or die</a></h1>
<p><a name="__index__"></a></p>
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<ul>
<li><a href="#name">NAME</a></li>
<li><a href="#synopsis">SYNOPSIS</a></li>
<li><a href="#description">DESCRIPTION</a></li>
<li><a href="#author">AUTHOR</a></li>
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<p>
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<h1><a name="name">NAME</a></h1>
<p>Fatal - replace functions with equivalents which succeed or die</p>
<p>
</p>
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<h1><a name="synopsis">SYNOPSIS</a></h1>
<pre>
<span class="keyword">use</span> <span class="variable">Fatal</span> <span class="string">qw(open close)</span><span class="operator">;</span>
</pre>
<pre>
<span class="keyword">sub</span><span class="variable"> juggle </span><span class="operator">{</span> <span class="operator">.</span> <span class="operator">.</span> <span class="operator">.</span> <span class="operator">}</span>
<span class="variable">import</span> <span class="variable">Fatal</span> <span class="string">'juggle'</span><span class="operator">;</span>
</pre>
<p>
</p>
<hr />
<h1><a name="description">DESCRIPTION</a></h1>
<p><code>Fatal</code> provides a way to conveniently replace functions which normally
return a false value when they fail with equivalents which raise exceptions
if they are not successful. This lets you use these functions without
having to test their return values explicitly on each call. Exceptions
can be caught using <a href="../lib/Pod/perlfunc.html#item_eval"><code>eval{}</code></a>. See <a href="../lib/Pod/perlfunc.html">the perlfunc manpage</a> and <a href="../lib/Pod/perlvar.html">the perlvar manpage</a> for details.</p>
<p>The do-or-die equivalents are set up simply by calling Fatal's
<a href="../lib/Pod/perlfunc.html#item_import"><code>import</code></a> routine, passing it the names of the functions to be
replaced. You may wrap both user-defined functions and overridable
CORE operators (except <a href="../lib/Pod/perlfunc.html#item_exec"><code>exec</code></a>, <a href="../lib/Pod/perlfunc.html#item_system"><code>system</code></a> which cannot be expressed
via prototypes) in this way.</p>
<p>If the symbol <code>:void</code> appears in the import list, then functions
named later in that import list raise an exception only when
these are called in void context--that is, when their return
values are ignored. For example</p>
<pre>
<span class="keyword">use</span> <span class="variable">Fatal</span> <span class="string">qw/:void open close/</span><span class="operator">;</span>
</pre>
<pre>
<span class="comment"># properly checked, so no exception raised on error</span>
<span class="keyword">if</span><span class="operator">(</span><span class="keyword">open</span><span class="operator">(</span><span class="variable">FH</span><span class="operator">,</span> <span class="string">"< /bogotic"</span><span class="operator">)</span> <span class="operator">{</span>
<span class="keyword">warn</span> <span class="string">"bogo file, dude: $!"</span><span class="operator">;</span>
<span class="operator">}</span>
</pre>
<pre>
<span class="comment"># not checked, so error raises an exception</span>
<span class="keyword">close</span> <span class="variable">FH</span><span class="operator">;</span>
</pre>
<p>
</p>
<hr />
<h1><a name="author">AUTHOR</a></h1>
<p><a href="mailto:Lionel.Cons@cern.ch">Lionel.Cons@cern.ch</a></p>
<p>prototype updates by Ilya Zakharevich <a href="mailto:ilya@math.ohio-state.edu">ilya@math.ohio-state.edu</a></p>
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