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<a name="Global-Replacement"></a>
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<p>
Next: <a href="Init-and-Destroy-Functions.html#Init-and-Destroy-Functions" accesskey="n" rel="next">Init and Destroy Functions</a>, Previous: <a href="Extra-Reentrant-Argument.html#Extra-Reentrant-Argument" accesskey="p" rel="prev">Extra Reentrant Argument</a>, Up: <a href="Reentrant-Detail.html#Reentrant-Detail" accesskey="u" rel="up">Reentrant Detail</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Indices.html#Indices" title="Index" rel="index">Index</a>]</p>
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<a name="Global-Variables-Replaced-By-Macros"></a>
<h4 class="subsection">19.4.3 Global Variables Replaced By Macros</h4>

<a name="index-reentrant_002c-accessing-flex-variables"></a>
<p>All global variables in traditional flex have been replaced by macro equivalents.
</p>
<p>Note that in the above example, <code>yyout</code> and <code>yytext</code> are
not plain variables. These are macros that will expand to their equivalent lvalue.
All of the familiar <code>flex</code> globals have been replaced by their macro
equivalents. In particular, <code>yytext</code>, <code>yyleng</code>, <code>yylineno</code>,
<code>yyin</code>, <code>yyout</code>, <code>yyextra</code>, <code>yylval</code>, and <code>yylloc</code>
are macros. You may safely use these macros in actions as if they were plain
variables. We only tell you this so you don&rsquo;t expect to link to these variables
externally. Currently, each macro expands to a member of an internal struct, e.g.,
</p>
<div class="example">
<pre class="verbatim">#define yytext (((struct yyguts_t*)yyscanner)-&gt;yytext_r)
</pre></div>

<p>One important thing to remember about
<code>yytext</code>
and friends is that
<code>yytext</code>
is not a global variable in a reentrant
scanner, you can not access it directly from outside an action or from
other functions. You must use an accessor method, e.g.,
<code>yyget_text</code>,
to accomplish this. (See below).
</p>



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flex-doc 2.6.4-6 / usr / share / doc / flex-doc / html / Global-Replacement.html
