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<a name="Accessor-Methods"></a>
<div class="header">
<p>
Next: <a href="Extra-Data.html#Extra-Data" accesskey="n" rel="next">Extra Data</a>, Previous: <a href="Init-and-Destroy-Functions.html#Init-and-Destroy-Functions" accesskey="p" rel="prev">Init and Destroy Functions</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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<hr>
<a name="Accessing-Variables-with-Reentrant-Scanners"></a>
<h4 class="subsection">19.4.5 Accessing Variables with Reentrant Scanners</h4>

<a name="index-reentrant_002c-accessor-functions"></a>
<p>Accessor methods (get/set functions) provide access to common
<code>flex</code> variables.
</p>
<p>Many scanners that you build will be part of a larger project. Portions
of your project will need access to <code>flex</code> values, such as
<code>yytext</code>.  In a non-reentrant scanner, these values are global, so
there is no problem accessing them. However, in a reentrant scanner, there are no
global <code>flex</code> values. You can not access them directly.  Instead,
you must access <code>flex</code> values using accessor methods (get/set
functions). Each accessor method is named <code>yyget_NAME</code> or
<code>yyset_NAME</code>, where <code>NAME</code> is the name of the <code>flex</code>
variable you want. For example:
</p>
<a name="index-accessor-functions_002c-use-of"></a>
<div class="example">
<pre class="verbatim">    /* Set the last character of yytext to NULL. */
    void chop ( yyscan_t scanner )
    {
        int len = yyget_leng( scanner );
        yyget_text( scanner )[len - 1] = '\0';
    }
</pre></div>

<p>The above code may be called from within an action like this:
</p>
<div class="example">
<pre class="verbatim">    %%
    .+\n    { chop( yyscanner );}
</pre></div>

<p>You may find that <code>%option header-file</code> is particularly useful for generating
prototypes of all the accessor functions. See <a href="Options-for-Specifying-Filenames.html#option_002dheader">option-header</a>.
</p>



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flex-doc 2.6.4-6 / usr / share / doc / flex-doc / html / Accessor-Methods.html
