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<a name="GFORTRAN_005fUNBUFFERED_005fPRECONNECTED_002d_002d_002dDo-not-buffer-I_002fO-on-preconnected-units"></a>
<h3 class="section">3.6 <code>GFORTRAN_UNBUFFERED_PRECONNECTED</code>&mdash;Do not buffer I/O on preconnected units</h3>

<p>The environment variable named <code>GFORTRAN_UNBUFFERED_PRECONNECTED</code> controls
whether I/O on a preconnected unit (i.e. STDOUT or STDERR) is unbuffered.  If 
the first letter is &lsquo;<samp>y</samp>&rsquo;, &lsquo;<samp>Y</samp>&rsquo; or &lsquo;<samp>1</samp>&rsquo;, I/O is unbuffered.  This
will slow down small sequential reads and writes.  If the first letter
is &lsquo;<samp>n</samp>&rsquo;, &lsquo;<samp>N</samp>&rsquo; or &lsquo;<samp>0</samp>&rsquo;, I/O is buffered.  This is the default.
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