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<a name="ecvtbuf_002c-fcvtbuf_002d_002d_002ddouble-or-float-to-string"></a>
<h3 class="section">2.15 <code>ecvtbuf</code>, <code>fcvtbuf</code>&mdash;double or float to string</h3>
<a name="index-ecvtbuf"></a>
<a name="index-fcvtbuf"></a>
<p><strong>Synopsis</strong>
</p><div class="example">
<pre class="example">#include &lt;stdio.h&gt;

char *ecvtbuf(double <var>val</var>, int <var>chars</var>, int *<var>decpt</var>,
    int *<var>sgn</var>, char *<var>buf</var>);

char *fcvtbuf(double <var>val</var>, int <var>decimals</var>, int *<var>decpt</var>,
    int *<var>sgn</var>, char *<var>buf</var>);

</pre></div>
<p><strong>Description</strong><br>
<code>ecvtbuf</code> and <code>fcvtbuf</code> produce (null-terminated) strings
of digits representating the <code>double</code> number <var>val</var>.
</p>
<p>The only difference between <code>ecvtbuf</code> and <code>fcvtbuf</code> is the
interpretation of the second argument (<var>chars</var> or
<var>decimals</var>). For <code>ecvtbuf</code>, the second argument <var>chars</var>
specifies the total number of characters to write (which is
also the number of significant digits in the formatted string,
since these two functions write only digits). For <code>fcvtbuf</code>,
the second argument <var>decimals</var> specifies the number of
characters to write after the decimal point; all digits for
the integer part of <var>val</var> are always included.
</p>
<p>Since <code>ecvtbuf</code> and <code>fcvtbuf</code> write only digits in the
output string, they record the location of the decimal point
in <code>*<var>decpt</var></code>, and the sign of the number in <code>*<var>sgn</var></code>.
After formatting a number, <code>*<var>decpt</var></code> contains the number
of digits to the left of the decimal point.  <code>*<var>sgn</var></code>
contains <code>0</code> if the number is positive, and <code>1</code> if it is
negative.  For both functions, you supply a pointer <var>buf</var> to
an area of memory to hold the converted string.
</p>
<br>
<p><strong>Returns</strong><br>
Both functions return a pointer to <var>buf</var>, the string
containing a character representation of <var>val</var>.
</p>
<br>
<p><strong>Portability</strong><br>
Neither function is ANSI C.
</p>
<p>Supporting OS subroutines required: <code>close</code>, <code>fstat</code>, <code>isatty</code>,
<code>lseek</code>, <code>read</code>, <code>sbrk</code>, <code>write</code>.
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