|
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124 |
- <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
- <html>
- <!-- Created by GNU Texinfo 6.5, http://www.gnu.org/software/texinfo/ -->
- <head>
- <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
- <title>ecvt (The Red Hat newlib C Library)</title>
-
- <meta name="description" content="ecvt (The Red Hat newlib C Library)">
- <meta name="keywords" content="ecvt (The Red Hat newlib C Library)">
- <meta name="resource-type" content="document">
- <meta name="distribution" content="global">
- <meta name="Generator" content="makeinfo">
- <link href="index.html#Top" rel="start" title="Top">
- <link href="Document-Index.html#Document-Index" rel="index" title="Document Index">
- <link href="Document-Index.html#SEC_Contents" rel="contents" title="Table of Contents">
- <link href="Stdlib.html#Stdlib" rel="up" title="Stdlib">
- <link href="gcvt.html#gcvt" rel="next" title="gcvt">
- <link href="div.html#div" rel="prev" title="div">
- <style type="text/css">
- <!--
- a.summary-letter {text-decoration: none}
- blockquote.indentedblock {margin-right: 0em}
- blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
- blockquote.smallquotation {font-size: smaller}
- div.display {margin-left: 3.2em}
- div.example {margin-left: 3.2em}
- div.lisp {margin-left: 3.2em}
- div.smalldisplay {margin-left: 3.2em}
- div.smallexample {margin-left: 3.2em}
- div.smalllisp {margin-left: 3.2em}
- kbd {font-style: oblique}
- pre.display {font-family: inherit}
- pre.format {font-family: inherit}
- pre.menu-comment {font-family: serif}
- pre.menu-preformatted {font-family: serif}
- pre.smalldisplay {font-family: inherit; font-size: smaller}
- pre.smallexample {font-size: smaller}
- pre.smallformat {font-family: inherit; font-size: smaller}
- pre.smalllisp {font-size: smaller}
- span.nolinebreak {white-space: nowrap}
- span.roman {font-family: initial; font-weight: normal}
- span.sansserif {font-family: sans-serif; font-weight: normal}
- ul.no-bullet {list-style: none}
- -->
- </style>
-
-
- </head>
-
- <body lang="en">
- <a name="ecvt"></a>
- <div class="header">
- <p>
- Next: <a href="gcvt.html#gcvt" accesskey="n" rel="next">gcvt</a>, Previous: <a href="div.html#div" accesskey="p" rel="prev">div</a>, Up: <a href="Stdlib.html#Stdlib" accesskey="u" rel="up">Stdlib</a> [<a href="Document-Index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Document-Index.html#Document-Index" title="Index" rel="index">Index</a>]</p>
- </div>
- <hr>
- <a name="ecvt_002c-ecvtf_002c-fcvt_002c-fcvtf_002d_002d_002ddouble-or-float-to-string"></a>
- <h3 class="section">2.13 <code>ecvt</code>, <code>ecvtf</code>, <code>fcvt</code>, <code>fcvtf</code>—double or float to string</h3>
- <a name="index-ecvt"></a>
- <a name="index-ecvtf"></a>
- <a name="index-fcvt"></a>
- <a name="index-fcvtf"></a>
- <p><strong>Synopsis</strong>
- </p><div class="example">
- <pre class="example">#include <stdlib.h>
-
- char *ecvt(double <var>val</var>, int <var>chars</var>, int *<var>decpt</var>, int *<var>sgn</var>);
- char *ecvtf(float <var>val</var>, int <var>chars</var>, int *<var>decpt</var>, int *<var>sgn</var>);
-
- char *fcvt(double <var>val</var>, int <var>decimals</var>,
- int *<var>decpt</var>, int *<var>sgn</var>);
- char *fcvtf(float <var>val</var>, int <var>decimals</var>,
- int *<var>decpt</var>, int *<var>sgn</var>);
-
- </pre></div>
- <p><strong>Description</strong><br>
- <code>ecvt</code> and <code>fcvt</code> produce (null-terminated) strings of digits
- representating the <code>double</code> number <var>val</var>.
- <code>ecvtf</code> and <code>fcvtf</code> produce the corresponding character
- representations of <code>float</code> numbers.
- </p>
- <p>(The <code>stdlib</code> functions <code>ecvtbuf</code> and <code>fcvtbuf</code> are reentrant
- versions of <code>ecvt</code> and <code>fcvt</code>.)
- </p>
- <p>The only difference between <code>ecvt</code> and <code>fcvt</code> is the
- interpretation of the second argument (<var>chars</var> or <var>decimals</var>).
- For <code>ecvt</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>fcvt</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>ecvt</code> and <code>fcvt</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.
- </p>
- <br>
- <p><strong>Returns</strong><br>
- All four functions return a pointer to the new string containing a
- character representation of <var>val</var>.
- </p>
- <br>
- <p><strong>Portability</strong><br>
- None of these functions are 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>.
- </p>
- <br>
- <br>
- <hr>
- <div class="header">
- <p>
- Next: <a href="gcvt.html#gcvt" accesskey="n" rel="next">gcvt</a>, Previous: <a href="div.html#div" accesskey="p" rel="prev">div</a>, Up: <a href="Stdlib.html#Stdlib" accesskey="u" rel="up">Stdlib</a> [<a href="Document-Index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Document-Index.html#Document-Index" title="Index" rel="index">Index</a>]</p>
- </div>
-
-
-
- </body>
- </html>
|