151 lines
6.2 KiB
HTML
151 lines
6.2 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
|
|
<html>
|
|
<head>
|
|
<meta name="generator" content="HTML Tidy, see www.w3.org">
|
|
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
|
|
<link type="text/css" rel="stylesheet" href="style.css"><!-- Generated by The Open Group's rhtm tool v1.2.1 -->
|
|
<!-- Copyright (c) 2001 The Open Group, All Rights Reserved -->
|
|
<title>fwrite</title>
|
|
</head>
|
|
<body bgcolor="white">
|
|
<script type="text/javascript" language="JavaScript" src="../jscript/codes.js">
|
|
</script>
|
|
|
|
<basefont size="3"> <a name="fwrite"></a> <a name="tag_03_205"></a><!-- fwrite -->
|
|
<!--header start-->
|
|
<center><font size="2">The Open Group Base Specifications Issue 6<br>
|
|
IEEE Std 1003.1-2001<br>
|
|
Copyright © 2001 The IEEE and The Open Group, All Rights reserved.</font></center>
|
|
|
|
<!--header end-->
|
|
<hr size="2" noshade>
|
|
<h4><a name="tag_03_205_01"></a>NAME</h4>
|
|
|
|
<blockquote>fwrite - binary output</blockquote>
|
|
|
|
<h4><a name="tag_03_205_02"></a>SYNOPSIS</h4>
|
|
|
|
<blockquote class="synopsis">
|
|
<p><code><tt>#include <<a href="../basedefs/stdio.h.html">stdio.h</a>><br>
|
|
<br>
|
|
size_t fwrite(const void *restrict</tt> <i>ptr</i><tt>, size_t</tt> <i>size</i><tt>, size_t</tt> <i>nitems</i><tt>,<br>
|
|
FILE *restrict</tt> <i>stream</i><tt>);<br>
|
|
</tt></code></p>
|
|
</blockquote>
|
|
|
|
<h4><a name="tag_03_205_03"></a>DESCRIPTION</h4>
|
|
|
|
<blockquote>
|
|
<div class="box"><sup>[<a href="javascript:open_code('CX')">CX</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]"
|
|
border="0"> The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the
|
|
requirements described here and the ISO C standard is unintentional. This volume of IEEE Std 1003.1-2001 defers to
|
|
the ISO C standard. <img src="../images/opt-end.gif" alt="[Option End]" border="0"></div>
|
|
|
|
<p>The <i>fwrite</i>() function shall write, from the array pointed to by <i>ptr</i>, up to <i>nitems</i> elements whose size is
|
|
specified by <i>size</i>, to the stream pointed to by <i>stream</i>. For each object, <i>size</i> calls shall be made to the <a
|
|
href="../functions/fputc.html"><i>fputc</i>()</a> function, taking the values (in order) from an array of <b>unsigned char</b>
|
|
exactly overlaying the object. The file-position indicator for the stream (if defined) shall be advanced by the number of bytes
|
|
successfully written. If an error occurs, the resulting value of the file-position indicator for the stream is unspecified.</p>
|
|
|
|
<p><sup>[<a href="javascript:open_code('CX')">CX</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border="0"> The
|
|
<i>st_ctime</i> and <i>st_mtime</i> fields of the file shall be marked for update between the successful execution of
|
|
<i>fwrite</i>() and the next successful completion of a call to <a href="../functions/fflush.html"><i>fflush</i>()</a> or <a href=
|
|
"../functions/fclose.html"><i>fclose</i>()</a> on the same stream, or a call to <a href="../functions/exit.html"><i>exit</i>()</a>
|
|
or <a href="../functions/abort.html"><i>abort</i>()</a>. <img src="../images/opt-end.gif" alt="[Option End]" border="0"></p>
|
|
</blockquote>
|
|
|
|
<h4><a name="tag_03_205_04"></a>RETURN VALUE</h4>
|
|
|
|
<blockquote>
|
|
<p>The <i>fwrite</i>() function shall return the number of elements successfully written, which may be less than <i>nitems</i> if a
|
|
write error is encountered. If <i>size</i> or <i>nitems</i> is 0, <i>fwrite</i>() shall return 0 and the state of the stream
|
|
remains unchanged. Otherwise, if a write error occurs, the error indicator for the stream shall be set, <sup>[<a href=
|
|
"javascript:open_code('CX')">CX</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border="0"> and
|
|
<i>errno</i> shall be set to indicate the error. <img src="../images/opt-end.gif" alt="[Option End]" border="0"></p>
|
|
</blockquote>
|
|
|
|
<h4><a name="tag_03_205_05"></a>ERRORS</h4>
|
|
|
|
<blockquote>
|
|
<p>Refer to <a href="fputc.html"><i>fputc</i>()</a> .</p>
|
|
</blockquote>
|
|
|
|
<hr>
|
|
<div class="box"><em>The following sections are informative.</em></div>
|
|
|
|
<h4><a name="tag_03_205_06"></a>EXAMPLES</h4>
|
|
|
|
<blockquote>
|
|
<p>None.</p>
|
|
</blockquote>
|
|
|
|
<h4><a name="tag_03_205_07"></a>APPLICATION USAGE</h4>
|
|
|
|
<blockquote>
|
|
<p>Because of possible differences in element length and byte ordering, files written using <i>fwrite</i>() are
|
|
application-dependent, and possibly cannot be read using <a href="../functions/fread.html"><i>fread</i>()</a> by a different
|
|
application or by the same application on a different processor.</p>
|
|
</blockquote>
|
|
|
|
<h4><a name="tag_03_205_08"></a>RATIONALE</h4>
|
|
|
|
<blockquote>
|
|
<p>None.</p>
|
|
</blockquote>
|
|
|
|
<h4><a name="tag_03_205_09"></a>FUTURE DIRECTIONS</h4>
|
|
|
|
<blockquote>
|
|
<p>None.</p>
|
|
</blockquote>
|
|
|
|
<h4><a name="tag_03_205_10"></a>SEE ALSO</h4>
|
|
|
|
<blockquote>
|
|
<p><a href="ferror.html"><i>ferror</i>()</a> , <a href="fopen.html"><i>fopen</i>()</a> , <a href="printf.html"><i>printf</i>()</a>
|
|
, <a href="putc.html"><i>putc</i>()</a> , <a href="puts.html"><i>puts</i>()</a> , <a href="write.html"><i>write</i>()</a> , the
|
|
Base Definitions volume of IEEE Std 1003.1-2001, <a href="../basedefs/stdio.h.html"><i><stdio.h></i></a></p>
|
|
</blockquote>
|
|
|
|
<h4><a name="tag_03_205_11"></a>CHANGE HISTORY</h4>
|
|
|
|
<blockquote>
|
|
<p>First released in Issue 1. Derived from Issue 1 of the SVID.</p>
|
|
</blockquote>
|
|
|
|
<h4><a name="tag_03_205_12"></a>Issue 6</h4>
|
|
|
|
<blockquote>
|
|
<p>Extensions beyond the ISO C standard are marked.</p>
|
|
|
|
<p>The following changes are made for alignment with the ISO/IEC 9899:1999 standard:</p>
|
|
|
|
<ul>
|
|
<li>
|
|
<p>The <i>fwrite</i>() prototype is updated.</p>
|
|
</li>
|
|
|
|
<li>
|
|
<p>The DESCRIPTION is updated to clarify how the data is written out using <a href=
|
|
"../functions/fputc.html"><i>fputc</i>()</a>.</p>
|
|
</li>
|
|
</ul>
|
|
</blockquote>
|
|
|
|
<div class="box"><em>End of informative text.</em></div>
|
|
|
|
<hr>
|
|
<hr size="2" noshade>
|
|
<center><font size="2"><!--footer start-->
|
|
UNIX ® is a registered Trademark of The Open Group.<br>
|
|
POSIX ® is a registered Trademark of The IEEE.<br>
|
|
[ <a href="../mindex.html">Main Index</a> | <a href="../basedefs/contents.html">XBD</a> | <a href=
|
|
"../utilities/contents.html">XCU</a> | <a href="../functions/contents.html">XSH</a> | <a href="../xrat/contents.html">XRAT</a>
|
|
]</font></center>
|
|
|
|
<!--footer end-->
|
|
<hr size="2" noshade>
|
|
</body>
|
|
</html>
|
|
|