You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
132 lines
5.8 KiB
HTML
132 lines
5.8 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
|
<html>
|
|
<!-- Created by GNU Texinfo 6.4, http://www.gnu.org/software/texinfo/ -->
|
|
<head>
|
|
<title>fwrite (The Red Hat newlib C Library)</title>
|
|
|
|
<meta name="description" content="fwrite (The Red Hat newlib C Library)">
|
|
<meta name="keywords" content="fwrite (The Red Hat newlib C Library)">
|
|
<meta name="resource-type" content="document">
|
|
<meta name="distribution" content="global">
|
|
<meta name="Generator" content="makeinfo">
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
|
|
<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="Stdio.html#Stdio" rel="up" title="Stdio">
|
|
<link href="getc.html#getc" rel="next" title="getc">
|
|
<link href="fwide.html#fwide" rel="prev" title="fwide">
|
|
<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="fwrite"></a>
|
|
<div class="header">
|
|
<p>
|
|
Next: <a href="getc.html#getc" accesskey="n" rel="next">getc</a>, Previous: <a href="fwide.html#fwide" accesskey="p" rel="prev">fwide</a>, Up: <a href="Stdio.html#Stdio" accesskey="u" rel="up">Stdio</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="fwrite_002c-fwrite_005funlocked_002d_002d_002dwrite-array-elements"></a>
|
|
<h3 class="section">4.32 <code>fwrite</code>, <code>fwrite_unlocked</code>—write array elements</h3>
|
|
<a name="index-fwrite"></a>
|
|
<a name="index-fwrite_005funlocked"></a>
|
|
<a name="index-_005ffwrite_005fr"></a>
|
|
<a name="index-_005ffwrite_005funlocked_005fr"></a>
|
|
<p><strong>Synopsis</strong>
|
|
</p><div class="example">
|
|
<pre class="example">#include <stdio.h>
|
|
size_t fwrite(const void *restrict <var>buf</var>, size_t <var>size</var>,
|
|
size_t <var>count</var>, FILE *restrict <var>fp</var>);
|
|
|
|
#define _BSD_SOURCE
|
|
#include <stdio.h>
|
|
size_t fwrite_unlocked(const void *restrict <var>buf</var>, size_t <var>size</var>,
|
|
size_t <var>count</var>, FILE *restrict <var>fp</var>);
|
|
|
|
#include <stdio.h>
|
|
size_t _fwrite_r(struct _reent *<var>ptr</var>, const void *restrict <var>buf</var>, size_t <var>size</var>,
|
|
size_t <var>count</var>, FILE *restrict <var>fp</var>);
|
|
|
|
#include <stdio.h>
|
|
size_t _fwrite_unlocked_r(struct _reent *<var>ptr</var>, const void *restrict <var>buf</var>, size_t <var>size</var>,
|
|
size_t <var>count</var>, FILE *restrict <var>fp</var>);
|
|
|
|
</pre></div>
|
|
<p><strong>Description</strong><br>
|
|
<code>fwrite</code> attempts to copy, starting from the memory location
|
|
<var>buf</var>, <var>count</var> elements (each of size <var>size</var>) into the file or
|
|
stream identified by <var>fp</var>. <code>fwrite</code> may copy fewer elements than
|
|
<var>count</var> if an error intervenes.
|
|
</p>
|
|
<p><code>fwrite</code> also advances the file position indicator (if any) for
|
|
<var>fp</var> by the number of <em>characters</em> actually written.
|
|
</p>
|
|
<p><code>fwrite_unlocked</code> is a non-thread-safe version of <code>fwrite</code>.
|
|
<code>fwrite_unlocked</code> may only safely be used within a scope
|
|
protected by flockfile() (or ftrylockfile()) and funlockfile(). This
|
|
function may safely be used in a multi-threaded program if and only
|
|
if they are called while the invoking thread owns the (FILE *)
|
|
object, as is the case after a successful call to the flockfile() or
|
|
ftrylockfile() functions. If threads are disabled, then
|
|
<code>fwrite_unlocked</code> is equivalent to <code>fwrite</code>.
|
|
</p>
|
|
<p><code>_fwrite_r</code> and <code>_fwrite_unlocked_r</code> are simply reentrant versions of the
|
|
above that take an additional reentrant structure argument: <var>ptr</var>.
|
|
</p>
|
|
<br>
|
|
<p><strong>Returns</strong><br>
|
|
If <code>fwrite</code> succeeds in writing all the elements you specify, the
|
|
result is the same as the argument <var>count</var>. In any event, the
|
|
result is the number of complete elements that <code>fwrite</code> copied to
|
|
the file.
|
|
</p>
|
|
<br>
|
|
<p><strong>Portability</strong><br>
|
|
ANSI C requires <code>fwrite</code>.
|
|
</p>
|
|
<p><code>fwrite_unlocked</code> is a BSD extension also provided by GNU libc.
|
|
</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>
|
|
|
|
<hr>
|
|
<div class="header">
|
|
<p>
|
|
Next: <a href="getc.html#getc" accesskey="n" rel="next">getc</a>, Previous: <a href="fwide.html#fwide" accesskey="p" rel="prev">fwide</a>, Up: <a href="Stdio.html#Stdio" accesskey="u" rel="up">Stdio</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>
|