149 lines
5.7 KiB
HTML
149 lines
5.7 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>calloc</title>
|
|
</head>
|
|
<body bgcolor="white">
|
|
<script type="text/javascript" language="JavaScript" src="../jscript/codes.js">
|
|
</script>
|
|
|
|
<basefont size="3"> <a name="calloc"></a> <a name="tag_03_48"></a><!-- calloc -->
|
|
<!--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_48_01"></a>NAME</h4>
|
|
|
|
<blockquote>calloc - a memory allocator</blockquote>
|
|
|
|
<h4><a name="tag_03_48_02"></a>SYNOPSIS</h4>
|
|
|
|
<blockquote class="synopsis">
|
|
<p><code><tt>#include <<a href="../basedefs/stdlib.h.html">stdlib.h</a>><br>
|
|
<br>
|
|
void *calloc(size_t</tt> <i>nelem</i><tt>, size_t</tt> <i>elsize</i><tt>);<br>
|
|
</tt></code></p>
|
|
</blockquote>
|
|
|
|
<h4><a name="tag_03_48_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>calloc</i>() function shall allocate unused space for an array of <i>nelem</i> elements each of whose size in bytes is
|
|
<i>elsize</i>. The space shall be initialized to all bits 0.</p>
|
|
|
|
<p>The order and contiguity of storage allocated by successive calls to <i>calloc</i>() is unspecified. The pointer returned if the
|
|
allocation succeeds shall be suitably aligned so that it may be assigned to a pointer to any type of object and then used to access
|
|
such an object or an array of such objects in the space allocated (until the space is explicitly freed or reallocated). Each such
|
|
allocation shall yield a pointer to an object disjoint from any other object. The pointer returned shall point to the start (lowest
|
|
byte address) of the allocated space. If the space cannot be allocated, a null pointer shall be returned. If the size of the space
|
|
requested is 0, the behavior is implementation-defined: the value returned shall be either a null pointer or a unique pointer.</p>
|
|
</blockquote>
|
|
|
|
<h4><a name="tag_03_48_04"></a>RETURN VALUE</h4>
|
|
|
|
<blockquote>
|
|
<p>Upon successful completion with both <i>nelem</i> and <i>elsize</i> non-zero, <i>calloc</i>() shall return a pointer to the
|
|
allocated space. If either <i>nelem</i> or <i>elsize</i> is 0, then either a null pointer or a unique pointer value that can be
|
|
successfully passed to <a href="../functions/free.html"><i>free</i>()</a> shall be returned. Otherwise, it shall return a null
|
|
pointer <sup>[<a href="javascript:open_code('CX')">CX</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border=
|
|
"0"> and set <i>errno</i> to indicate the error. <img src="../images/opt-end.gif" alt="[Option End]" border="0"></p>
|
|
</blockquote>
|
|
|
|
<h4><a name="tag_03_48_05"></a>ERRORS</h4>
|
|
|
|
<blockquote>
|
|
<p>The <i>calloc</i>() function shall fail if:</p>
|
|
|
|
<dl compact>
|
|
<dt>[ENOMEM]</dt>
|
|
|
|
<dd><sup>[<a href="javascript:open_code('CX')">CX</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border="0">
|
|
Insufficient memory is available. <img src="../images/opt-end.gif" alt="[Option End]" border="0"></dd>
|
|
</dl>
|
|
</blockquote>
|
|
|
|
<hr>
|
|
<div class="box"><em>The following sections are informative.</em></div>
|
|
|
|
<h4><a name="tag_03_48_06"></a>EXAMPLES</h4>
|
|
|
|
<blockquote>
|
|
<p>None.</p>
|
|
</blockquote>
|
|
|
|
<h4><a name="tag_03_48_07"></a>APPLICATION USAGE</h4>
|
|
|
|
<blockquote>
|
|
<p>There is now no requirement for the implementation to support the inclusion of <i><malloc.h></i>.</p>
|
|
</blockquote>
|
|
|
|
<h4><a name="tag_03_48_08"></a>RATIONALE</h4>
|
|
|
|
<blockquote>
|
|
<p>None.</p>
|
|
</blockquote>
|
|
|
|
<h4><a name="tag_03_48_09"></a>FUTURE DIRECTIONS</h4>
|
|
|
|
<blockquote>
|
|
<p>None.</p>
|
|
</blockquote>
|
|
|
|
<h4><a name="tag_03_48_10"></a>SEE ALSO</h4>
|
|
|
|
<blockquote>
|
|
<p><a href="free.html"><i>free</i>()</a> , <a href="malloc.html"><i>malloc</i>()</a> , <a href="realloc.html"><i>realloc</i>()</a>
|
|
, the Base Definitions volume of IEEE Std 1003.1-2001, <a href=
|
|
"../basedefs/stdlib.h.html"><i><stdlib.h></i></a></p>
|
|
</blockquote>
|
|
|
|
<h4><a name="tag_03_48_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_48_12"></a>Issue 6</h4>
|
|
|
|
<blockquote>
|
|
<p>Extensions beyond the ISO C standard are marked.<br>
|
|
</p>
|
|
|
|
<p>The following new requirements on POSIX implementations derive from alignment with the Single UNIX Specification:</p>
|
|
|
|
<ul>
|
|
<li>
|
|
<p>The setting of <i>errno</i> and the [ENOMEM] error condition are mandatory if an insufficient memory condition occurs.</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>
|
|
|