ibm-information-center/dist/eclipse/plugins/i5OS.ic.apis_5.4.0.1/xdr_bytes.htm

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<title>xdr_bytes()--Translate between Counted Byte Arrays and Their XDR</title>
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<h2>xdr_bytes()--Translate between Counted Byte Arrays and Their XDR</h2>
<div class="box" style="width: 60%;">
<br>
&nbsp;&nbsp;Syntax<br>
<pre>
#include &lt;rpc/xdr.h&gt;
bool_t xdr_bytes(XDR *<em>xdrs</em>,
char **<em>sp</em>,
u_int *<em>sizep</em>,
const u_int <em>maxsize</em>);
</pre>
<br>
&nbsp;&nbsp;Service Program Name: QZNFTRPC<br>
<!-- iddvc RMBR -->
<br>
&nbsp;&nbsp;Default Public Authority: *USE<br>
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<br>
&nbsp;&nbsp;Threadsafe: No<br>
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<p>The <strong>xdr_bytes()</strong> function is a filter primitive that
translates between counted byte arrays and their external representations. This
function treats a subset of generic arrays in which the size of array elements
is known to be 1 and the external description of each element is built-in. The
length of the byte sequence is explicitly located in an unsigned integer. The
byte sequence is not ended by a null character. The external representation of
the bytes is the same as their internal representation.</p>
<br>
<h3>Parameters</h3>
<dl>
<dt><strong>xdrs</strong> &nbsp;(Input)&nbsp;</dt>
<dd>A pointer to the eXternal Data Representation (XDR) stream handle.<br>
<br>
</dd>
<dt><strong>sp</strong> &nbsp;(I/O)&nbsp;</dt>
<dd>The address of the pointer to the byte array. If *sp==NULL and the stream
is being decoded, then XDR allocates the needed amount of memory.<br>
<br>
</dd>
<dt><strong>sizep</strong> &nbsp;(I/O)&nbsp;</dt>
<dd>A pointer to the length of the byte area. The value of this parameter
cannot exceed the value of the <em>maxsize</em> parameter.<br>
<br>
</dd>
<dt><strong>maxsize</strong> &nbsp;(Input)&nbsp;</dt>
<dd>The maximum number of bytes allowed when XDR encodes or decodes
messages.</dd>
</dl>
<br>
<h3>Authorities</h3>
<p>No authorization is required.</p>
<br>
<h3>Return Value</h3>
<table cellpadding="5">
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<tr>
<td align="left" valign="top"><em>TRUE (1)</em></td>
<td align="left" valign="top">Successful</td>
</tr>
<tr>
<td align="left" valign="top"><em>FALSE (0)</em></td>
<td align="left" valign="top">Unsuccessful</td>
</tr>
</table>
<br>
<br>
<h3>Error Conditions</h3>
<p>None.</p>
<br>
<h3>Error Messages</h3>
<table width="100%" cellpadding="5">
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<tr>
<th align="left" valign="top">Message ID</th>
<th align="left" valign="top">Error Message Text</th>
</tr>
<tr>
<td width="15%" valign="top">CPE3418 E</td>
<td width="85%" valign="top">Possible APAR condition or hardware failure.</td>
</tr>
<tr>
<td align="left" valign="top">CPF3CF2 E</td>
<td align="left" valign="top">Error(s) occurred during running of &amp;1 API.</td>
</tr>
<tr>
<td align="left" valign="top">CPF9872 E</td>
<td align="left" valign="top">Program or service program &amp;1 in library &amp;2 ended.
Reason code &amp;3.</td>
</tr>
</table>
<br>
<br>
<h3>Example</h3>
<p>See <a href="../apiref/aboutapis.htm#codedisclaimer">Code disclaimer information</a>
for information pertaining to code examples.</p>
<p>The following example shows how <strong>xdr_bytes()</strong> is used:</p>
<pre>
#include &lt;stdio.h&gt;
#include &lt;values.h&gt;
#include &lt;xdr.h&gt;
#define ARRAY_SIZE 256
typedef struct xarray
{
int size;
char *p_array;
} xarray ;
bool_t xdr_xarray(XDR *xdrs, xarray *p_xarray )
{
/*
* Force XDR to allocate memory while decoding
*/
if((xdrs-&gt;x_op==XDR_DECODE)&amp;&amp;
(p_xarray-&gt;p_array!=NULL))
{
free(p_xarray-&gt;p_array);
p_xarray-&gt;p_array=NULL;
}
/*
* This code has a dual job :
* A) While decoding, it allocated memory, stores the decoded
* xarray in it, and updates size field in xarray
* struct.
* B) While decoding it stores xarray's size and the data
* itself in XDR.
*/
return <strong>xdr_bytes</strong>(
xdrs,
(&amp;(p_xarray-&gt;p_array)),
&amp;(p_xarray-&gt;size),
MAX_INT);
}
</pre>
<br>
<hr>
API introduced: V4R2
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