232 lines
6.4 KiB
HTML
232 lines
6.4 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
|
|
<html>
|
|
<head>
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
|
|
<meta name="Copyright" content="Copyright (c) 2006 by IBM Corporation">
|
|
<!-- Begin Header records -->
|
|
<title>adjtime()--Adjust System Clock</title>
|
|
<!-- All rights reserved. Licensed Materials Property of IBM -->
|
|
<!-- US Government Users Restricted Rights -->
|
|
<!-- Use, duplication or disclosure restricted by -->
|
|
<!-- GSA ADP Schedule Contract with IBM Corp. -->
|
|
<!-- Change History: -->
|
|
<!-- YYMMDD USERID Change description -->
|
|
<!-- End Header Records -->
|
|
<link rel="stylesheet" type="text/css" href="../rzahg/ic.css">
|
|
</head>
|
|
<body>
|
|
<!-- Java sync-link =================================================== -->
|
|
<script type="text/javascript" language="Javascript" src="../rzahg/synch.js">
|
|
</script>
|
|
|
|
<a name="Top_Of_Page"></a>
|
|
|
|
<h2>adjtime()--Adjust System Clock</h2>
|
|
|
|
<div class="box" style="width: 70%;">
|
|
<br>
|
|
Syntax
|
|
|
|
<pre>
|
|
#include <sys/time.h>
|
|
|
|
int adjtime (struct timeval *delta,
|
|
struct timeval *olddelta);
|
|
</pre>
|
|
|
|
<br>
|
|
Service Program Name: QWCTZUTC<br>
|
|
<!-- iddvc RMBR -->
|
|
<br>
|
|
Default Public Authority: *USE<br>
|
|
<!-- iddvc RMBR -->
|
|
<br>
|
|
Threadsafe: Yes<br>
|
|
<!-- iddvc RMBR -->
|
|
<br>
|
|
</div>
|
|
|
|
<p>The <strong>adjtime()</strong> function makes small adjustments to the system clock, either slowing it down or speeding it up by the time specified in the <em>delta</em> parameter up to a maximum of two hours. If <em>delta</em> is negative, the clock is slowed down by incrementing it more slowly than normal until the correction is complete. If <em>delta</em> is positive, the clock is sped up by incrementing it more quickly than normal until the correction is complete. If <em>olddelta</em> is not NULL, the amount of time still to be corrected from a previous <strong>adjtime()</strong> call is returned in the structure it points to.
|
|
</p>
|
|
|
|
<br>
|
|
<h3>Parameters</h3>
|
|
|
|
<dl>
|
|
<dt><strong>delta</strong></dt>
|
|
<dd>(Input)
|
|
<p>A pointer to a timeval structure that contains the amount of time for adjusting the clock.</p>
|
|
</dd>
|
|
|
|
<dt><strong>olddelta</strong></dt>
|
|
<dd>(Output)
|
|
<p>A pointer to a timeval structure that contains the amount of time still to be corrected from a previous call to <strong>adjtime()</strong>.</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<br>
|
|
<h3>Authorities and Locks</h3>
|
|
|
|
<dl>
|
|
<dt><em>Special Authority</em></dt>
|
|
<dd>*ALLOBJ<br>
|
|
<br>
|
|
</dd>
|
|
</dl>
|
|
|
|
<br>
|
|
<h3>Return Value</h3>
|
|
|
|
<table width="100%">
|
|
<tr>
|
|
<td width="5%" valign=top><strong>0</strong></td>
|
|
<td width="95%"><strong>adjtime()</strong> was successful. The requested adjustment was initiated and the value returned in the structure pointed to by the <em>olddelta</em> parameter is the amount of time still to be corrected from a previous <strong>adjtime()</strong>.</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td valign=top><strong>-1</strong></td>
|
|
<td><strong>adjtime()</strong> was not successful. The <em>errno</em> variable is set to indicate the error.</td>
|
|
</tr>
|
|
</table>
|
|
|
|
<br>
|
|
<br>
|
|
|
|
<h3>Error Conditions</h3>
|
|
|
|
<p>If <strong>adjtime()</strong> is not successful, <em>errno</em> usually indicates one of the following errors. Under some conditions, <em>errno</em> could indicate an error other than those listed here.</p>
|
|
|
|
<table cellpadding="5">
|
|
<!-- cols="15 85" -->
|
|
<tr>
|
|
<td align="left" valign="top"><em>[EACCES]</em></td>
|
|
<td align="left" valign="top">Permission denied.
|
|
<p>An attempt was made to access an object in a way forbidden by its object
|
|
access permissions.</p>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td align="left" valign="top"><em>[EINVAL]</em></td>
|
|
<td align="left" valign="top">An invalid parameter was found.
|
|
<p>A parameter passed to this function is not valid.</p>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td align="left" valign="top"><em>[EFAULT]</em></td>
|
|
<td align="left" valign="top">The address used for an argument is not correct.
|
|
<p>In attempting to use an argument in a call, the system detected an address
|
|
that is not valid.</p>
|
|
<p>While attempting to access a parameter passed to this function, the system
|
|
detected an address that is not valid.</p>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td align="left" valign="top"><em>[EPERM]</em></td>
|
|
<td align="left" valign="top">Operation not permitted.
|
|
<p>You must have appropriate privileges or be the owner of the object or other
|
|
resource to do the requested operation.</p>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td align="left" valign="top"><em>[ENOTSUP]</em></td>
|
|
<td align="left" valign="top">Operation not supported.
|
|
<p>The operation is not supported.</p>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td align="left" valign="top"><em>[EUNKNOWN]</em></td>
|
|
<td align="left" valign="top">Unknown system state.
|
|
<p>The operation failed because of an unknown system state. See any messages in
|
|
the job log and correct any errors that are indicated, then retry the
|
|
operation.</p>
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
|
|
<br>
|
|
|
|
<h3>Error Messages</h3>
|
|
|
|
<p>None.</p>
|
|
|
|
<br>
|
|
<h3>Related Information</h3>
|
|
|
|
<ul>
|
|
<li>The <<strong>sys/time.h</strong>> file (see <a href=
|
|
"unix13.htm">Header Files for UNIX-Type Functions</a>)<br>
|
|
<br>
|
|
</li>
|
|
|
|
<li><a href="gettod.htm">gettimeofday()--Get Current UTC Time</a><br>
|
|
<br>
|
|
</li>
|
|
|
|
<li><a href="settod.htm">settimeofday()--Set System Clock</a></li>
|
|
</ul>
|
|
|
|
<br>
|
|
<h3><a name="example.htm">Example</a></h3>
|
|
|
|
<p>See <a href="../apiref/aboutapis.htm#codedisclaimer">Code disclaimer information</a>
|
|
for information pertaining to code examples.</p>
|
|
|
|
<p>The following example initiates a system clock adjustment:</p>
|
|
|
|
<pre>
|
|
#include <sys/time.h>
|
|
#include <stdio.h>
|
|
#include <errno.h>
|
|
|
|
int main(int argc, char *argv[])
|
|
{
|
|
struct timeval adj, old;
|
|
int rc;
|
|
|
|
/* Speed up the clock by 1.5 seconds. */
|
|
adj.tv_sec=1;
|
|
adj.tv_usec=500000;
|
|
|
|
rc=adjtime(&adj, &old);
|
|
if(rc==0) {
|
|
printf("adjtime() successful. "
|
|
"Olddelta = %u.%06u\n",
|
|
old.tv_sec, old.tv_usec);
|
|
}
|
|
else {
|
|
printf("adjtime() failed, errno = %d\n",errno);
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
</pre>
|
|
|
|
<strong>Example Output:</strong>
|
|
|
|
<pre>
|
|
adjtime() successful. Olddelta = 0.000000
|
|
</pre>
|
|
|
|
<br>
|
|
<hr>
|
|
API introduced: V4R2
|
|
|
|
<hr>
|
|
<center>
|
|
<table cellpadding="2" cellspacing="2">
|
|
<tr align="center">
|
|
<td valign="middle" align="center"><a href="#Top_Of_Page">Top</a> | <a href=
|
|
"unix.htm">UNIX-Type APIs</a> | <a href="aplist.htm">APIs by category</a></td>
|
|
</tr>
|
|
</table>
|
|
</center>
|
|
</body>
|
|
</html>
|
|
|