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<!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) 2001-2003 The Open Group, All Rights Reserved --><title>gettimeofday</title></head><body bgcolor="white"><script type="text/javascript" language="JavaScript" src="../jscript/codes.js"></script><basefont size="3"> <a name="gettimeofday"></a> <a name="tag_03_254"></a><!-- gettimeofday --> <!--header start--><center><font size="2">The Open Group Base Specifications Issue 6<br>IEEE Std 1003.1, 2003 Edition<br>Copyright © 2001-2003 The IEEE and The Open Group, All Rights reserved.</font></center><!--header end--><hr size="2" noshade><h4><a name="tag_03_254_01"></a>NAME</h4><blockquote>gettimeofday - get the date and time</blockquote><h4><a name="tag_03_254_02"></a>SYNOPSIS</h4><blockquote class="synopsis"><div class="box"><code><tt><sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border="0"> #include <<a href="../basedefs/sys/time.h.html">sys/time.h</a>><br><br> int gettimeofday(struct timeval *restrict</tt> <i>tp</i><tt>, void *restrict</tt> <i>tzp</i><tt>); <img src="../images/opt-end.gif" alt="[Option End]" border="0"></tt></code></div><tt><br></tt></blockquote><h4><a name="tag_03_254_03"></a>DESCRIPTION</h4><blockquote><p>The <i>gettimeofday</i>() function shall obtain the current time, expressed as seconds and microseconds since the Epoch, andstore it in the <b>timeval</b> structure pointed to by <i>tp</i>. The resolution of the system clock is unspecified.</p><p>If <i>tzp</i> is not a null pointer, the behavior is unspecified.</p></blockquote><h4><a name="tag_03_254_04"></a>RETURN VALUE</h4><blockquote><p>The <i>gettimeofday</i>() function shall return 0 and no value shall be reserved to indicate an error.</p></blockquote><h4><a name="tag_03_254_05"></a>ERRORS</h4><blockquote><p>No errors are defined.</p></blockquote><hr><div class="box"><em>The following sections are informative.</em></div><h4><a name="tag_03_254_06"></a>EXAMPLES</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_254_07"></a>APPLICATION USAGE</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_254_08"></a>RATIONALE</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_254_09"></a>FUTURE DIRECTIONS</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_254_10"></a>SEE ALSO</h4><blockquote><p><a href="ctime.html"><i>ctime</i>()</a> , <a href="ftime.html"><i>ftime</i>()</a> , the Base Definitions volume ofIEEE Std 1003.1-2001, <a href="../basedefs/sys/time.h.html"><i><sys/time.h></i></a></p></blockquote><h4><a name="tag_03_254_11"></a>CHANGE HISTORY</h4><blockquote><p>First released in Issue 4, Version 2.</p></blockquote><h4><a name="tag_03_254_12"></a>Issue 5</h4><blockquote><p>Moved from X/OPEN UNIX extension to BASE.</p></blockquote><h4><a name="tag_03_254_13"></a>Issue 6</h4><blockquote><p>The DESCRIPTION is updated to refer to "seconds since the Epoch" rather than "seconds since 00:00:00 UTC (CoordinatedUniversal Time), January 1 1970" for consistency with other <i>time</i> functions.</p><p>The <b>restrict</b> keyword is added to the <i>gettimeofday</i>() prototype for alignment with the ISO/IEC 9899:1999standard.</p></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>⌨️ 快捷键说明
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