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<html><head><title>Time::Local (Programming Perl)</title><!-- STYLESHEET --><link rel="stylesheet" type="text/css" href="../style/style1.css"><!-- METADATA --><!--Dublin Core Metadata--><meta name="DC.Creator" content=""><meta name="DC.Date" content=""><meta name="DC.Format" content="text/xml" scheme="MIME"><meta name="DC.Generator" content="XSLT stylesheet, xt by James Clark"><meta name="DC.Identifier" content=""><meta name="DC.Language" content="en-US"><meta name="DC.Publisher" content="O'Reilly & Associates, Inc."><meta name="DC.Source" content="" scheme="ISBN"><meta name="DC.Subject.Keyword" content=""><meta name="DC.Title" content="Time::Local"><meta name="DC.Type" content="Text.Monograph"></head><body><!-- START OF BODY --><!-- TOP BANNER --><img src="gifs/smbanner.gif" usemap="#banner-map" border="0" alt="Book Home"><map name="banner-map"><AREA SHAPE="RECT" COORDS="0,0,466,71" HREF="index.htm" ALT="Programming Perl"><AREA SHAPE="RECT" COORDS="467,0,514,18" HREF="jobjects/fsearch.htm" ALT="Search this book"></map><!-- TOP NAV BAR --><div class="navbar"><table width="515" border="0"><tr><td align="left" valign="top" width="172"><a href="ch32_43.htm"><img src="../gifs/txtpreva.gif" alt="Previous" border="0"></a></td><td align="center" valign="top" width="171"><a href="ch32_01.htm">Chapter 32: Standard Modules</a></td><td align="right" valign="top" width="172"><a href="ch32_45.htm"><img src="../gifs/txtnexta.gif" alt="Next" border="0"></a></td></tr></table></div><hr width="515" align="left"><!-- SECTION BODY --><h2 class="sect1">32.44. Time::Local</h2><p><blockquote><pre class="programlisting">use Time::Local;$time = timelocal($sec,$min,$hours,$mday,$mon,$year);$time = timegm($sec,$min,$hours,$mday,$mon,$year);$time = timelocal(50, 45, 3, 18, 0, 73);print "Scalar localtime gives: ", scalar(localtime($time)), "\n";$time += 28 * 365.2425 * 24 * 60 * 60;print "Twenty-eight years of seconds later, it's now\n\t", scalar(localtime($time)), "\n";</pre></blockquote>This prints:<blockquote><pre class="programlisting">Scalar localtime gives: Thu Jan 18 03:45:50 1973Twenty-eight years of seconds later, it's now Wed Jan 17 22:43:26 2001</pre></blockquote>The <tt class="literal">Time::Local</tt> module provides two functions, <tt class="literal">timelocal</tt> and<tt class="literal">timegm</tt>, that work like inverse functions for the standard<tt class="literal">localtime</tt> and <tt class="literal">gmtime</tt> functions, respectively. That is, they takea list of numeric values for the various components of what<tt class="literal">localtime</tt> returns in list context and figure out what input to<tt class="literal">localtime</tt> would produce those values. You might do this if youwanted to compare or run calculations on two different dates. Although these are not general-purpose functions for parsing dates andtimes, if you can arrange to have your input in the right format, theyoften suffice. As you can see from the example above, however, timehas its oddities, and even simple calculations often fail to do the jobintended due to leap years, leap seconds, and the phase of the moon.Two large but fully featured CPAN modules address these issues andmore: <tt class="literal">Date::Calc</tt> and <tt class="literal">Date::Manip</tt>.</p><!-- BOTTOM NAV BAR --><hr width="515" align="left"><div class="navbar"><table width="515" border="0"><tr><td align="left" valign="top" width="172"><a href="ch32_43.htm"><img src="../gifs/txtpreva.gif" alt="Previous" border="0"></a></td><td align="center" valign="top" width="171"><a href="index.htm"><img src="../gifs/txthome.gif" alt="Home" border="0"></a></td><td align="right" valign="top" width="172"><a href="ch32_45.htm"><img src="../gifs/txtnexta.gif" alt="Next" border="0"></a></td></tr><tr><td align="left" valign="top" width="172">32.43. Text::Wrap</td><td align="center" valign="top" width="171"><a href="index/index.htm"><img src="../gifs/index.gif" alt="Book Index" border="0"></a></td><td align="right" valign="top" width="172">32.45. Time::localtime</td></tr></table></div><hr width="515" align="left"><!-- LIBRARY NAV BAR --><img src="../gifs/smnavbar.gif" usemap="#library-map" border="0" alt="Library Navigation Links"><p><font size="-1"><a href="copyrght.htm">Copyright © 2001</a> O'Reilly & Associates. All rights reserved.</font></p><map name="library-map"> <area shape="rect" coords="2,-1,79,99" href="../index.htm"><area shape="rect" coords="84,1,157,108" href="../perlnut/index.htm"><area shape="rect" coords="162,2,248,125" href="../prog/index.htm"><area shape="rect" coords="253,2,326,130" href="../advprog/index.htm"><area shape="rect" coords="332,1,407,112" href="../cookbook/index.htm"><area shape="rect" coords="414,2,523,103" href="../sysadmin/index.htm"></map><!-- END OF BODY --></body></html>⌨️ 快捷键说明
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