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<html><head><title>Exercises (Learning Perl, 3rd Edition)</title><link rel="stylesheet" type="text/css" href="../style/style1.css" /><meta name="DC.Creator" content="Randal L. Schwartz and Tom Phoenix" /><meta name="DC.Format" content="text/xml" scheme="MIME" /><meta name="DC.Language" content="en-US" /><meta name="DC.Publisher" content="O'Reilly & Associates, Inc." /><meta name="DC.Source" scheme="ISBN" content="0596001320L" /><meta name="DC.Subject.Keyword" content="stuff" /><meta name="DC.Title" content="Learning Perl, 3rd Edition" /><meta name="DC.Type" content="Text.Monograph" /></head><body bgcolor="#ffffff"><img alt="Book Home" border="0" src="gifs/smbanner.gif" usemap="#banner-map" /><map name="banner-map"><area shape="rect" coords="1,-2,616,66" href="index.htm" alt="Learning Perl, 3rd Edition" /><area shape="rect" coords="629,-11,726,25" href="jobjects/fsearch.htm" alt="Search this book" /></map><div class="navbar"><table width="684" border="0"><tr><td align="left" valign="top" width="228"><a href="ch14_07.htm"><img alt="Previous" border="0" src="../gifs/txtpreva.gif" /></a></td><td align="center" valign="top" width="228"><a href="index.htm"></a></td><td align="right" valign="top" width="228"><a href="ch15_01.htm"><img alt="Next" border="0" src="../gifs/txtnexta.gif" /></a></td></tr></table></div><h2 class="sect1">14.8. Exercises</h2><p>See <a href="appa_13.htm#lperl3-APP-A-SECT-13">Section A.13, "Answers to Chapter 14 Exercises"</a> for answers to the followingexercises:</p><ol><li><p>[6] Write a program that changes to some particular (hardcoded)directory, like the system's <em class="emphasis">root</em>directory, then executes the <i class="command">ls -l</i> command to geta long-format directory listing in that directory. (If you use anon-Unix system, use your own system's command to get adetailed directory listing.)</p></li><li><p>[10] Modify the previous program to send the output of the command toa file called <em class="filename">ls.out</em> in the current directory.The error output should go to a file called<em class="filename">ls.err</em>. (You don't need to do anythingspecial about the fact that either of these files may end up beingempty.)</p></li><li><p>[8] Write a program to parse the output of the<i class="command">date</i> command to determine the current day of theweek. If the day of the week is a weekday, print <tt class="literal">get towork</tt>, otherwise print <tt class="literal">go play</tt>. Theoutput of the <i class="command">date</i> command begins with<tt class="literal">Mon</tt> on a Monday.<a href="#FOOTNOTE-331">[331]</a> If you don't have a <i class="command">date</i> commandon your non-Unix system, make a fake little program that simplyprints a string like <i class="command">date</i> might print. We'lleven give you this two-line program if you promise not to ask us howit works<a name="INDEX-994" /><a name="INDEX-995" /><a name="INDEX-996" />:</p><blockquote class="footnote"> <a name="FOOTNOTE-331" /><p>[331]At least when thedays of the week are being given in English. You might have to adjustaccordingly if that's not the case on your system.</p></blockquote><blockquote><pre class="code">#!/usr/bin/perlprint localtime( ) . "\n";</pre></blockquote></li></ol><hr width="684" align="left" /><div class="navbar"><table width="684" border="0"><tr><td align="left" valign="top" width="228"><a href="ch14_07.htm"><img alt="Previous" border="0" src="../gifs/txtpreva.gif" /></a></td><td align="center" valign="top" width="228"><a href="index.htm"><img alt="Home" border="0" src="../gifs/txthome.gif" /></a></td><td align="right" valign="top" width="228"><a href="ch15_01.htm"><img alt="Next" border="0" src="../gifs/txtnexta.gif" /></a></td></tr><tr><td align="left" valign="top" width="228">14.7. Sending and Receiving Signals</td><td align="center" valign="top" width="228"><a href="index/index.htm"><img alt="Book Index" border="0" src="../gifs/index.gif" /></a></td><td align="right" valign="top" width="228">15. Strings and Sorting</td></tr></table></div><hr width="684" align="left" /><img alt="Library Navigation Links" border="0" src="../gifs/navbar.gif" usemap="#library-map" /><p><p><font size="-1"><a href="copyrght.htm">Copyright © 2002</a> O'Reilly & Associates. All rights reserved.</font></p><map name="library-map"><area shape="rect" coords="1,0,85,94" href="../index.htm"><area shape="rect" coords="86,1,178,103" href="../lwp/index.htm"><area shape="rect" coords="180,0,265,103" href="../lperl/index.htm"><area shape="rect" coords="267,0,353,105" href="../perlnut/index.htm"><area shape="rect" coords="354,1,446,115" href="../prog/index.htm"><area shape="rect" coords="448,0,526,132" href="../tk/index.htm"><area shape="rect" coords="528,1,615,119" href="../cookbook/index.htm"><area shape="rect" coords="617,0,690,135" href="../pxml/index.htm"></map></body></html>⌨️ 快捷键说明
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