ch13_05.htm
来自「by Randal L. Schwartz and Tom Phoenix I」· HTM 代码 · 共 54 行
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<html><head><title>Modifying Permissions (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="ch13_04.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="ch13_06.htm"><img alt="Next" border="0" src="../gifs/txtnexta.gif" /></a></td></tr></table></div><h2 class="sect1">13.5. Modifying Permissions</h2><p>The Unix <i class="command">chmod</i><a name="INDEX-916" /> command changes the<a name="INDEX-917" />permissionson a file or directory. Similarly, Perl has the<tt class="literal">chmod</tt><a name="INDEX-918" /> function to perform this task:</p><blockquote><pre class="code">chmod 0755, "fred", "barney";</pre></blockquote><p>As with many of the operating system interface functions,<tt class="literal">chmod</tt> returns the number of items successfullyaltered, and when used with a single argument, sets<tt class="literal">$!</tt> in a sensible way for error messages when itfails. The first parameter is the Unix permission value (even fornon-Unix versions of Perl). For the same reasons we presented earlierin describing <tt class="literal">mkdir</tt>, this value is usuallyspecified in octal.</p><p>Symbolic permissions (like <span class="option">+x</span> or<span class="option">go=u-w</span>) accepted by the Unix<i class="command">chmod</i> command are not valid for the<tt class="literal">chmod</tt> function.<a href="#FOOTNOTE-296">[296]</a></p><blockquote class="footnote"> <a name="FOOTNOTE-296" /><p>[296]Unlessyou've installed and invoke the <tt class="literal">File::chmod</tt>module from CPAN, which can apparently upgrade the<tt class="literal">chmod</tt> operator to understand symbolic modevalues.</p> </blockquote><hr width="684" align="left" /><div class="navbar"><table width="684" border="0"><tr><td align="left" valign="top" width="228"><a href="ch13_04.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="ch13_06.htm"><img alt="Next" border="0" src="../gifs/txtnexta.gif" /></a></td></tr><tr><td align="left" valign="top" width="228">13.4. Making and Removing Directories</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">13.6. Changing Ownership</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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