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<html><head><title>User::grent (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="User::grent"><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_45.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_47.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">32.46. User::grent</h2><p><blockquote><pre class="programlisting">use User::grent;$gr = getgrgid(0) or die "No group zero";if ($gr->name eq "wheel" && @{$gr->members} > 1) { print "gid zero name wheel, with other members";}$gr = getgr($whoever); # Accepts both string or number.use User::grent ':FIELDS';getgrgid(0) or die "No group zero";if ($gr_name eq "wheel" && @gr_members > 1) { print "gid zero name wheel, with other members";}</pre></blockquote>This module's default exports override the core <tt class="literal">getgrent</tt>,<tt class="literal">getgruid</tt>, and <tt class="literal">getgrnam</tt> functions, replacing them with versionsthat return a <tt class="literal">User::grent</tt> object (or <tt class="literal">undef</tt> on failure). Thisobject has methods that access the like-named structure fields from theC library's <tt class="literal">struct group</tt> out of <em class="emphasis">grp.h</em>; namely <tt class="literal">name</tt>, <tt class="literal">passwd</tt>,<tt class="literal">gid</tt>, and <tt class="literal">members</tt> (not <tt class="literal">mem</tt> as in C!). The first three returnscalars, the last an array reference. You may also import thestructure fields into your own namespace as regular variables using the"<tt class="literal">:FIELDS</tt>" import tag, although this still overrides your corefunctions. The variables (three scalars and an array) are named witha preceding "<tt class="literal">gr_</tt>". The <tt class="literal">getgr</tt> function is a simple frontend switchthat forwards any numeric argument to <tt class="literal">getgrgid</tt> and any string argument to<tt class="literal">getgrnam</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_45.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_47.htm"><img src="../gifs/txtnexta.gif" alt="Next" border="0"></a></td></tr><tr><td align="left" valign="top" width="172">32.45. Time::localtime</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">32.47. User::pwent</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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