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If you are on a machine that supports membership in multiple groups simultaneously, gives a space separated list of groups you are in. The first number is the one returned by getegid(), and the subsequent ones by getgroups(), one of which may be the same as the first number.</p> <p>Similarly, a value assigned to <code>$)</code> must also be a space-separated list of numbers. The first number sets the effective gid, and the rest (if any) are passed to setgroups(). To get the effect of an empty list for setgroups(), just repeat the new effective gid; that is, to force an effective gid of 5 and an effectively empty setgroups() list, say <code> $) = "5 5" </code>.</p> <p>You can change both the effective gid and the real gid at the same time by using POSIX::setgid() (use only a single numeric argument). Changes to $) require a check to $! to detect any possible errors after an attempted change.</p> <p>(Mnemonic: parentheses are used to <i>group</i> things. The effective gid is the group that's <i>right</i> for you, if you're running setgid.)</p> <p><code>$<</code>, <code>$></code>, <code>$(</code> and <code>$)</code> can be set only on machines that support the corresponding <i>set[re][ug]id()</i> routine. <code>$(</code> and <code>$)</code> can be swapped only on machines supporting setregid().</p> </dd> </dl> </div> <div id="footer"> <p>Perldoc Browser is maintained by Dan Book (<a href="https://metacpan.org/author/DBOOK">DBOOK</a>). Please contact him via the <a href="https://github.com/Grinnz/perldoc-browser/issues">GitHub issue tracker</a> or <a href="mailto:dbook@cpan.org">email</a> regarding any issues with the site itself, search, or rendering of documentation.</p> <p>The Perl documentation is maintained by the Perl 5 Porters in the development of Perl. 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