这样的perl写法是指什么？解决办法

这样的perl写法是指什么？

Perl code

$cf = {    # configuration options    rfsbase      => "$top",    rpmipfx      => '/',    rpmdb        => '/var/lib/rpm',    rpmdir       => "$top/rpm",    rpm          => "$bdir/ltib/usr/bin/rpm",    rpmbuild     => "rpmbuild",    sudo         => "sudo",    dodrop       => 'yes',    prefix       => "/usr",    sysconfdir   => "/etc",};