Perhaps something has changed in all these years: using PERL 5.14 and Apache virtual hosting all of these gives you a different result: 

$CGI->virtual_host() returns DNS name ex. www.my.address.com
$ENV{'SERVER_NAME'} returns "localhost"
$ENV{'HTTP_HOST'} returns "localhost:8001"

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The actual values of course depends on you environment setting.

In reply to Re^3: (2) to $Env{'HTTP_HOST'} or to $Env{'SERVER_NAME'}, that is the question. by Anonymous Monk
in thread to $Env{'HTTP_HOST'} or to $Env{'SERVER_NAME'}, that is the question. by JK_Bean

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