to $Env{'HTTP_HOST'} or to $Env{'SERVER_NAME'}, that is the question.

[JK_Bean]

When checking $Env{}, which is the proper key to use to see if the domain is www.myserver.com or myserver.com, or is there another more technically correct way do to this?

When I use either 'HTTP_HOST' or 'SERVER_NAME', I get the same result. I want to be safe so my code is more portable.

[dkubb]

IMHO, the best way to get at that information is through CGI.pm's method virtual_host():

use CGI;

my $cgi = CGI->new;

my $domain = $cgi->virtual_host;

It will attempt to Do The Right Thing in determing the virtual host's name. I believe it is cleaner, and more portable to use CGI's methods to access the CGI specific environment variables, than to access them directly by hand.

[RatArsed]

In reality, all that's going to do is give you $ENV{"HTTP_HOST"} (or $ENV{"SERVER_NAME"} in the highly unlikely event of the Host: request header being specified)

The Host header (read $ENV{"HTTP_HOST"}) which is manditory for HTTP/1.1 (and IIRC also for HTTP/1.0) specifies the host name for the request; this was designed specifically for "virtual hosting".

If you already have a CGI object floating about, then I'd recommend using $cgi->virtual_host. If you don't, it's probably easier to just use $ENV{"HTTP_HOST"}

--
RatArsed

[Anonymous Monk]

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"

The actual values of course depends on you environment setting.

[tune]

I do not get the same. HTTP_HOST gives the same server name as I typed in the Location box of my browser. It can be 'localhost' for example.
SERVER_NAME is the same everytime, hostname + domain, as it is registered in the machine's configuration.

--
tune

[wardk]

JK_Bean, just a heads up...you should be using $ENV{'HTTP_HOST'}, i.e. %Env should be %ENV.

[JK_Bean]

yes, you are right. that was a typo. my code does in fact use $ENV, all caps.