X-Forwarded-For: client, proxy1, proxy2,.....

##</code><code>##

    my $ip = $ENV{'HTTP_X_FORWARDED_FOR'} || $ENV{'REMOTE_HOST'} || $ENV{'REMOTE_ADDR'};
    # HTTP_X_FORWARDED_FOR may be 'xxx.xxx.xxx.xxx, xxx.xxx.xxx.xxx'
    # originating client is left most IP. this split patches issues as some proxies
    # add space after IP and before ,
    ($ip) = split /\s*,/, $ip;