defunkt

#!/bin/bash
# 
# Save in your .bash_profile then: isreg domain.com

function isreg {
  dig soa $1 | grep -q ^$1 && echo "Yes" || echo "No"
}

jseifer

#! /usr/bin/env ruby
# 
# Save in your path as "isreg" and chmod +x. Then: isreg domain.com
#
puts `whois #{ARGV[0]}` =~ /No match for \"#{ARGV[0]}\"/mi ? "No" : "Yes"

trey

$localServers = array('something.dev');
$stagingServers = array('something_else.com', 'and_another.com');
if (in_array($_SERVER['HTTP_HOST'], $localServers)) {
    // Development settings
} elseif (in_array($_SERVER['HTTP_HOST'], $stagingServers)) {
    // Staging settings
} else {
    // Production settings
}