IP of server?

I want to base the database a PHP script uses on the IP address of the server running the script. What is the fastest way to get the IP address of the server from a script? I could use environment variables but they are unreliable (when run from cron for example, the environment doesn't have all the variables you would expect). I wrote the following function based on a Perl firewall script that uses ifconfig, but it has too much overhead to call every time I connect to the database. All I really want to do is add a conf variable to php.ini that gets read at startup and is cached from then on. Any ideas? Thanks! Lance ---- // string gethostaddress([string]) // // Returns the IP address of a network interface for the local host. // Returns false on error or if the address cannot be determined. // // Note: This function shells the ifconfig command so call sparingly. // function gethostaddress($interface = "eth0") { $inetaddr = false; // assume failure $ifconfig = /sbin/ifconfig $interface; if (ereg("inet addr:([.0-9]+)", $ifconfig, $ifconfigparts)) $inetaddr = $ifconfigparts[1]; return ($inetaddr) ? $inetaddr : false; }