FQDN of the server thru CLI

Hi All I'm writing a bunch of cron scripts that send reports periodically using phpmailer. I'm having a hard time trying to find the FQDN of the server. I need that information to construct the from address for the emails. The $_ENV['HOSTNAME'] works only if the script is executed manually. the cron does not pass the HOSTNAME env variable to the scripts. When executed from the CLI, the $_SERVER['HOSTNAME'] does not have the fqdn, but just the hostname part of the FQDN. Unless i hard code the corntab file with HOSTNAME=fqdn i do not want to hardcode the hostname anywhere as these script will be copied onto many servers. is there a way i can find the fully qualified domain name thru PHP? Thanks /V