or download this
# USAGE $0 {failover|normal|status} $1 {serial}
# Syntax: DRDNSfail.pl {failover|normal|status} {serial}
...
$ROOT_DIR = "/var/named/zone";
#----------------------------------------------------
`perl -pi -e 's/2007\d\d\d\d\d\d/$ARGV[0]/' $ROOT_DIR/* $Serial`;