Flush DNS cache on Mac OS X

flush_dns_cache.sh

#! /bin/sh

# Flushes the DNS cache on Mac OS X
#
# From https://www.madboa.com/blog/2014/10/24/mac-dns-cache/
#
# Only tested on Yosemite.

MAC_OS_X_VERSION=$(sw_vers -productVersion | awk -F '.' '{print $1 "." $2}')

case "$MAC_OS_X_VERSION" in

10.1[0-9]) # Yosemite and above (fingers crossed).
    sudo discoveryutil udnsflushcaches
    ;;

10.[7-9])  # Lion, Mountain Lion, Mavericks.
    sudo killall -HUP mDNSResponder
    ;;

10.[5-6])  # Leopard, Snow Leopard.
    sudo dscacheutil -flushcache
    ;;

10.[1-4])  # Tiger and earlier (tribute to the early beginnings of OSX).
    sudo lookupd -flushcache
    ;;

*)
    echo "$0: error: Unknown Mac OS version: $MAC_OS_X_VERSION"
    ;;

esac