change_hostname.sh

# Check if sudo permission is available, else exit
if [ `id -u` != "0" ]
then
    echo '[ERROR] please run with sudo'
    exit
fi

# Retrieve new hostname from args
if [ -z "$1" ]
then
    echo "usage: $0 HOSTNAME"
else
    # Assign existing hostname to $hostn
    hostn=$(cat /etc/hostname); newhost=$1
    echo "[INFO] updating '$hostn' > '$1'"
    sed -i "s/$hostn/$newhost/g" /etc/hosts
    sed -i "s/$hostn/$newhost/g" /etc/hostname
    hostnamectl set-hostname $newhost 
fi