Set ubuntu hostname via script using sed

sethostname.sh

#!/bin/bash

# Set $chostname to current hostname 
chostname=$(cat /etc/hostname)

# Display current hostname
echo "Current hostname is '$chostname'"

# Set $newhostname as new hostname 
echo "Enter new hostname: "
read newhostname

# Change the hostname value in /etc/hostname and /etc/hosts files
sudo sed -i "s/$chostname/$newhostname/g" /etc/hostname
sudo sed -i "s/$chostname/$newhostname/g" /etc/hosts

# Display new hostname
echo "Your new hostname is $newhostname"

# Reboot the system
read -s -n 1 -p "Press any key to reboot!"
sudo reboot