Change hostname automatically with bash script

hostname_change.sh

#!/bin/bash

# Usage 
## chmod +x hostname_change.sh
## sudo ./hostname_change.sh new_hostname

if [ "$EUID" -ne 0 ]
  then echo "Please run as root."
  exit
fi

current="$(hostname)"
echo "Current hostname is $current"

ip="$(hostname -I | cut -d" " -f1 | xargs)"

newHostname=$1
echo "New hostname is $newHostname"

echo "Hostname change process has been started..."

echo "Step1 : hostnamectl running..."
hostnamectl set-hostname $newHostname
echo "Step1 successfully finished."

echo "Step2 : Writing new hostname to /etc/hosts"
echo "$ip  $newHostname" >> /etc/hosts
echo "Step2 successfully finished."

echo "Hostname successfully changed."
echo "Verifying..."
check=$(hostname)

if [[ "$newHostname" -eq "$check" ]]
then
    echo "Hostname successfully changed $current to $check"
    echo "Sucessfully verified. Goodbye!"
fi

sudo ./hostname_change.sh new_ip

should be

sudo ./hostname_change.sh new_hostname

Hi!,

Thanks for pointing out the error.

I corrected the relevant part 👍 😺

Simply adding to /etc/hosts is not correct. It leaves the most important line intact:
127.0.1.1 oldhostname