script to set the hostname in macOS using scutil for HostName, LocalHostname, ComputerName to the same value

macos-set-hostname.sh

#!/bin/bash

# Function to display usage information
usage() {
    echo "Usage: $0 <new-hostname>"
    exit 1
}

# Check if the user has provided a hostname argument
if [ $# -eq 0 ]; then
    usage
fi

NEW_HOSTNAME=$1

# Ensure the script is run with sudo for administrative privileges
if [[ $EUID -ne 0 ]]; then
    echo "This script must be run as root."
    sudo "$0" "$@"
    exit $?
fi

# Set the hostname, local hostname, and computer name
sudo scutil --set HostName "$NEW_HOSTNAME"
sudo scutil --set LocalHostName "$NEW_HOSTNAME"
sudo scutil --set ComputerName "$NEW_HOSTNAME"

# Flush DNS cache to ensure new settings take effect
dscacheutil -flushcache

echo "Hostname updated successfully to $NEW_HOSTNAME"