1. macOS
   1. Modifying all host names

macOS

Modifying all host names

#!/bin/bash
# This script changes the hostname on macOS by updating:
# - ComputerName: The user-friendly name seen in Sharing preferences.
# - LocalHostName: The Bonjour name used on the local network (must be sanitized).
# - HostName: The system’s POSIX name.
# - NetBIOSName: Used for SMB file sharing.
#
# Usage: sudo ./change_hostname.sh NewHostname

# Check if the new hostname is provided
if [ "$#" -ne 1 ]; then
    echo "Usage: sudo $0 <new_hostname>"
    exit 1
fi

NEW_HOSTNAME="$1"

# Sanitize the new hostname for LocalHostName (Bonjour) requirements:
# - Convert to lowercase, remove invalid characters (keeping only letters, numbers, and hyphens).
SANITIZED_HOSTNAME=$(echo "$NEW_HOSTNAME" | tr '[:upper:]' '[:lower:]' | tr -cd '[:alnum:]-')

echo "Changing hostname to: $NEW_HOSTNAME"
echo "Using sanitized LocalHostName: $SANITIZED_HOSTNAME"

# Change the ComputerName (visible in Sharing settings)
sudo scutil --set ComputerName "$NEW_HOSTNAME"

# Change the LocalHostName (used for Bonjour)
sudo scutil --set LocalHostName "$SANITIZED_HOSTNAME"

# Change the HostName (the underlying POSIX hostname)
sudo scutil --set HostName "$NEW_HOSTNAME"

# Optionally, change the NetBIOS name for SMB file sharing
sudo defaults write /Library/Preferences/SystemConfiguration/com.apple.smb.server NetBIOSName -string "$NEW_HOSTNAME"

echo "Hostname successfully updated!"
echo "A reboot might be required for all changes to fully take effect."