Create Admin User - MAC

#!/bin/bash

echo "Create macOS Local Administrator Account"
echo "=========================================="

#version check
varOSMaj=$(sw_vers -productVersion | awk '{split ($0,a,"."); print a[1]}')
varOSMin=$(sw_vers -productVersion | awk '{split ($0,a,"."); print a[2]}')

if [ "$varOSMaj" -eq "10" ]
then
	if [ "$varOSMin" -lt "15" ]

			echo "! WARNING: This script has not been successfully tested on macOS versions"
			echo "  lower than 10.15 and may not work with those devices. Execution halted."
			exit 1
	fi

fi

#search for an unused userID, starting at 502
varExit=0
varUserID=501 
until [ "$varExit" -eq "1" ]
do
	varUserID=$((varUserID+1))
	dscl . -list /Users UniqueID | grep -q " $varUserID$"
	varExit=$?
	echo "- Trying ID #$varUserID..."
	sleep 1
done

echo "  SUCCESS: User ID #$varUserID is free for use."
echo "- Creating a new user: $usrUN ($usrRN)"
echo "--------------------------------"
dscl . -create /Users/$usrUN
dscl . -create /Users/$usrUN UserShell /bin/bash
dscl . -create /Users/$usrUN RealName "$usrRN"
dscl . -create /Users/$usrUN UniqueID $varUserID
dscl . -create /Users/$usrUN PrimaryGroupID 80
dscl . -create /Users/$usrUN NFSHomeDirectory /Users/$usrUN
dscl . -create /Users/$usrUN Picture "/Library/User Pictures/Instruments/Turntable.tif"
dscl . -append /Groups/admin GroupMembership $usrUN
dscl . -create /Users/$usrUN "authentication_authority" ";ShadowHash;"
dscl . -passwd /Users/$usrUN $usrPWD
cp -vR /System/Library/User\ Template/English.lproj/ /Users/$usrUN > /dev/null 2>&1
chown -R $varUserID:staff /Users/$usrUN

echo "- New user account created!"
echo "  It may be wise to reboot the device before signing into it."