OSX - Create Guest Account

#!/bin/sh

# Original concepts by Noel B. Alonso: https://gist.github.com/nbalonso/5696340
# and Rich Trouton: https://github.com/rtrouton/rtrouton_scripts/tree/master/rtrouton_scripts/create_custom_guest_account

# ---------------------------------------------------------
#   Set all Variables
# ---------------------------------------------------------

#----- Debugging
#bash -x ./[script_name.sh] for detailed script output
#bash -n ./[script_name.sh] for syntax checking
set -u   # verbose error checking during execution

#----- Standards
script="Create-Guest-Account"
now=$(date +"%m-%d-%Y %H:%M:%S")

#----- Executables
mkdir=$(which mkdir)
chown=$(which chown)
chmod=$(which chmod)
dscl=$(which dscl)
security=$(which security)
killall=$(which killall)

#----- Computations
OSVERS=$(sw_vers -productVersion | awk -F. '{print $2}')

#----- Assignments
USERNAME="Guest"            ## Account short name
DISPLAYNAME="Guest User"    ## Account name displayed in System Preferences
GUESTUID="600"
GUESTGROUPID="600"

#----- Set Logging
Log="/Library/Logs/Nike"
if [ ! -d "${Log}" ];
then
    $mkdir $Log
    $chown root:wheel $Log
    $chmod 777 $Log
fi
exec >> "${Log}"/"${script}".log 2>&1

#----------------------------------------------------------
#  Timestamp
#----------------------------------------------------------
echo ""
echo "##### $script"
echo "##### $now"

#----------------------------------------------------------
#  Script
#----------------------------------------------------------
if [[ ${OSVERS} -ge 9 ]]; then
    ${dscl} . -create /Users/"${USERNAME}"
    ${dscl} . -create /Users/"${USERNAME}" dsAttrTypeNative:_defaultLanguage en
    ${dscl} . -create /Users/"${USERNAME}" dsAttrTypeNative:_guest true
    ${dscl} . -create /Users/"${USERNAME}" dsAttrTypeNative:_writers__defaultLanguage "${USERNAME}"
    ${dscl} . -create /Users/"${USERNAME}" dsAttrTypeNative:_writers_UserCertificate "${USERNAME}"
    ${dscl} . -create /Users/"${USERNAME}" AuthenticationHint ''
    ${dscl} . -create /Users/"${USERNAME}" NFSHomeDirectory /Users/"${USERNAME}"

    #setting up an empty password and giving local Kerberos some time to process it
    ${dscl} . -passwd /Users/"${USERNAME}" "${USERNAME}"
    sleep 2

    ${dscl} . -create /Users/"${USERNAME}" Picture "/Library/User Pictures/Nature/Leaf.tif"
    ${dscl} . -create /Users/"${USERNAME}" PrimaryGroupID "${GUESTGROUPID}"
    ${dscl} . -create /Users/"${USERNAME}" RealName "${DISPLAYNAME}"
    ${dscl} . -create /Users/"${USERNAME}" RecordName "${USERNAME}"
    ${dscl} . -create /Users/"${USERNAME}" UniqueID "${GUESTUID}"
    ${dscl} . -create /Users/"${USERNAME}" UserShell /bin/bash
    ${security} add-generic-password -a "${USERNAME}" -s com.apple.loginwindow.guest-account -A -w "${USERNAME}" -D "application password" /Library/Keychains/System.keychain

#   Restart loginwindow
#   ${killall} loginwindow
else
    echo "Script requires an OS of OSX 10.9 or later to function."
fi

exit 0