zshrc/zshps

# Prompt Shell builder
	# [1] Connection security
		# Connected on remote machine, via ssh (good).
		if [ -n "${SSH_CONNECTION}" ]; then 
		    CONNECTION_LEFT="%F{green}[%f"   
		    CONNECTION_RIGHT="%F{green}]%f"   
		# Connected on remote machine, not via ssh (bad).    
		elif [ "${DISPLAY%%:0*}" != "" ]; then
		    CONNECTION_LEFT="%K{white}%F{red}[%f%k"
		    CONNECTION_RIGHT="%K{white}%F{red}]%f%k"
		# Connected on local machine.
		else
		    CONNECTION_LEFT="["
		    CONNECTION_RIGHT="]"
		fi


	# [2] User type
		# Root
		if [[ ${USER} = "root" ]]; then
			USER_PS="%F{red}%n%f"
		# Admin
		elif groups | grep -qw prod; then
			USER_PS="%F{yellow}%n%f"
		# Normal
		else
			USER_PS="%B%F{black}%n%f%b"
		fi
	# [3] Random color "@"
		function random_color() {
			COLOR_DB=(black red green yellow blue magenta cyan white)
			RANDOM_COLOR_NO=$(shuf -i 0-15 -n 1)
			if [[ ${RANDOM_COLOR_NO} -le 7 ]]; then
				RANDOM_AT="%F{$COLOR_DB[$RANDOM_COLOR_NO]}@%f"
			else
				RANDOM_COLOR_NO=$(( ${RANDOM_COLOR_NO} - 8 ))
				RANDOM_AT="%B%F{$COLOR_DB[$RANDOM_COLOR_NO]}@%f%b"
			fi
		}

	# [4] System load indicator
		# Returns usage (script inspired by Paul Colby's cpu.sh script)
			function check_load() {
				while true; do
					unset DIFF_IDLE
					unset DIFF_TOTAL
					unset DIFF_USAGE
					unset TOTAL
					unset IDLE
					unset VALUE
					unset CPU
					for i in {1..2}; do
						CPU=(`sed -n 's/^cpu\s//p' /proc/stat`) 
						IDLE[$i]=${CPU[4]} # Just the idle CPU time.
						for VALUE in "${CPU[@]}"; do
							TOTAL[$i]=$((${TOTAL[$i]}+$VALUE))
						done
						if [ $i = 1 ]; then
							sleep 2
						fi
					done
					# Returns a color indicating system load.
					# Calculate the CPU usage since we last checked.
					DIFF_IDLE=$(( ${IDLE[2]} - ${IDLE[1]} ))
					DIFF_TOTAL=$(( ${TOTAL[2]} - ${TOTAL[1]} ))
					DIFF_USAGE=$(( (1000*($DIFF_TOTAL - $DIFF_IDLE) / $DIFF_TOTAL+5) / 10 ))
					echo $DIFF_USAGE > /dev/shm/DIFF_USAGE
				done
			}
			if [ ! -f /dev/shm/DIFF_USAGE ]; then
				echo 0 > /dev/shm/DIFF_USAGE
				chmod 777 /dev/shm/DIFF_USAGE
			fi
			if [ ! -f /dev/shm/DIFF_USAGE.pid ]; then
				echo 0 > /dev/shm/DIFF_USAGE.pid
				chmod 777 /dev/shm/DIFF_USAGE.pid
			fi
			if ! eval ps -p $(cat /dev/shm/DIFF_USAGE.pid) > /dev/null 2>&1; then
				check_load &
				echo $! > /dev/shm/DIFF_USAGE.pid
			fi
			function load_color() {
					# Load vars
						# Small load
						SLOAD=30
						# Medium load
						MLOAD=60
						# Large load
						LLOAD=80
					if [ $(cat /dev/shm/DIFF_USAGE) -gt ${LLOAD} ]; then
						LOAD="%F{red}%m%f"
					elif [ $(cat /dev/shm/DIFF_USAGE) -gt ${MLOAD} ]; then
						LOAD="%F{yellow}%m%f"
					elif [ $(cat /dev/shm/DIFF_USAGE) -gt ${SLOAD} ]; then
						LOAD="%F{green  }%m%f"
					else
						LOAD="%B%F{black}%m%f%b"
					fi
			}
		
			
	# [5] Disk space indicator
		function disk_color(){
			if [ ! -w "${PWD}" ] ; then
				DISK_COLOR=$fg[red]
				# No 'write' privilege in the current directory.
			elif [ -s "${PWD}" ] ; then
				local used=$(command df -P "$PWD" | awk 'END {print $5} {sub(/%/,"")}')
				if [ ${used} -gt 85 ]; then
					# Disk almost full (>85%)
					DISK="%F{red}%1~%f"
				elif [ ${used} -gt 60 ]; then
					# Free disk space almost gone
					DISK="%F{yellow}%1~%f"     
				else
					# Free disk space is ok
					DISK="%F{green}%1~%f"  
				fi
			else
				DISK="%B%F{black}%~%f%b"
				# Current directory is size '0' (like /proc, /sys etc).
			fi
		}
		
# PS builder
	function buildPS() {
		case ${TERM} in
			*linux | rxvt-unicode-256color | xterm)
				PS1="${CONNECTION_LEFT}${USER_PS}${RANDOM_AT}${LOAD}:${DISK}${CONNECTION_RIGHT}$ "
				PS2="$ "
				PS3="#?"
				PS4='[${LINENO}]+ '
			;;

			*)
				PS1="${CONNECTION_LEFT}${USER_PS}${RANDOM_AT}${LOAD}:${DISK}${CONNECTION_RIGHT}$ "
			;;
		esac
	}

precmd() {
	random_color
	load_color
	disk_color
	buildPS
}