archlinux update /etc/motd with systemd

update_motd.service

[Unit]
Description=Update motd
After=sshdgenkeys.service

[Service]
ExecStart=
ExecStart=/usr/local/bin/update_motd.sh
Restart=always

[Install]
WantedBy=multi-user.target

update_motd.sh

#!/bin/bash
#Script to update motd with relevant information.

#Define output file
motd="/etc/motd"

# Collect information
# $USER is automatically defined
HOSTNAME=`uname -n`
KERNEL=`uname -r`
CPU=`awk -F '[ :][ :]+' '/^model name/ { print $2; exit; }' /proc/cpuinfo`
#CPU=`uname -p`
ARCH=`uname -m`
# Upgradable packages:
PACMAN=`pacman -Qu | wc -l`
# Here you should enter your disks data:
DISC=`df -h | grep /dev/sda1 | awk '{print $5 }'`
# How many memory your system uses:
MEMORY1=`free -t -m | grep "Mem" | awk '{print $3" MB";}'`
MEMORY2=`free -t -m | grep "Mem" | awk '{print $2" MB";}'`
PSA=`ps -Afl | wc -l`
PSU=`ps U $USER h | wc -l`

#Time of day
HOUR=$(date +"%H")
if [ $HOUR -lt 12  -a $HOUR -ge 0 ]
then   TIME="morning"
elif [ $HOUR -lt 17 -a $HOUR -ge 12 ]
then   TIME="afternoon"
else   TIME="evening"
fi

#System uptime
uptime=`cat /proc/uptime | cut -f1 -d.`
upDays=$((uptime/60/60/24))
upHours=$((uptime/60/60%24))
upMins=$((uptime/60%60))
upSecs=$((uptime%60))


#System load
LOAD1=`cat /proc/loadavg | awk {'print $1'}`
LOAD5=`cat /proc/loadavg | awk {'print $2'}`
LOAD15=`cat /proc/loadavg | awk {'print $3'}`

#Color variables
W="\033[00;37m"
B="\033[01;36m"
R="\033[01;34m"
X="\033[01;37m"
A="\033[01;32m"

#Clear screen before motd
clear > $motd

echo -e "
        $A. $X
       $A/#\ $X                     _     $A _ _
      $A/###\ $X      __ _ _ __ ___| |__  $A| (_)_ __  _   ___  __ 
     $A/#####\ $X    / _' | '__/ __| '_ \ $A| | | '_ \| | | \ \/ /
    $A/##.-.##\ $X  | (_| | | | (__| | | |$A| | | | | | |_| |>  <  
   $A/##(   )##\ $X  \__,_|_|  \___|_| |_|$A|_|_|_| |_|\__,_/_/\_\\
  $A/#.--   --.#\ $X
 $A/'           '\ $B
" >> $motd

echo -e "$R===============================================================" >> $motd
echo -e "
                __
   ___     __.::::::..__
,:::::::odP\"::::::::::\"\"Yb.
 \`::::d'\":::d::d b::L:::::\`b.   ___
.:::.d':d::d:,P   b:Ib:I::::\`b::::::.
 7;' I:d .dP\"      bI bIb::::\`b::::::'
 '   V'     ___     b __ b::::I\`:::::.
    ( cI  \"\"   \"\"   \"\"  \`.b:_P   \"\`: '
     \ I                   V \`.
      d'    ,\"\"\"\"\"\"\"\".      (, )
      b     :        :     ,  /
    .-\"b    :        ;   .d..\`.
   <::::Y._  \`._____/  ,;\"\`::::\ 
   /::::' \`\"\"=..__..,=\"'    \:.|\"
   \"|:'        )\"\" (         \|\`
" >> $motd
echo -e "$R===============================================================" >> $motd
echo -e "       $W Good $TIME $B , $W welcome to $B $HOSTNAME                " >> $motd
echo -e "       $R KERNEL $W= $KERNEL                                 " >> $motd
echo -e "       $R CPU    $W= $CPU                                    " >> $motd
echo -e "       $R HOSTNAME $W= $HOSTNAME                             " >> $motd
echo -e "       $R ARCH $W= $ARCH                                     " >> $motd
echo -e "       $R SYSTEM $W= $PACMAN packages can be updated         " >> $motd
echo -e "       $R USERS $W= Currently `users | wc -w` users logged on " >> $motd
echo -e "$R===============================================================" >> $motd
echo -e "       $R CPU Usage $W= $LOAD1 1 min $LOAD5 5 min $LOAD15 15 min " >> $motd
# You should check whether acpi or lm_sensors works.
# This is for acpi:
# echo -e "       $R CPU Temperature $W= `acpi -t | cut -f4 -d' '` C " >> $motd
# This is for lm_sensors:
echo -e "       $R CPU Temperature $W= `sensors | grep "CPU Temperature:" | awk '{ print $3 }'`" >> $motd
echo -e "       $R Memory Used $W= $MEMORY1 / $MEMORY2                " >> $motd
echo -e "       $R Swap in use $W= `free -m | tail -n 1 | awk '{print $3}'` MB " >> $motd
echo -e "       $R Processes $W= You are running $PSU of $PSA processes " >> $motd
echo -e "       $R System Uptime $W= $upDays days $upHours hours $upMins minutes $upSecs seconds " >> $motd
echo -e "       $R Disk Space Used $W= $DISC                          " >> $motd
echo -e "$R===============================================================" >> $motd
echo -e "$X" >> $motd