Average Memory Usage of some process

proc_mem.sh

#!/bin/bash

#ps --no-headers -o "rss,cmd" -C php-fpm7.4 | awk '{ sum+=$1 } END { printf ("%d%s\n", sum/NR/1024,"MB") }'
function chk() {
	name="$1"
	val=$(ps --no-headers -o "rss,cmd" -C "$name" | awk '{ sum+=$1 } END { printf ("%d%s\n", sum/NR/1024,"MB") }')
	printf " %10s |" $val
}

function header() {
	printf "| %-24s | %10s | %10s | %10s | %10s |" "Date" "Node" "Nginx" "PHP" "PHP-FPM"
	echo ""
}

function body() {
	printf "| %24s |" $now
	chk node
	chk nginx
	chk php
	chk php-fpm7.4
	echo ""
}


LOG_FILE="/var/log/proc_mem_$(date +%Y%m%d).log"

now=$(date +%Y-%m-%dT%T%z)
if [ "$1" = "--log" ];then
  LOG=1
else
  LOG=0
fi

if [ $LOG -eq 0 ]; then
	header
	body
else
   [ -f "$LOG_FILE" ] || header > "$LOG_FILE"
   body >> "$LOG_FILE"
fi

• Output

| Date                     |       Node |      Nginx |        PHP |    PHP-FPM |
| 2020-08-27T18:06:29+0000 |      144MB |       11MB |       53MB |       88MB |