Show total combined memory usage (virtual, resident and dirty) for processes matching the given grep arguments

memusage.sh

#!/bin/bash

# Show total memory usage of all processes matching the supplied grep arguments

if [ "$#" -lt "1" ]; then
  echo "Usage: $0 <grep arguments>" >&2
  exit 1
fi

function humanize() {
  val=$1

  if [ "$val" -gt "1024" ]; then
    val=`bc <<< "scale=2; ${val}/1024"`
    echo "$val MB"
    return
  fi
  echo "$val kB"
}

virtual=0
resident=0
dirty=0

while IFS= read -r pid; do
#  echo "$pid"
  mem=$(pmap -x "$pid" | grep total)

  virt=`echo $mem | awk '{print $3}'`
  if [ ! -z "$virt" ]; then
    virtual=$(($virtual + $virt))
  fi

  res=`echo $mem | awk '{print $4}'`
  if [ ! -z "$res" ]; then
    resident=$(($resident + $res))
  fi

  dirt=`echo $mem | awk '{print $5}'`
  if [ ! -z "$dirt" ]; then
    dirty=$(($dirty + $dirt))
  fi
done < <(ps aux | grep $@ | grep -v grep | awk '{print $2}')

virtual=$(humanize $virtual)
resident=$(humanize $resident)
dirty=$(humanize $dirty)

printf '%s %16s\n' "Virtual " "$virtual"
printf '%s %16s\n' "Resident" "$resident"
printf '%s %16s\n' "Dirty   " "$dirty"