Bash script to track peak system memory usage (mem + swap)

peakmem.sh

#!/bin/bash
max_mem=0
while [ true ]; do
  # awk trick from https://stackoverflow.com/a/450821
  mem="$(free --giga | sed 's/ \+/ /g' | cut -d ' ' -f 3 | tail -n +2 | awk '{s+=$1} END {print s}')"
  if [ "$mem" -gt "$max_mem" ]; then
    max_mem="$mem"
    echo "new peak ${max_mem}GB at $(date)"
  fi
  sleep 0.1
done