https://twitter.com/lang_explorer/status/1393455859171086336

highest-cpu.sh

#!/usr/bin/env bash
#
# Threadhold 값 (30%) 이상 CPU 점유하고 있는 프로세스 중 가장 높은 CPU 점유하고 있는 프로세스 반환합니다.
# Better Touch Tool과 연동하여 TaskBar에 노출시키기 위해 사용하거나
# TextBar http://richsomerfield.com/apps/textbar/ 와 함께 사용할 수 있습니다.
# 5초에 한번 정도 실행하도록 설정하면 적당합니다.
#

# https://stackoverflow.com/questions/24129903/notifying-when-using-high-cpu-via-applescript-or-automator
SAMPLE_SIZE=2
DELAY_SECS=1
TOP_APP_NUM=10 # number of apps to sum up
CPU_THRESHOLD=30

# Check out this gist to understand what's going on
# https://gist.github.com/Sangdol/0a5f1125a5b3bd67ed1562c50bb7f451
#
# -l: samples / increase the number to ignore the first result which has 0% cpu.
# -s: deplay-secs
# -n: number of processes
# -F: Do not calculate statistics on shared libraries, also known as frameworks.
# -o: order by (desc)
# -stats: display keys
read -r name pct < <(/usr/bin/top -s $DELAY_SECS -l $((SAMPLE_SIZE + 1)) -n $TOP_APP_NUM -F -o cpu -stats cpu,pid,command | \
  # Select results after the header that has %CPU
  grep -A$TOP_APP_NUM "%CPU" | \
  # Delete the first block which has 0% as cpu result
  sed '1,/^--/d' | \
  # Remove headers
  grep -v "%CPU" | \
  # Remove borders between results
  grep -v "^--" | \
  # Sum up for each app based on pid
  # $1: cpu, $2: pid, $3, command
  awk '{cpu[$2]+=$1;app_name[$2]=$3} END {for (pid in cpu) printf("%s\t%s\n", app_name[pid], cpu[pid])}' | \
  # -n: number
  # -k: nth key
  sort -n -k2 | \
  tail -1)

pct=$(bc -l <<< "scale=1;$pct / $SAMPLE_SIZE")

# For debugging
# echo "$name $pct"

if (( ${pct%.*} >= CPU_THRESHOLD )); then
  msg="Process > $CPU_THRESHOLD%: $name ($pct%)"
  echo "$(date +"%Y-%m-%d %H:%M") $msg" >> "/usr/local/var/log/cpu-monitor.log"

  textbar="$name ($pct%)"
  echo "$textbar"
else
  echo "🌳"
fi