cpu-utilization-macos.sh

#!/usr/bin/env bash
# By ChatGPT and masterfully adapted by Arne Tarara. No rights reserved :)

iostat -w 1 -n 0 | awk -v date_cmd="gdate +%s%N"'
NR > 3 { # skips first 3 rows, which contain header data and first average-only measurement
 # Extract user, system, and idle CPU percentages
 user = $1
 sys = $2
 idle = $3

 # Calculate total CPU usage
 usage = 100 - idle

 # Get the current time in seconds with microseconds
 cmd = date_cmd
 cmd | getline current_time_ns
 close(cmd)

 # Calculate the time difference
 if (last_time_ns != "") {
 time_diff_ns = current_time_ns - last_time_ns
 } else {
 time_diff_ns = 1000000000 # No difference for the first line
 }

 # Print the time and CPU usage
 printf "%.9f %.2f\n", (time_diff_ns / 1000000000), usage

 # Store the current time as the last time for the next iteration
 last_time_ns = current_time_ns
}'