#!/usr/bin/env bash
##################################################
#
# Small helper script - part of Someguy123/someguy-scripts
# Outputs the current CPU usage to stdout in the form of "23.45%"
#
# Install into /usr/local/bin/cpu-usage
#
# Source: https://github.com/Someguy123/someguy-scripts
#
##################################################

OS="$(uname -s)"

if [[ "$OS" == "Darwin" ]]; then
    top -l 1 | grep -E "^CPU|^Phys" | head -n1 | awk '{print $3}'
elif [[ "$OS" == "Linux" ]]; then
    top -bn2 | grep "Cpu(s)" | sed "s/.*, *\([0-9.]*\)%* id.*/\1/" | awk '{print 100 - $1"%"}' | tail -n1
else
    echo "0%"
    >&2 echo " [!!!] Unsupported operating system '$OS' - Only Linux and OSX (Darwin) are supported"
    exit 1
fi