#!/bin/sh

# Module showing overall CPU usage as a percentage.
# Cache in tmpfs to improve speed and reduce SSD load
cache=/tmp/cpubarscache

# Extract CPU stats (total time and idle time)
cpu_stats=$(awk '/^cpu / {print $2 + $3 + $4 + $5, $5}' /proc/stat)

# Check if cache exists, if not, initialize it
[ ! -f $cache ] && echo "$cpu_stats" > "$cache"

# Read previous CPU stats from cache
prev_stats=$(cat "$cache")

# Calculate CPU usage percentage and exit immediately
echo "$cpu_stats $prev_stats" | awk '{
    total_diff = $1 - $3
    idle_diff = $2 - $4
    usage = 100 * (1 - idle_diff / total_diff)
    printf " %.1f%%\n", usage
    exit  # Terminate script after printing the first line
}'

# Update cache with current stats
echo "$cpu_stats" > "$cache"