linux cpu 使用率计算

#!/bin/bash

# 获取CPU使用率的函数
get_cpu_usage() {
    local cpu_stats=$(cat /proc/stat | grep '^cpu ')
    local user=$(echo $cpu_stats | awk '{print $2}')
    local nice=$(echo $cpu_stats | awk '{print $3}')
    local system=$(echo $cpu_stats | awk '{print $4}')
    local idle=$(echo $cpu_stats | awk '{print $5}')

    local total_cpu_time=$((user + nice + system + idle))
    local idle_time=$idle

    echo "$total_cpu_time $idle_time"
}

# 获取初始CPU时间
read initial_total initial_idle < <(get_cpu_usage)

sleep 1

# 获取1秒后的CPU时间
read final_total final_idle < <(get_cpu_usage)

# 计算CPU使用率
local total_diff=$((final_total - initial_total))
local idle_diff=$((final_idle - initial_idle))

local cpu_usage=$(echo "scale=2; (1 - ($idle_diff / $total_diff)) * 100" | bc)

echo "CPU Usage: $cpu_usage%"