#!/bin/bash

export LANG=en_US.UTF-8
LOG_PATH="/var/log/monitor"
LOG_NAME="cpu"
INTERVAL=60

function Init {
    local self_count=$(pgrep -cx "$(basename $0)")
    [ 0 -eq $? ] || exit 1
    [ 1 -eq $self_count ] || exit 1
    type sar > /dev/null || exit 1
    mkdir -p $LOG_PATH || exit 1
}

function Log {
    local msg="$1"
    local log_time="$(date +'%F %T')"
    local log_file="$LOG_PATH/$LOG_NAME-${log_time% *}.log"
    echo "$log_time $msg" >> $log_file
    cd $LOG_PATH && ls ${LOG_NAME}-* 2>/dev/null \
        | head -n -7 | xargs rm -f
}

function GetCPULoad {
    top -b -n 1 | sed -n '3p' | sed 's/^.*://' | tr , ' ' \
        | awk '{print $1,$3,$9,$7}'
}

function Main {
    sleep $INTERVAL
    Log "$(GetCPULoad)"
}

# start
Init
Main