systemchecker.sh

#!/bin/bash

CPU=$(top -bn1 | grep "Cpu(s)" | awk '{print $2 + $4}')   # b - batch mode (print to terminal, not interactive); n1 - show 1 iteration and exit (no refreshing); $2 - for user cpu; $4 - for system cpu

MEMORY=$(free | grep Mem | awk '{print $3/$2 * 100.0}')

DISK=$(df -h / | awk 'NR==2 {print $5}') # h - for human-readable form 

UPTIME=$(uptime -p) # p - for human-readable form

TOP_PROCESSES=$(ps -eo pid,cmd,%cpu --sort=-%cpu | head -n 6) # e = aux; o - specifies output format by columns

echo "System Monitoring Report - $(date)"
echo "-----------------------------------------"
echo "CPU Usage: $CPU%"
echo "Memory Usage: $MEMORY%"
echo "Disk Usage: $DISK"
echo "Uptime: $UPTIME"
echo ""
echo "Top 5 Processes by CPU Usage"
echo "$TOP_PROCESSES"
echo "-----------------------------------------"