lastreboot.sh

#!/bin/bash

last_login=$(last -1 $USER | awk '{print $5,$6,$7}')  # Get the last login timestamp
last_boot=$(who -b | awk '{print $3,$4}')  # Get the system boot timestamp

if [[ $last_boot > $last_login ]]; then  # Compare timestamps
    echo "The system has rebooted since the last login."  
else
    echo "The system has not rebooted since the last login."
fi