macOS User Login and Uptime Report Bash Script

#!/bin/bash
# Title: Detailed macOS User Last Login Checker with System Uptime
# Description:
# This script lists human user accounts (UID ≥ 500) on macOS and displays detailed information about their last login session.
# It also shows the current system uptime at the top.
#
# The output includes:
#   - System Uptime: How long the machine has been running since the last boot.
#   - Username     : The account name.
#   - Terminal     : The terminal device used during login.
#   - Login Date   : The date of the login (Day Month Date).
#   - Login Time   : The time when the login occurred.
#   - Login Status : Indicates if the session is still active or has ended.
#
# Note: "Never logged in" is shown if no login record exists.
#
# Retrieve and display system uptime
systemUptime=$(uptime)
echo "System Uptime: $systemUptime"
echo ""

# Print header for the login details
echo "Username | Terminal | Login Date       | Login Time | Login Status"
echo "---------------------------------------------------------------------"

# List users with their UniqueIDs and process each one.
dscl . -list /Users UniqueID | while read username uid; do
    if [ "$uid" -ge 500 ]; then
        # Retrieve the most recent login record for the user
        loginInfo=$(last -1 "$username" | head -n 1)
        
        # Check if there is a valid login record
        if echo "$loginInfo" | grep -q "wtmp begins"; then
            echo "$username |    -     |       -        |     -    | Never logged in"
        else
            # Parse the login record:
            #   Field 1: Username (redundant here)
            #   Field 2: Terminal (e.g., ttys000)
            #   Fields 3-5: Login Date (e.g., "Mon Feb 17")
            #   Field 6: Login Time (e.g., "05:44")
            #   Fields 7+: Login Status (e.g., "still logged in" or the session end time)
            terminal=$(echo "$loginInfo" | awk '{print $2}')
            login_date=$(echo "$loginInfo" | awk '{print $3, $4, $5}')
            login_time=$(echo "$loginInfo" | awk '{print $6}')
            login_status=$(echo "$loginInfo" | cut -d' ' -f7-)
            
            # Output the parsed details in a table-like format
            printf "%-8s | %-8s | %-16s | %-10s | %s\n" "$username" "$terminal" "$login_date" "$login_time" "$login_status"
        fi
    fi
done

# Legend:
#   System Uptime - How long the system has been running since the last boot.
#   Username      - The account name.
#   Terminal      - The terminal device used during login.
#   Login Date    - The date of the login (Day Month Date).
#   Login Time    - The time of the login.
#   Login Status  - The current status of the login session.