As a macOS administrator, you'll occasionally encounter frozen GUI sessions where the user can't interact with the system through normal means. While sudo reboot is the nuclear option, here are more surgical approaches to logout just the graphical session.

The cleanest way to logout a specific user session:

sudo launchctl bootout gui/$(id -u username)

For the current user:

sudo launchctl bootout gui/$UID

For a more graceful logout that allows save prompts:

osascript -e 'tell application "System Events" to log out'

When all else fails, restart the WindowServer process:

sudo pkill -9 WindowServer

Note this will immediately terminate all GUI applications without save prompts.

To replicate Apple Remote Desktop's logout capability:

#!/bin/bash
TARGET_USER="username"
USER_ID=$(id -u "$TARGET_USER")
sudo launchctl bootout gui/$USER_ID
sleep 5
if pgrep -u $USER_ID > /dev/null; then
    sudo pkill -9 -u $USER_ID
fi

For stubborn sessions, you may need to combine approaches:

sudo killall -9 loginwindow WindowServer Finder

Then restart the services:

sudo launchctl kickstart -k system/com.apple.loginwindow

Always consider that forced logouts may cause data loss in unsaved documents. Where possible:

1. Attempt graceful methods first
2. Notify the user if possible
3. Document the procedures

When troubleshooting unresponsive macOS systems, administrators often need to terminate GUI sessions remotely without full reboots. The key distinction lies between forced termination and user-friendly approaches that preserve workflows.

For immediate session termination when systems are completely locked:

# Kill the WindowServer process (forces logout)
sudo killall -9 WindowServer

# Alternative via launchctl
sudo launchctl bootout gui/$(id -u)

Warning: These methods immediately terminate all GUI applications without saving.

For cooperative logout that mimics the Apple menu behavior:

# Trigger standard logout dialog
osascript -e 'tell app "System Events" to log out'

# With 60-second delay and cancel option
osascript -e 'tell app "System Events" to log out with options {dialogTimeout:60, canCancel:true}'

For system administration scripts, consider these robust approaches:

# List active GUI sessions
log list | grep -E 'session.*gui'

# Targeted logout by UID
sudo launchctl bootout gui/501

Combine these techniques with SSH for remote administration:

ssh admin@mac.example.com "osascript -e 'tell app \"System Events\" to log out'"

For enterprise deployments, create plist files in /var/db/com.apple.xpc.launchd to manage session policies.

Always precede forced logouts with filesystem sync:

sync && sudo killall -9 WindowServer

Consider implementing a 30-second warning via say or Notification Center before executing destructive commands.