ACSP Apps and Processes 2 — Questions and Answers

Question 1: Which macOS tool lets you view all running processes and their CPU/memory usage in a graphical interface?

Activity Monitor (Correct answer)
Console
System Information
Disk Utility

Correct answer: Activity Monitor

Activity Monitor displays all running processes, their CPU, memory, energy, disk, and network usage in a graphical window, making it the primary tool for monitoring and managing processes on macOS.

Activity Monitor (found in /Applications/Utilities/) provides a real-time view of all running processes. It shows CPU usage, memory pressure, energy impact, disk read/write, and network activity. You can also use it to force-quit unresponsive applications. The Memory tab's memory pressure graph is particularly useful for diagnosing RAM issues.

Question 2: What is the purpose of the macOS Launch Services database?

It maps file types and URL schemes to the applications that open them (Correct answer)
It stores all installed app licenses
It manages background login items
It controls app sandboxing permissions

Correct answer: It maps file types and URL schemes to the applications that open them

The Launch Services database maps file types (UTIs) and URL schemes to registered applications, determining which app opens a given file or URL by default.

Launch Services (lsregister) maintains a database of all applications and their associated file types and URL schemes. When the database becomes corrupt, you may see wrong app associations or apps not appearing in Open With menus. It can be rebuilt using the lsregister command-line tool or by using third-party utilities. On Apple silicon Macs, this database is stored in a protected location.

Question 3: A user's application consistently crashes at launch after a macOS update. Which folder should you check first for potentially corrupt preference files?

~/Library/Preferences/ (Correct answer)
/Library/Application Support/
~/Library/Caches/
/System/Library/Frameworks/

Correct answer: ~/Library/Preferences/

Application preference files (.plist) stored in ~/Library/Preferences/ can become corrupt after system updates, causing app crashes. Removing or renaming the app's .plist file forces it to regenerate fresh preferences.

Each application stores its settings as a .plist (property list) file in ~/Library/Preferences/ named with the app's bundle identifier (e.g., com.apple.mail.plist). If an update changes the preference schema and the old file is incompatible, the app may crash. The fix is to move the suspect .plist file to the Desktop and relaunch the app. ~/Library/Caches/ is also worth clearing, but Preferences is the primary suspect for crash-at-launch issues.

Question 4: Which command-line tool can be used to unload a LaunchAgent or LaunchDaemon without restarting macOS?

launchctl (Correct answer)
pmset
defaults
diskutil

Correct answer: launchctl

launchctl is the command-line interface to launchd, macOS's init and service management daemon. It can load, unload, start, stop, and query the status of LaunchAgents and LaunchDaemons.

launchctl commands such as 'launchctl unload ~/Library/LaunchAgents/com.example.plist' and 'launchctl bootout' (macOS 10.11+) stop and unregister services. LaunchDaemons in /Library/LaunchDaemons/ run as root and start at boot, while LaunchAgents in /Library/LaunchAgents/ run per-user at login. Understanding both locations is essential for ACSP troubleshooting of startup items and background services.

Question 5: What does the macOS Gatekeeper feature check when a user opens a downloaded application?

Whether the app is signed with a valid Apple developer certificate and notarized (Correct answer)
Whether the app has passed the Mac App Store review process
Whether the app's bundle identifier is unique on the system
Whether the app was downloaded from an approved corporate server

Correct answer: Whether the app is signed with a valid Apple developer certificate and notarized

Gatekeeper verifies that downloaded applications are code-signed with a valid Apple Developer ID certificate and, for macOS 10.15+, have been notarized by Apple's automated security scanner.

Gatekeeper performs three checks: code signing (valid Developer ID certificate), notarization (Apple's automated malware scan approval), and optionally Mac App Store origin. If any check fails, macOS blocks the app launch and shows a warning. An administrator can override this for individual apps via System Settings > Privacy & Security or with 'spctl --add' in Terminal. Notarization was required starting with macOS 10.15 Catalina.

Question 6: Where are application bundles (.app files) stored for all users on a Mac versus only the current user?

/Applications/ for all users and ~/Applications/ for the current user only (Correct answer)
/System/Applications/ for all users and /Applications/ for the current user
/Library/Apps/ for all users and ~/Library/Apps/ for the current user
/usr/applications/ for all users and /home/apps/ for the current user

Correct answer: /Applications/ for all users and ~/Applications/ for the current user only

Applications in /Applications/ are available to all users on the Mac. Applications installed in ~/Applications/ (the user's home folder Applications directory) are only available to that specific user.

macOS uses /Applications/ as the system-wide application directory accessible to all users. Each user also has a ~/Applications/ folder for personal app installations. Some apps also install to /System/Applications/ (built-in Apple apps protected by SIP) and /System/Library/ (system components). When troubleshooting app availability for specific users, checking both locations is important. The Mac App Store installs apps to /Applications/ by default.

ACSP Apps and Processes 2

Which macOS tool lets you view all running processes and their CPU/memory usage in a graphical interface?