Library Look up only what you need, then get back to the task.

Library

A fast lookup surface for cross-platform command recall, with cleaner scanning and direct links back into lessons and labs.

Reference

855+ commands, searchable without the clutter.

Use the library when you need a crisp reminder, then jump straight into the modules and labs that turn recall into real operating-system fluency.

855+ entries Cross-platform lookup Fast return to study Lesson and lab guidance Task and playbook guidance
Use it well

Lookup should shorten the gap back to learning.

Use the Library for a crisp reminder, not as a substitute for the lesson that explains the idea or the lab that proves you can use it.

Best sequence

Lookup the command, open the matching lesson if the concept is unclear, then run the matching lab if the command is known but the workflow is still shaky.

Need one domain fast?

Open Topics when you need a tighter permissions, networking, process, storage, or scripting entry point instead of broad search first.

Need one job done?

Use Task Guides for normal workflows and Troubleshooting Playbooks when the command is part of fixing a symptom, not just remembering syntax.

Search
855 matching commandsfrom 855 total855 with lesson or lab guidance
System Power & Boot

View boot messages

Linuxdmesg, journalctl -b
WindowsGet-WinEvent -LogName System

Shows kernel boot logs

BeginnerLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M46 - Logging & Event AnalysisField-verifiedDirect command coverage in the curriculum.M47 - Services ManagementDirect command coverage in the curriculum.
Practice it
LAB-HW-02 - Kernel Rings & dmesgHands-on practice that uses this command directly.LAB-MON-02 - The Journalctl VaultHands-on practice that uses this command directly.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Mount an External Drive SafelyUse this to complete the real task safely.
Troubleshoot it
A Service Will Not StartUse this when the command is part of troubleshooting, not just normal operation.
HardwareConfiguration
Practice this category
System Power & Boot

Check boot time

Linuxsystemd-analyze
WindowsGet-CimInstance Win32_OperatingSystem

System startup duration

BeginnerLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M48 - Boot & StartupDirect command coverage in the curriculum.M01 - What Is an Operating System?Field-verifiedBest-fit module for this command family and topic.
Practice it
LAB-HW-02 - Kernel Rings & dmesgPractice this command family in a real terminal flow.LAB-HW-01 - Exploring System HardwarePractice this command family in a real terminal flow.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Mount an External Drive SafelyUse this to complete the real task safely.
Troubleshoot it
The System Feels SlowUse this when the command is part of troubleshooting, not just normal operation.
HardwareConfiguration
Practice this category
System Power & Boot

View BIOS/UEFI settings

Linuxdmidecode, efibootmgr
WindowsGet-ComputerInfo, bcdedit

Firmware configuration

BeginnerLinuxWindowsHas lessonHas labHas task guide
Learn deeply
M00 - Your Environment - The Workshop Before the WorkField-verifiedDirect command coverage in the curriculum.M48 - Boot & StartupBest-fit module for this command family and topic.
Practice it
LAB-HW-02 - Kernel Rings & dmesgPractice this command family in a real terminal flow.LAB-HW-01 - Exploring System HardwarePractice this command family in a real terminal flow.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Mount an External Drive SafelyUse this to complete the real task safely.
HardwareConfiguration
Practice this category
System Power & Boot

List boot entries

Linuxefibootmgr -v
Windowsbcdedit /enum

Available boot options

BeginnerLinuxWindowsHas lessonHas labHas task guide
Learn deeply
M48 - Boot & StartupBest-fit module for this command family and topic.M01 - What Is an Operating System?Field-verifiedBest-fit module for this command family and topic.
Practice it
LAB-HW-02 - Kernel Rings & dmesgPractice this command family in a real terminal flow.LAB-HW-01 - Exploring System HardwarePractice this command family in a real terminal flow.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Mount an External Drive SafelyUse this to complete the real task safely.
HardwareConfiguration
Practice this category
System Power & Boot

Set default boot entry

Linuxefibootmgr -o XXXX
Windowsbcdedit /default {id}

Choose startup OS (`-o` = boot order)

BeginnerLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M48 - Boot & StartupBest-fit module for this command family and topic.M01 - What Is an Operating System?Field-verifiedBest-fit module for this command family and topic.
Practice it
LAB-HW-02 - Kernel Rings & dmesgPractice this command family in a real terminal flow.LAB-HW-01 - Exploring System HardwarePractice this command family in a real terminal flow.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Mount an External Drive SafelyUse this to complete the real task safely.
Troubleshoot it
The System Feels SlowUse this when the command is part of troubleshooting, not just normal operation.
HardwareConfiguration
Practice this category
System Startup & Services

List all services

Linuxsystemctl list-units --type=service
WindowsGet-Service

Shows service status

IntermediateLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M47 - Services ManagementDirect command coverage in the curriculum.M53 - Troubleshooting Lab: 5 Break ScenariosDirect command coverage in the curriculum.
Practice it
LAB-HW-03 - Systemd Service ArchitectureHands-on practice that uses this command directly.LAB-PROC-05 - Service Persistence: systemdHands-on practice that uses this command directly.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Inspect Open Ports and Listening ServicesUse this to complete the real task safely.
Troubleshoot it
A Service Will Not StartUse this when the command is part of troubleshooting, not just normal operation.The System Feels SlowUse this when the command is part of troubleshooting, not just normal operation.
ConfigurationAutomation
Practice this category
System Startup & Services

Start a service

Linuxsystemctl start SERVICE
WindowsStart-Service NAME

Activate service

IntermediateLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M47 - Services ManagementDirect command coverage in the curriculum.M48 - Boot & StartupDirect command coverage in the curriculum.
Practice it
LAB-HW-03 - Systemd Service ArchitectureHands-on practice that uses this command directly.LAB-PROC-05 - Service Persistence: systemdHands-on practice that uses this command directly.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Inspect Open Ports and Listening ServicesUse this to complete the real task safely.
Troubleshoot it
DNS Works by IP but Not by NameField-verifiedUse this when the command is part of troubleshooting, not just normal operation.A Service Will Not StartUse this when the command is part of troubleshooting, not just normal operation.
ConfigurationAutomation
Practice this category
System Startup & Services

Stop a service

Linuxsystemctl stop SERVICE
WindowsStop-Service NAME

Deactivate service

IntermediateLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M47 - Services ManagementDirect command coverage in the curriculum.M48 - Boot & StartupDirect command coverage in the curriculum.
Practice it
LAB-HW-03 - Systemd Service ArchitectureHands-on practice that uses this command directly.LAB-PROC-05 - Service Persistence: systemdHands-on practice that uses this command directly.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Inspect Open Ports and Listening ServicesUse this to complete the real task safely.
Troubleshoot it
DNS Works by IP but Not by NameField-verifiedUse this when the command is part of troubleshooting, not just normal operation.A Service Will Not StartUse this when the command is part of troubleshooting, not just normal operation.
ConfigurationAutomation
Practice this category
System Startup & Services

Enable service at boot

Linuxsystemctl enable SERVICE
WindowsSet-Service -StartupType Automatic

Auto-start configuration

IntermediateLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M47 - Services ManagementDirect command coverage in the curriculum.M48 - Boot & StartupDirect command coverage in the curriculum.
Practice it
LAB-HW-03 - Systemd Service ArchitectureHands-on practice that uses this command directly.LAB-PROC-05 - Service Persistence: systemdHands-on practice that uses this command directly.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Inspect Open Ports and Listening ServicesUse this to complete the real task safely.
Troubleshoot it
A Service Will Not StartUse this when the command is part of troubleshooting, not just normal operation.The System Feels SlowUse this when the command is part of troubleshooting, not just normal operation.
ConfigurationAutomation
Practice this category
System Startup & Services

Disable service at boot

Linuxsystemctl disable SERVICE
WindowsSet-Service -StartupType Disabled

Prevent auto-start

IntermediateLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M47 - Services ManagementDirect command coverage in the curriculum.M48 - Boot & StartupDirect command coverage in the curriculum.
Practice it
LAB-HW-03 - Systemd Service ArchitectureHands-on practice that uses this command directly.LAB-PROC-05 - Service Persistence: systemdHands-on practice that uses this command directly.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Inspect Open Ports and Listening ServicesUse this to complete the real task safely.
Troubleshoot it
A Service Will Not StartUse this when the command is part of troubleshooting, not just normal operation.The System Feels SlowUse this when the command is part of troubleshooting, not just normal operation.
ConfigurationAutomation
Practice this category
System Startup & Services

Check service status

Linuxsystemctl status SERVICE
WindowsGet-Service NAME \

Format-List`

IntermediateLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M47 - Services ManagementDirect command coverage in the curriculum.M53 - Troubleshooting Lab: 5 Break ScenariosDirect command coverage in the curriculum.
Practice it
LAB-HW-03 - Systemd Service ArchitectureHands-on practice that uses this command directly.LAB-PROC-05 - Service Persistence: systemdHands-on practice that uses this command directly.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Inspect Open Ports and Listening ServicesUse this to complete the real task safely.
Troubleshoot it
DNS Works by IP but Not by NameField-verifiedUse this when the command is part of troubleshooting, not just normal operation.A Service Will Not StartUse this when the command is part of troubleshooting, not just normal operation.
ConfigurationAutomation
Practice this category
System Startup & Services

Restart a service

Linuxsystemctl restart SERVICE
WindowsRestart-Service NAME

Stop and start

IntermediateLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M47 - Services ManagementDirect command coverage in the curriculum.M48 - Boot & StartupDirect command coverage in the curriculum.
Practice it
LAB-HW-03 - Systemd Service ArchitectureHands-on practice that uses this command directly.LAB-PROC-05 - Service Persistence: systemdHands-on practice that uses this command directly.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Inspect Open Ports and Listening ServicesUse this to complete the real task safely.
Troubleshoot it
DNS Works by IP but Not by NameField-verifiedUse this when the command is part of troubleshooting, not just normal operation.A Service Will Not StartUse this when the command is part of troubleshooting, not just normal operation.
ConfigurationAutomation
Practice this category
System Startup & Services

View service dependencies

Linuxsystemctl list-dependencies SERVICE
WindowsGet-Service -DependentServices

Service relationships

IntermediateLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M47 - Services ManagementDirect command coverage in the curriculum.M53 - Troubleshooting Lab: 5 Break ScenariosDirect command coverage in the curriculum.
Practice it
LAB-HW-03 - Systemd Service ArchitectureHands-on practice that uses this command directly.LAB-PROC-05 - Service Persistence: systemdHands-on practice that uses this command directly.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Inspect Open Ports and Listening ServicesUse this to complete the real task safely.
Troubleshoot it
A Service Will Not StartUse this when the command is part of troubleshooting, not just normal operation.The System Feels SlowUse this when the command is part of troubleshooting, not just normal operation.
ConfigurationAutomation
Practice this category
System Shutdown & Reboot

Shutdown immediately

Linuxshutdown -h now, poweroff
WindowsStop-Computer -Force

Immediate power off

BeginnerLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M43 - Task AutomationBest-fit module for this command family and topic.M49 - System Updates & PatchingBest-fit module for this command family and topic.
Practice it
LAB-AUTO-01 - Cron & SchedulingField-verifiedPractice this command family in a real terminal flow.LAB-HW-02 - Kernel Rings & dmesgPractice this command family in a real terminal flow.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Change File Permissions CorrectlyField-verifiedUse this to complete the real task safely.
Troubleshoot it
Access Denied on a File or FolderField-verifiedUse this when the command is part of troubleshooting, not just normal operation.A Service Will Not StartUse this when the command is part of troubleshooting, not just normal operation.
AccessAutomation
Practice this category
System Shutdown & Reboot

Shutdown with delay

Linuxshutdown -h +10
Windowsshutdown /s /t 600

Scheduled shutdown (in seconds)

BeginnerLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M43 - Task AutomationBest-fit module for this command family and topic.M49 - System Updates & PatchingBest-fit module for this command family and topic.
Practice it
LAB-AUTO-01 - Cron & SchedulingField-verifiedPractice this command family in a real terminal flow.LAB-PERM-03 - Numeric Permissions (Octal)Practice this command family in a real terminal flow.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Change File Permissions CorrectlyField-verifiedUse this to complete the real task safely.
Troubleshoot it
Access Denied on a File or FolderField-verifiedUse this when the command is part of troubleshooting, not just normal operation.
AccessAutomation
Practice this category
System Shutdown & Reboot

Reboot system

Linuxreboot, shutdown -r now
WindowsRestart-Computer -Force

System restart

BeginnerLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M49 - System Updates & PatchingDirect command coverage in the curriculum.M43 - Task AutomationBest-fit module for this command family and topic.
Practice it
LAB-AUTO-01 - Cron & SchedulingField-verifiedPractice this command family in a real terminal flow.LAB-HW-02 - Kernel Rings & dmesgPractice this command family in a real terminal flow.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Change File Permissions CorrectlyField-verifiedUse this to complete the real task safely.
Troubleshoot it
Access Denied on a File or FolderField-verifiedUse this when the command is part of troubleshooting, not just normal operation.A Service Will Not StartUse this when the command is part of troubleshooting, not just normal operation.
AccessAutomation
Practice this category
System Shutdown & Reboot

Cancel scheduled shutdown

Linuxshutdown -c
Windowsshutdown /a

Abort pending shutdown

BeginnerLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M43 - Task AutomationBest-fit module for this command family and topic.M49 - System Updates & PatchingBest-fit module for this command family and topic.
Practice it
LAB-AUTO-01 - Cron & SchedulingField-verifiedPractice this command family in a real terminal flow.LAB-HW-02 - Kernel Rings & dmesgPractice this command family in a real terminal flow.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Change File Permissions CorrectlyField-verifiedUse this to complete the real task safely.
Troubleshoot it
Access Denied on a File or FolderField-verifiedUse this when the command is part of troubleshooting, not just normal operation.
AccessAutomation
Practice this category
System Shutdown & Reboot

Hibernate

Linuxsystemctl hibernate
Windowsshutdown /h

Save to disk, power off

BeginnerLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M47 - Services ManagementDirect command coverage in the curriculum.M43 - Task AutomationDirect command coverage in the curriculum.
Practice it
LAB-HW-03 - Systemd Service ArchitectureHands-on practice that uses this command directly.LAB-PROC-05 - Service Persistence: systemdHands-on practice that uses this command directly.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Change File Permissions CorrectlyField-verifiedUse this to complete the real task safely.
Troubleshoot it
Access Denied on a File or FolderField-verifiedUse this when the command is part of troubleshooting, not just normal operation.A Service Will Not StartUse this when the command is part of troubleshooting, not just normal operation.
AccessAutomation
Practice this category
System Shutdown & Reboot

Suspend/Sleep

Linuxsystemctl suspend
Windowsrundll32.exe powrprof.dll,SetSuspendState 0,1,0

Low power mode

BeginnerLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M47 - Services ManagementDirect command coverage in the curriculum.M43 - Task AutomationDirect command coverage in the curriculum.
Practice it
LAB-HW-03 - Systemd Service ArchitectureHands-on practice that uses this command directly.LAB-PROC-05 - Service Persistence: systemdHands-on practice that uses this command directly.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Change File Permissions CorrectlyField-verifiedUse this to complete the real task safely.
Troubleshoot it
Access Denied on a File or FolderField-verifiedUse this when the command is part of troubleshooting, not just normal operation.A Service Will Not StartUse this when the command is part of troubleshooting, not just normal operation.
AccessAutomation
Practice this category
Runlevels & Targets

View current target

Linuxsystemctl get-default

System run mode

AdvancedLinuxHas lessonHas labHas task guideHas playbook
Learn deeply
M47 - Services ManagementDirect command coverage in the curriculum.M48 - Boot & StartupDirect command coverage in the curriculum.
Practice it
LAB-HW-03 - Systemd Service ArchitectureHands-on practice that uses this command directly.LAB-PROC-05 - Service Persistence: systemdHands-on practice that uses this command directly.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Change File Permissions CorrectlyField-verifiedUse this to complete the real task safely.
Troubleshoot it
A Service Will Not StartUse this when the command is part of troubleshooting, not just normal operation.
ConfigurationExpert
Practice this category
Runlevels & Targets

Change to multi-user

Linuxsystemctl isolate multi-user.target

CLI mode

AdvancedLinuxHas lessonHas labHas task guideHas playbook
Learn deeply
M47 - Services ManagementDirect command coverage in the curriculum.M48 - Boot & StartupDirect command coverage in the curriculum.
Practice it
LAB-HW-03 - Systemd Service ArchitectureHands-on practice that uses this command directly.LAB-PROC-05 - Service Persistence: systemdHands-on practice that uses this command directly.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Mount an External Drive SafelyUse this to complete the real task safely.
Troubleshoot it
A Service Will Not StartUse this when the command is part of troubleshooting, not just normal operation.
ConfigurationExpert
Practice this category
Runlevels & Targets

Change to graphical

Linuxsystemctl isolate graphical.target

GUI mode

AdvancedLinuxHas lessonHas labHas task guideHas playbook
Learn deeply
M47 - Services ManagementDirect command coverage in the curriculum.M48 - Boot & StartupDirect command coverage in the curriculum.
Practice it
LAB-HW-03 - Systemd Service ArchitectureHands-on practice that uses this command directly.LAB-PROC-05 - Service Persistence: systemdHands-on practice that uses this command directly.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Mount an External Drive SafelyUse this to complete the real task safely.
Troubleshoot it
A Service Will Not StartUse this when the command is part of troubleshooting, not just normal operation.
ConfigurationExpert
Practice this category
Runlevels & Targets

Set default target

Linuxsystemctl set-default graphical.target

Persistent boot mode

AdvancedLinuxHas lessonHas labHas task guideHas playbook
Learn deeply
M47 - Services ManagementDirect command coverage in the curriculum.M48 - Boot & StartupDirect command coverage in the curriculum.
Practice it
LAB-HW-03 - Systemd Service ArchitectureHands-on practice that uses this command directly.LAB-PROC-05 - Service Persistence: systemdHands-on practice that uses this command directly.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Mount an External Drive SafelyUse this to complete the real task safely.
Troubleshoot it
A Service Will Not StartUse this when the command is part of troubleshooting, not just normal operation.
ConfigurationExpert
Practice this category
Runlevels & Targets

Enter rescue mode

Linuxsystemctl rescue
Windowsbcdedit /set {default} safeboot minimal

Minimal system

AdvancedLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M47 - Services ManagementDirect command coverage in the curriculum.M48 - Boot & StartupDirect command coverage in the curriculum.
Practice it
LAB-HW-03 - Systemd Service ArchitectureHands-on practice that uses this command directly.LAB-PROC-05 - Service Persistence: systemdHands-on practice that uses this command directly.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Mount an External Drive SafelyUse this to complete the real task safely.
Troubleshoot it
Access Denied on a File or FolderField-verifiedUse this when the command is part of troubleshooting, not just normal operation.A Service Will Not StartUse this when the command is part of troubleshooting, not just normal operation.
ConfigurationExpert
Practice this category
Runlevels & Targets

Enter emergency mode

Linuxsystemctl emergency

Bare minimal

AdvancedLinuxHas lessonHas labHas task guideHas playbook
Learn deeply
M47 - Services ManagementDirect command coverage in the curriculum.M48 - Boot & StartupDirect command coverage in the curriculum.
Practice it
LAB-HW-03 - Systemd Service ArchitectureHands-on practice that uses this command directly.LAB-PROC-05 - Service Persistence: systemdHands-on practice that uses this command directly.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Mount an External Drive SafelyUse this to complete the real task safely.
Troubleshoot it
Access Denied on a File or FolderField-verifiedUse this when the command is part of troubleshooting, not just normal operation.A Service Will Not StartUse this when the command is part of troubleshooting, not just normal operation.
ConfigurationExpert
Practice this category
GRUB & Bootloader Configuration

View GRUB config

Linuxcat /etc/default/grub

Boot parameters

AdvancedLinuxHas lessonHas labHas task guide
Learn deeply
M07 - File Operations: View and ReadField-verifiedDirect command coverage in the curriculum.M49 - System Updates & PatchingDirect command coverage in the curriculum.
Practice it
LAB-SEC-03 - SSH Key AuthenticationField-verifiedHands-on practice that uses this command directly.LAB-FS-02 - Inside /etc - The Config VaultField-verifiedCovers the same workflow in guided practice.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Mount an External Drive SafelyUse this to complete the real task safely.
ConfigurationLinux
Practice this category
GRUB & Bootloader Configuration

Update GRUB after changes

Linuxupdate-grub or grub-mkconfig -o /boot/grub/grub.cfg

Regenerate boot menu

AdvancedLinuxHas lessonHas labHas task guide
Learn deeply
M48 - Boot & StartupBest-fit module for this command family and topic.M49 - System Updates & PatchingBest-fit module for this command family and topic.
Practice it
LAB-HW-01 - Exploring System HardwarePractice this command family in a real terminal flow.LAB-HW-02 - Kernel Rings & dmesgPractice this command family in a real terminal flow.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Mount an External Drive SafelyUse this to complete the real task safely.
ConfigurationLinux
Practice this category
GRUB & Bootloader Configuration

Install GRUB to disk

Linuxgrub-install /dev/sda

Write bootloader

AdvancedLinuxHas lessonHas labHas task guideHas playbook
Learn deeply
M48 - Boot & StartupBest-fit module for this command family and topic.M24 - Storage ArchitectureField-verifiedBest-fit module for this command family and topic.
Practice it
LAB-FS-05 - Device Files & MountingPractice this command family in a real terminal flow.LAB-PKG-01 - Apt & Debian Package ManagementField-verifiedPractice this command family in a real terminal flow.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Mount an External Drive SafelyUse this to complete the real task safely.
Troubleshoot it
The System Feels SlowUse this when the command is part of troubleshooting, not just normal operation.
ConfigurationLinux
Practice this category
GRUB & Bootloader Configuration

Set default boot entry

Linuxgrub-set-default 0
Windowsbcdedit /default {id}

Choose default OS

AdvancedLinuxWindowsHas lessonHas labHas task guide
Learn deeply
M48 - Boot & StartupBest-fit module for this command family and topic.M49 - System Updates & PatchingBest-fit module for this command family and topic.
Practice it
LAB-HW-01 - Exploring System HardwarePractice this command family in a real terminal flow.LAB-HW-02 - Kernel Rings & dmesgPractice this command family in a real terminal flow.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Mount an External Drive SafelyUse this to complete the real task safely.
ConfigurationLinux
Practice this category
GRUB & Bootloader Configuration

Add kernel parameters

LinuxEdit GRUB_CMDLINE_LINUX in /etc/default/grub
Windowsbcdedit /set {default} option value

Boot-time options

AdvancedLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M48 - Boot & StartupBest-fit module for this command family and topic.M49 - System Updates & PatchingBest-fit module for this command family and topic.
Practice it
LAB-HW-02 - Kernel Rings & dmesgPractice this command family in a real terminal flow.LAB-HW-01 - Exploring System HardwarePractice this command family in a real terminal flow.
Do the task
Create a User Account SafelyUse this to complete the real task safely.Check What Is Using MemoryUse this to complete the real task safely.
Troubleshoot it
Access Denied on a File or FolderField-verifiedUse this when the command is part of troubleshooting, not just normal operation.
ConfigurationLinux
Practice this category
GRUB & Bootloader Configuration

View boot time analysis

Linuxsystemd-analyze

Total boot duration

AdvancedLinuxHas lessonHas labHas task guide
Learn deeply
M48 - Boot & StartupDirect command coverage in the curriculum.M46 - Logging & Event AnalysisField-verifiedBest-fit module for this command family and topic.
Practice it
LAB-HW-01 - Exploring System HardwarePractice this command family in a real terminal flow.LAB-HW-02 - Kernel Rings & dmesgPractice this command family in a real terminal flow.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Mount an External Drive SafelyUse this to complete the real task safely.
ConfigurationLinux
Practice this category
GRUB & Bootloader Configuration

Blame slow services

Linuxsystemd-analyze blame

Slowest services at boot

AdvancedLinuxHas lessonHas labHas task guide
Learn deeply
M48 - Boot & StartupDirect command coverage in the curriculum.M47 - Services ManagementBest-fit module for this command family and topic.
Practice it
LAB-HW-03 - Systemd Service ArchitecturePractice this command family in a real terminal flow.LAB-HW-01 - Exploring System HardwarePractice this command family in a real terminal flow.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Mount an External Drive SafelyUse this to complete the real task safely.
ConfigurationLinux
Practice this category
GRUB & Bootloader Configuration

Boot dependency chain

Linuxsystemd-analyze critical-chain

Critical path visualization

AdvancedLinuxHas lessonHas labHas task guide
Learn deeply
M48 - Boot & StartupDirect command coverage in the curriculum.M04 - File System Architecture: How Your OS Organises DataField-verifiedBest-fit module for this command family and topic.
Practice it
LAB-HW-02 - Kernel Rings & dmesgPractice this command family in a real terminal flow.LAB-NAV-01 - First Steps: pwd, ls, cdField-verifiedPractice this command family in a real terminal flow.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Change File Permissions CorrectlyField-verifiedUse this to complete the real task safely.
ConfigurationLinux
Practice this category
GRUB & Bootloader Configuration

Repair Windows bootloader

Windowsbootrec /fixmbr, bootrec /fixboot, bootrec /rebuildbcd

Fix BCD store

AdvancedWindowsHas lessonHas labHas task guide
Learn deeply
M48 - Boot & StartupBest-fit module for this command family and topic.M49 - System Updates & PatchingBest-fit module for this command family and topic.
Practice it
LAB-HW-01 - Exploring System HardwarePractice this command family in a real terminal flow.LAB-HW-02 - Kernel Rings & dmesgPractice this command family in a real terminal flow.
Do the task
Check What Is Using MemoryUse this to complete the real task safely.Change File Permissions CorrectlyField-verifiedUse this to complete the real task safely.
ConfigurationLinux
Practice this category
Session Management

Login to system

Linuxlogin
WindowsGUI or runas

Establish user session

BeginnerLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M13 - Users and Groups: GUIDirect command coverage in the curriculum.M05 - Navigation: GUI FirstField-verifiedDirect command coverage in the curriculum.
Practice it
LAB-USER-06 - Switching Identities: su vs su -Hands-on practice that uses this command directly.LAB-SEC-03 - SSH Key AuthenticationField-verifiedHands-on practice that uses this command directly.
Do the task
Create a User Account SafelyUse this to complete the real task safely.Check What Is Using MemoryUse this to complete the real task safely.
Troubleshoot it
Access Denied on a File or FolderField-verifiedUse this when the command is part of troubleshooting, not just normal operation.
AccessMonitoring
Practice this category
Session Management

Logout current session

Linuxexit, logout
Windowslogoff

End session

BeginnerLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M00 - Your Environment - The Workshop Before the WorkField-verifiedBest-fit module for this command family and topic.M12 - Who Owns What: Users and GroupsField-verifiedBest-fit module for this command family and topic.
Practice it
LAB-USER-02 - Creating and Modifying UsersPractice this command family in a real terminal flow.LAB-USER-04 - Group Dynamics & File ModesPractice this command family in a real terminal flow.
Do the task
Create a User Account SafelyUse this to complete the real task safely.Change File Permissions CorrectlyField-verifiedUse this to complete the real task safely.
Troubleshoot it
Access Denied on a File or FolderField-verifiedUse this when the command is part of troubleshooting, not just normal operation.
AccessMonitoring
Practice this category
Session Management

Current user name

Linuxwhoami
Windowswhoami, $env:USERNAME

Who am I logged in as?

BeginnerLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M14 - Users and Groups: CLIDirect command coverage in the curriculum.M00 - Your Environment - The Workshop Before the WorkField-verifiedDirect command coverage in the curriculum.
Practice it
LAB-USER-01 - Understanding Users & IdentityPractice this command family in a real terminal flow.LAB-USER-02 - Creating and Modifying UsersPractice this command family in a real terminal flow.
Do the task
Create a User Account SafelyUse this to complete the real task safely.Change File Permissions CorrectlyField-verifiedUse this to complete the real task safely.
Troubleshoot it
Access Denied on a File or FolderField-verifiedUse this when the command is part of troubleshooting, not just normal operation.DNS Works by IP but Not by NameField-verifiedUse this when the command is part of troubleshooting, not just normal operation.
AccessMonitoring
Practice this category
Session Management

Switch user

Linuxsu - username
Windowsrunas /user:DOMAIN\user

Change active user

BeginnerLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M16 - Elevation: UAC and sudoDirect command coverage in the curriculum.M13 - Users and Groups: GUIDirect command coverage in the curriculum.
Practice it
LAB-USER-06 - Switching Identities: su vs su -Hands-on practice that uses this command directly.LAB-USER-04 - Group Dynamics & File ModesHands-on practice that uses this command directly.
Do the task
Create a User Account SafelyUse this to complete the real task safely.Change File Permissions CorrectlyField-verifiedUse this to complete the real task safely.
Troubleshoot it
Access Denied on a File or FolderField-verifiedUse this when the command is part of troubleshooting, not just normal operation.
AccessMonitoring
Practice this category
Session Management

List logged-in users

Linuxwho, w
Windowsquser, query user

Active sessions

BeginnerLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M12 - Who Owns What: Users and GroupsField-verifiedDirect command coverage in the curriculum.M13 - Users and Groups: GUIDirect command coverage in the curriculum.
Practice it
LAB-MON-02 - The Journalctl VaultHands-on practice that uses this command directly.LAB-USER-02 - Creating and Modifying UsersHands-on practice that uses this command directly.
Do the task
Create a User Account SafelyUse this to complete the real task safely.Change File Permissions CorrectlyField-verifiedUse this to complete the real task safely.
Troubleshoot it
Access Denied on a File or FolderField-verifiedUse this when the command is part of troubleshooting, not just normal operation.
AccessMonitoring
Practice this category
Session Management

Show login history

Linuxlast
WindowsGet-WinEvent -FilterHashtable @{LogName='Security';Id=4624}

Past logins

BeginnerLinuxWindowsHas lessonHas labHas task guideHas playbook
Learn deeply
M46 - Logging & Event AnalysisField-verifiedDirect command coverage in the curriculum.M00 - Your Environment - The Workshop Before the WorkField-verifiedBest-fit module for this command family and topic.
Practice it
LAB-SEC-01 - The UFW FirewallPractice this command family in a real terminal flow.LAB-SEC-03 - SSH Key AuthenticationField-verifiedPractice this command family in a real terminal flow.
Do the task
Create a User Account SafelyUse this to complete the real task safely.Change File Permissions CorrectlyField-verifiedUse this to complete the real task safely.
Troubleshoot it
Access Denied on a File or FolderField-verifiedUse this when the command is part of troubleshooting, not just normal operation.A Service Will Not StartUse this when the command is part of troubleshooting, not just normal operation.
AccessMonitoring
Practice this category