Ubuntu Unleashed 2019 Edition: Covering 18.04, 18.10, 19.04

The break   and exit    Statements

Using   Functions   in  Shell   Scripts

References

15 The Boot Process

Running Services    at  Boot

Beginning   the Boot    Loading Process

Loading the Linux   Kernel

System  Services    and Runlevels

Runlevel    Definitions

Booting into    the Default Runlevel

Understanding   init    Scripts and the Final   Stage   of  Initialization

Controlling Services    at  Boot    with    Administrative  Tools

Changing    Runlevels

Troubleshooting Runlevel    Problems

Starting    and Stopping    Services    Manually

Using   Upstart

Using   systemd

Boot-Repair

References

16 System-Monitoring Tools

Console-Based   Monitoring

Using   the kill    Command to  Control Processes

Using   Priority    Scheduling  and Control

Displaying  Free    and Used    Memory  with    free

Disk    Space

Disk    Quotas

Checking    Log Files

Rotating    Log Files

Graphical   Process-    and System-Management   Tools