Linux Essentials

Linux Essentials

Detailed Course Outline

Introduction to the Linux Operating System

• Understand the evolution of the Linux OS and the various Linux Distributions
• Understand how to identify your Linux Distribution and OS release
• Linux standardization – an overview of standards in the Linux community
• Describe Linux shells (which shells are available, compare the common Linux shells, how to choose a shell)
• Describe the Linux kernel

Establishing Communication

• Log in and starting a shell session
• GUI desktop environments available to the Linux user
• Understanding the Linux command syntax
• Using emulation programs to access the system (ie. Putty / X-Windows / Telnet / SSH )
• Setting your terminal environment (stty)
• Executing commands from the command line; Linux Command syntax
• Using the Linux “help” facility: manual pages

Introduction to the Filing System

• Examining Linux files and directories
• Describe the Linux file system and directory structure
• Navigating the Linux directory hierarchy
• Understand the difference between full and relative paths
• Understanding the current and parent directories
• Understanding the differences between a Windows/DOS based filesystem and a Linux file system
• Differences between Windows (DOS) files and Linux files
• Describe mount points – mounting and unmounting filesystems
• Describe hard and symbolic links
• Describe home directories
• Disk space and checking the status of disks, filesystems, and directories (ie. du and df commands)

File Management

• Creating directories
• Copying files and directories
• Moving and renaming files and directories
• Removing files and directories
• Using shell metacharacters
• Locating files by name, owner, type and other parameters using the ‘find’ command

Linux Permissions

• Understanding permissions
• File permissions
• Directory permissions
• Change permissions with symbolic mode
• Change permissions with absolute (octal) mode
• Determine and set the umask value

Redirection Filters and Pipes

• Exploring standard input, standard output, and standard error
• Using filters
• Using pipes

Using the vi Editor

• Understand the Linux command line ASCII editors
• Understand the Vi modes
• Create/view/manipulate/save/delete files using the Vi editor
• Use a Vi initialization file

Introduction to shell scripts

• Creating simple shell scripts
• Choosing a Shell for your scripts
• The Bash Shell and Variables
• Understand the Pros and Cons of all the Linux shells
• Displaying the shell default variables
• Create/Remove user shell variables
• stty to set terminal types (backspace, etc.)

Introduction to the POSIX shell

• Shell initialization files (.profile, .bashrc)
• Understand set, export and env builtins for the bash shell
• Use bash shell variables
• Assign values to shell variables
• Display the value of shell variables
• Make variables available to subprocesses using the export statement
• Display the value of environment variables
• Unset shell and environment variables
• Customize the user environment using shell initialization files
• Perform arithmetic operations
• Create and use aliases
• Display aliases and the values assigned to them
• Display the built-in aliases
• Customize the bash shell environment
• Use the tilde expansion and command substitution features of the bash shell

Using Aliases and Functions

• Introducing the alias concept
• Using functions
• Making your aliases and functions permanent
• Removing aliases and functions

Command Editing and Command History

• Enabling command editing in the bash shell
• Using history to recall commands
• The command history file

System Status and Command Information

• Displaying system information and user status
• Determining command locations

Multitasking Capabilities

• Introduction to multitasking in the Linux environment
• Managing jobs and background processes
• Using the process table to manage processes
• Introducing delayed and detached jobs
• Display system processes
• Use processes and process identifiers (PIDs)
• Identify parent and child processes
• Terminate processes using the kill command

Advanced File Management

• Creating links
• Processing files with “awk”, “tr”, and “sed”
• Use awk/nawk commands from the command line
• Write awk programs to generate data reports from text files
• Write awk programs to generate numeric and text reports from text files

Command line data processing

• Using awk to display file contents and process data
• Formatting files with the tr command
• Using Linux filters to filter, sort and restructure data
• Use awk to scan text files or standard input to display specific data, change data format, and add text to existing data

Archiving User Data

• Managing file space
• Archiving files and directories
• Compressing files
• Use the tar utility to store files
• Backup files with the tar and compress commands
• Use compression tools to save storage space (zip, gzip, etc)

Printing

• Accessing printers and printing from the bash shell

Remote Connections

• Remotely access a system using telnet or ssh
• Transfer files with sftp and scp (using the command line)

Regular Expressions and the grep Command

• Use and describe regular expressions
• Describe the grep command
• Use the grep command to find patterns in a file
• Use the regular expression characters with the grep command
• Metacharacters
• The grep command

Stream Editing with ‘sed’

• Use sed to perform noninteractive editing tasks
• Substituting text
• Deleting and printing lines
• Reading and writing files
• Multiple ‘sed’ editor functions
• Use regular expression characters with sed 

Writing and Debugging Scripts

• Creating a shell script
• Put comments in a script
• Change permissions on a script
• Execute a script
• Debug a script

String Manipulation

• String Comparison
• String Relations
• Concatenation
• Substring Manipulations
• Wildcards and Pattern Matching

Conditionals

• Use the exit status of a command as conditional control
• Use the “if” statement to test a condition
• Pass values using command-line arguments (positional parameters) into a script
• Create USAGE messages
• Place parameters on the command line
• Use conditional if, then, elif, else, and fi constructs
• Use exit, let, and test statements ([[ ]], ” “)
• Apply the &&, ||, and ! Boolean logic operators
• Use the case statement

Interactive Scripts

• Use the print and echo commands to display text
• Use the read command to interactively assign data to a shell variable
• Read user input into one or more variables, using one read statement
• Use special characters, with print and echo, to make the displayed text more user friendly
• Create a “here” document
• Use file descriptors to read from and write to multiple files

Loops

• Write scripts that use for, while, and until loops
• Write a script using the select statement
• Describe when to use loops within a script
• Generate argument lists using command, variable, and file-name substitution

Advanced Variables, Parameters, and Argument Lists

• Declare strings, integers, and array variables
• Manipulate string variables
• Change the values of the positional parameters using the set statement within a script
• Pass values using command-line arguments (positional parameters) into a script
• Declare string and array variables
• Setting and retrieving arrays
• Set default values for parameters
• Use the shell built-in let, print, set, and typeset statements
• Reading user input
• Positional parameters
• Creating positional parameters
• Conditional substitution
• Working with arithmetic operators and data

Functions

• Create user-defined functions in a shell script
• Create, invoke, and display functions from the command line
• Pass arguments into a function
• Call functions from special (function) files that are saved in one or more function directories
• Describe where functions are available for use

Controlling Script Behavior

• Manage the use of temporary files
• Write scripts using the setuid bit
• Use the crontab command

Scheduling Execution

• Sleep
• Date
• Cron and crontab

Traps

• Describe how the trap statement works
• Include trap statements in a script
• Use the trap statement to catch signals and handle errors