Linux Bash Shell Scripting – A Practical way of Learning

Learning is important but most important is how to explore it. This course is designed in such a way that you can learn as well as explore the entire course module with various industrial projects.

Practical approach to learn and explore the shell scripting with various industrial projects

Course Content

Introduction of Shell Programming

• What is Bash Shell?
• Types of Shell available in Linux
• About Shell Scripting
• Bash Shell Startup Scripts
• User’s Home Directory – .bash_profile, .bashrc & .bash_logout
• Shebang
• Create a simple Shell Script
• Setting up permissions on a script
• Debug a Script

The Shell Variables & Environment

• Bash Variables
• Environmental Variables
• System Variables
• Assign values to shell variables
• Customize the bash shell environments
• set, env & export command
• Rules for naming variable name
• Simple Script using echo command
• Quoting
• There are three Type of quoting
• The double quote (“)
• The single quote (‘)
• The Backslash ()
• User’s Input via Keyboard
• Read Command
• IFS
• Practice Lab Session

Arithmetic Operations

• Performing Arithmetic Operations
• Create an integer Variable
• Create the Constants Variable
• Path name expansion
• Wildcards [*], ?, [..] etc
• Create & use aliases
• Practice Lab Sessions

Industrial Project to Completely Automate the Pre-validation report

• A Shell Script to collect required information from a server
• The Bash Color
• Writing Color Text
• Various Color Codes for Foreground & Background Text
• Lab Session on Bash Color
• Script to fetch the system information i.e system_details
• Schedule the script via cron
• Final Script to fetch the environment report on a single click
• Lab Session

Conditional Statements (Decision Making)

• Overview of conditional execution
• What is Condition?
• Boolean value (True & False)
• If else statement
• Lab Session on if..else..
• if..elif..else..fi statement
• test command
• Logical AND &&
• Logical OR !!
• The exit status of a command
• Numeric Comparison
• String Comparison
• File Attributes Comparison
• Shell Command line parameters
• Positional parameters via special shell variable $1, $2, $3,…,$N.
• Practice Lab Session

Bash Loops

• Overview of loop statement
• for loop statement
• Lab on for loop
• for loop using C like Syntax
• for loop using command line arguments
• Nested for loop statement
• Chessboard using nested loop statement
• While loop statement
• Lab Session – read a text file line-by-line or using IFS
• infinite while loop
• case statement
• Lab session on case statement
• Create a simple menu driven program or automation tool Using Case Statement
• Industrial Project
• Discussed various scripts using for or while loop

Shell Redirection & Process Management

• Input Output Redirection in Linux
• Lab Session on redirection
• Pipelines in Linux
• tee command
• file descriptor (fd) to file for output
• file descriptor (fd) to file for input
• file descriptor (fd) for reading & writing
• Practice Lab Session
• Overview of a Process
• Foreground & background Process
• Various Stats of a process
• Lab Session

Functions

• Defining functions
• Displaying functions
• Nested functions
• Lab Session – writing functions
• Calling functions
• Local & global variables
• Passing arguments into a function
• return statement
• Practice Lab Sessions

AWK

• Introduction Awk
• Pattern matching
• User defined variables in awk
• Awk pre-processing
• Awk post-processing
• Practice Lab Session

SED Stream Editor

• Introduction
• Replacing or substituting string.
• Replacing the nth occurrence of a pattern in a line
• Replacing all the occurrence of the pattern in a line
• Changing the slash (/) delimiter
• Using & as the matched string
• Duplicating the replaced line with /p flag
• Replacing string on a specific line number
• Replacing string on a range of lines
• Replace on a lines which matches a pattern
• Deleting lines
• Add a line after a match
• Add a line before a match
• Last Lecture