Shell Scripting UNIX/Linux Training Course

Introduction

• Objectives
• Course Schedule
• Course Introductions
• Pre-requisites
• Bibliography
• Delegate Responsibilities
• Course Summary

Review of Basics - Optional

• Files
• Directories and Processes
• Displaying Directories - ls
• Getting Help - man
• Displaying Files - cat, more
• Simple Commands
• Piping - using | symbol
• Redirection - using > symbol
• Appending to a File - using >> symbol
• Redirecting Input - using < symbol
• Redirecting Errors
• Using /dev/null for Error Handling
• Foreground Jobs
• Background Jobs - &
• Stopping Jobs - kill
• Special Files - . and ..
• The Command Prompt - PS1
• Creating Aliases
• Using Aliases
• Command History
• Command Line Editing - using Arrow Keys
• Command Line Editing - using vi
• Customizing the Shell for government operations
• The Home Directory - HOME
• The Working Directory - pwd
• Changing Directories - cd
• Creating Directories - mkdir
• Removing Directories - rmdir
• Interactive Copy - cp -i
• Interactive Move - mv -i
• Interactive Remove - rm -i
• Recursively Removing Directories - rm -r
• Wild Cards for File Name Generation
• Word Count - wc
• Finding Files - find
• Finding Text in Files - grep, sort, cut, uniq, tr
• Changing Permissions - chmod

Shell Programming

• Creating Shell Scripts for government tasks
• Testing the Command
• Creating the Script File
• Adding Execute Permissions
• Testing the Script
• Running the Script - time
• Running the Script - dot
• Running the Script - exec
• Running the Script - ksh
• Debugging the Script for government use
• Passing Parameters to Scripts
• The read Command
• Using read in Scripts for user input
• Choosing the Shell for government operations
• Tidying the Output of Scripts
• Suppressing Input - stty

Special Characters and Variables

• Quotation Marks for String Handling
• Quoted Strings - ", '
• Escape Character - *
• Quoted Strings - `
• Using $(...) for Command Substitution
• System Variables - set
• Other Special Variables for government use
• User Variables for customization
• User Variables - unset
• Variables in Scripts for dynamic content
• Typeset Command for variable types
• Integer Variables for calculations
• Special Constructs for advanced scripting

Creating Menus

• Conditions - case for decision-making
• Creating a Menu for user interaction
• Iteration - while, until for looping
• Holding the Output - sleep for timing control
• Holding the Output - dummy read for input handling
• Ending the Script gracefully
• Ending the Loop conditionally
• Hidden Option - forking a shell for background processes
• Trapping Interrupts - trap for error handling
• More on Interrupts for robust scripts
• Highlighting Text - tput for visual feedback
• Positioning the Cursor - backtab \b for precise control
• Korn Shell Menu for enhanced user experience

Selection

• Conditional Testing for logical operations
• Testing File Attributes for file management
• Testing File Permissions for security checks
• Multiple Tests - Nested ifs for complex conditions
• Multiple Tests - elseif for streamlined logic
• The NOT Condition for negation
• Multiple Conditions in One Test for efficient evaluation
• Testing Strings for data validation
• Using Square Brackets for conditional expressions
• Avoiding Null Input for robust scripts
• Testing Numbers for numerical operations
• More on case for advanced pattern matching
• Displaying Variables for transparency
• Placing Spaces for readability
• Testing Commands for execution verification

Iteration, Looping

• Computations - let for arithmetic operations
• Iteration - while, until for repetitive tasks
• Infinite Loop for continuous processes
• Iteration - for for iterating over elements
• More than 9 Parameters - shift for handling large inputs

Sub-scripts and Functions

• Local and Global Variables for scope management
• Sub-scripts for modular coding
• Export Command for variable sharing
• Exit Status for error handling
• Aliases for command shortcuts
• Functions for reusable code blocks
• Useful Functions for common tasks
• Return Status for function results
• Manipulating Functions for dynamic behavior
• Functions in Scripts for enhanced functionality

Advanced Commands

• Debugging - set for script diagnostics
• Setting - set for configuration options
• Merging Files - join for data integration
• Merging Files - paste, basename and dirname for file manipulation
• Job Control - jobs for managing processes
• Regular Expressions for pattern matching
• Global Regular Expression Printer - grep for text search
• Extended Regular Expression grep - egrep for advanced searching
• Fast grep - fgrep for quick searches
• Computations - expr for arithmetic evaluation
• Computations – bc, eval Command for complex calculations
• Argument Processing for input handling
• getopts Command for option parsing
• Using Arrays for data storage and manipulation

Advanced Edit – vi & sed

• vi - Mapping Key Combinations for custom shortcuts
• Mapping Control Keys for enhanced editing
• Using Abbreviations for efficiency
• Editing Many Files simultaneously
• Regular Expressions for pattern-based operations
• Global Insert for batch modifications
• Here document for multi-line input
• Batch Stream Editor - sed, sed delete, -d, sed print, -p, sed suppress, -n, sed quit, -q, sed file, -f, sed Multiple Input, sed for text processing
• Find and Replace for content modification
• sed Example for practical application

Text File Processing - awk

• The awk Programming Tool for data analysis
• Pattern Matching for selective processing
• Regular Expressions for advanced pattern matching
• Comparison Patterns for conditional operations
• Compound Patterns for complex conditions
• Range Patterns for interval-based processing
• Special Patterns for specific scenarios
• Built-in Functions for enhanced functionality
• Troubleshooting awk Scripts for reliability
• Passing Parameters to awk scripts for dynamic input
• Using Contains for substring matching
• printf Function for formatted output
• Computations for arithmetic operations
• Functions for custom logic
• substr for string manipulation
• length for string length determination
• Action Statements for script actions
• Control Flow Statements for logical control
• Arrays for data storage and retrieval
• Arrays with for Loops for iteration
• awk Examples for practical use cases