Shell Programming Training

Shell script elements

• Commands and comments
• Defining exit values

Conditional program execution

• Applying if and case statements
• Simplifying if logic with elif

Program loops and iteration

• Conditional looping with while and until
• Listing for loops

Testing files and directories

• Analysing attributes
• Checking file size and contents

Strings and patterns using [[ ]]

• Comparing strings
• Verifying the existence of a string
• Pattern matching and special characters

Debugging

• Redirecting standard error
• set commands for debugging

Positional parameters

• Passing and accessing parameters
• Manipulating parameters as groups

Shell variables

• Defining environment and local variables
• Specifying default values and error conditions

Arrays

• Creating and indexing arrays
• Processing array contents with special variables

Manipulating strings

• Extracting substrings
• Determining string length

Mathematics

• Arithmetic for and while loops
• Writing mathematical expressions: (( )), $(( )) and let

Function basics

• Functions vs. scripts
• Parameters and variables

Creating a function library

• Finding your library with PATH
• Dot . and source commands

Manipulating files and redirecting data

• Scripting file and directory management
• Unravelling the secrets of exec: opening and closing multiple files

Interacting with running processes

• Handling errors
• Processing external events
• Handling and sending signals: trap and kill

Accessing network servers

• Connecting to a network server
• Exchanging data with a network server

Ensuring environmental control

• Checking and modifying environment variables
• Using getopts to process command-line options

Handling user actions

• Accepting command-line arguments
• Employing select to create a menu interface
• Processing keyboard input