BASH Programming Training Course

Basic Scripting

Shell Selection (Magic Number #!, Shebang)

Invoking Scripts

External vs. Built-in Commands

Special Characters

• Comments (#)
• Line Termination (;)
• Empty Statements (:)
• Input/Output Redirection (>, <, >>)
• Output Redirection
• Input Redirection
• Pipelines (|)
• Background Processes (&)

Variables and Parameters

• Unsetting Variables (unset)
• Variables with Null Values
• Storing Results in Variables (Backquotes ``)
• Parameter Access ($ 0, $ #, $ 1, $ 2, $ 3 ...)
• Manual Shifts
• Quoting
• Escape Characters (\)

Regular Expressions

Conditional Logic

• If / Then Statements
• If / Then / Else Statements
• Nested If Statements
• If / Elif Statements
• Case Statements
• Comparison Operators
• Logical Operators (AND, OR: &&, | |)
• The Test Command

Script Completion

The Exit Statement

Utilizing Program Completion Status within Scripts ($?)

Tests and Operators

• Text File Operators
• File Type Verification
• File Attribute Testing

Comparison Operators

• Arithmetic Comparisons via the If Command
• Integer Comparison Operators
• String Comparisons
• Complex Comparisons (AND, OR)
• Nested Comparison Operators
• Assignment Operators
• Arithmetic Operators
• Bitwise Operators
• Logical Operators
• Numeric Constants

Loops

• For / In Loops
• The Seq Command
• While Loops
• Until Loops
• Loop Control (break, continue)

Text Processing

• Head and Tail Commands
• Sort, Uniq, Expand, Unexpand
• Cut, Paste, Join, Wc, Tr

Text Search (grep)

Stream Editing (sed)

Interactive Program Features

• The Read Command
• User Selection

Additional Features

The Sleep Command

Troubleshooting Non-Functional Scripts (Debugging)