BASH Programming Training Course

The Simplest Script

Choosing the Shell (Shebang #!)

Executing the Script

External and Built-in Commands

Special Characters

• Comments (#)
• Line Termination (;)
• Null Statement (:)
• Input/Output Redirection (>, <, >>)
• Output Redirection
• Input Redirection
• Pipe Stream (|)
• Running Processes in the Background (&)

Variables and Parameters

• Variable Removal (unset)
• Variables with Null Values
• Assigning Results to Variables (Backticks ``)
• Parameter Arguments ($0, $#, $1, $2, $3...)
• Manual Shift
• Quoting
• Escape Characters (\)

Regular Expressions

Conditional Statements

• if/then
• if/then/else
• Nested if Statements
• if/elif
• case Statement
• Logical Operators
• AND/OR Operators (&&, ||)
• test Command

Script Completion

The exit Statement

Utilizing the Program Completion Status in Scripts ($?)

Tests and Operators

• File Operators
• File Type Tests
• File Attribute Tests

Comparison Operators

• Arithmetic Comparison Using if
• Integer Comparison Operators
• String Comparison
• Complex Comparisons (AND, OR)
• Nested Comparison Operators
• Assignment Operator
• Arithmetic Operators
• Bitwise Operators
• Logical Operators
• Numeric Constants

Loops

• for/in Loop
• seq Command
• while Loop
• until Loop
• Loop Control (break, continue)

Text Processing

• head, tail Commands
• Sort, Uniq, Expand, Unexpand
• Cut, Paste, Join, Wc, Tr

Text Search (grep)

Stream Editor (sed)

Interactive Programs

• read Command
• User Select

Functions

Sleep Command

Troubleshooting (Debugging)