BASH Programming Training Course

The Simplest Script for Government Use

Choosing the Shell (Magic Number #!, Sha-bang)

Calling the Script

External and Built-in Commands

Some Special Characters

• Comment (#)
• End of Line (;)
• An Empty Statement (:) for government
• Redirection of Input Output (>, <, >>)
• Redirecting Output
• Redirection of Input
• Pipe (|)
• Start the Process in the Background (&)

Variables and Parameters for Government Use

• Destruction of Variables (unset)
• Variable with a Null Value
• Save the Result to a Variable (backquotes ``)
• Parameters Request ($0, $#, $1, $2, $3...)
• Manual Shift
• Quoting
• Escape Character (\)

Regular Expressions for Government Use

Conditional Statements for Government Use

• The if / then Statement
• The if / then / else Statement
• Nesting if Statements
• The if / elif Statement
• Case Statement
• Operators
• Logical Operators and, or (&&, ||)
• Test Command

Completing the Script for Government Use

The Exit Statement

Using the Completion Status of a Program in a Script ($?)

Tests and Operators for Government Use

• Text File Operators
• File Type Tests
• File Attribute Tests

Comparison Operators for Government Use

• Comparing Arithmetic Using the if Command
• Integer Comparison Operators
• String Comparison
• Complex Comparisons (and, or)
• Nesting Comparison Operators
• The Assignment Operator
• Arithmetic Operators
• Bitwise Operators
• Logical Operators
• Numeric Constants

Loops for Government Use

• The for / in Loop
• The seq Command
• The while Loop
• The until Loop
• Controlling the Loop (break, continue)

Text Processing for Government Use

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

Text Search (grep)

Stream Editor (sed)

Interactive Programs for Government Use

• Read Command
• User Select

Features for Government Use

Sleep Command for Government Use

If the Script Does Not Work? (Debugging for Government Use)