Shell Programming

Length: 3 days
CourseID: shell

Prerequisites:

Introduction to UNIX

Overview:

This course is intended for knowledgeable UNIX users with System Administrator duties that need to extend their UNIX knowledge and learn learn programming techniques.

Objectives:

Review some basic UNIX commands

Learn conditional statements

Learn loops

Learn arrays and string operators

Chapters:

Introduction

What is Shell Programming?	Benefits Of Shell Versus C Language
Getting Started

Conditional Statements

Quotes	Single Quotes
Double Quotes	Back Quotes
Command Substitution - Alternate Syntax	Escape Character (\)
Redirection	Regular Expressions
Filters	GREP / EGREP
SORT	WC
TR	CUT
ED	ED/SED Commands
SED	AWK Overview

The WHILE Loop

Types of VariablesNaming of Variables	Assigning a Value to a Variable
Using the Value of a Variable	Built-in Variables
User-Defined Variables	Positional Parameters (Variables)
Special Positional Parameters	Variables Read From Input
The READ command	The SET and EXPORT Commands
Integer Variables	The TYPESET Command
Using LET for Arithmetic Expressions	Enclosing a Variable Name Within Braces - '{}

The CASE Statement

Exit (return) Status	Determining the Exit Status of a Command
The IF Statement	The EXIT Command
The TEST Command	The TEST Command - The '[' Syntax
The TEST Command - Numeric Comparisons	The TEST Command - File/String Attributes
The IF-THEN-ELSE Statement	The Nested IF Statement
The IF-THEN-ELIF Statement	The "&&" and "\|\|" Conditional Operators
Debugging A Shell Program	The SET Command
Documenting a Shell Program

Miscellaneous Other I/O Topics

The WHILE Loop	The BREAK Command
The SHIFT Command	The CONTINUE Command
The TRUE and FALSE Commands	The FOR loop

Arrays and String Operators

The CASE Statement	The SELECT Loop
FUNCTIONS	The RETURN Command