SHELL PROGRAMMING
AND ADVANCED LINUX TOOLS OUTLINE

UNIX PROCESSES

What is a Process?
Process Structure
The ps Utility
Options to the ps Utility
Background Commands (&)
Killing Background Processes
Redirecting the Standard Error

GETTING STARTED

What is a Shell?
Running Scripts
Specifying the Script's Interpreter
The PATH Environment Variable
Sub-shells

VARIABLES

Shell Variables
The read Command
The export Command
The Shell Environment
Variable Substitution
Command Substitution

THE LOGIN PROCESS

The Login Process
The System Profile Script
Your .profile Script
The . Command

CONDITIONAL STATEMENTS

The Exit Status of Commands
Command Line Examples
The test Command
The if-then-else Construct
The elif Construct
case Statements

LOOPS

The for Loop
The while Loop
Reading Lines From Files
Using Arrays with Loops

SPECIAL VARIABLES

$$ - PID of Shell
Command-Line Arguments
$# - Number of Arguments
$* - All Arguments
The shift Command
The set Command
Getting Options

QUOTING MECHANISMS

Single vs. Double Quotes
What is a Here Document?
Using a Here Document
Here Document Quoting
Ignoring Leading Tabs

FUNCTIONS

Shell Functions
Passing Arguments to Functions
Returning Values from Functions
Function Libraries

ADVANCED PROGRAMMING

Shell Arithmetic
The select Statement
Terminal Independence in Scripts
The eval Command

DEBUGGING TECHNIQUES

Using echo
Using Standard Error
Options for Debugging
Script Tracing
Conditional Debugging

SHELL IPC

Co-processes
The print and read Commands
Signals
The trap Command
Named Pipes
The wait Command


INTRODUCTION TO AWK

How awk Programs Work
Running awk Programs

AWK PATTERNS

Summary and Patterns
BEGIN and END
Expressions
String-Matching Patterns
Extended REs in awk
Range Patterns

AWK ACTIONS

awk Actions
Expressions
Operators
Flow Control
More Flow Control
The next, break, continue, and exit statements
Built-in Variables

AWK INPUT AND OUTPUT

Formatted Output with printf
Output into Files
Output into Pipes
Input Separators
Multi-Line Records
The getline Function
More getline
Passing Parameters into a Script

AWK FUNCTIONS

Built-In Arithmetic Functions
Built-In String Functions
More String Functions
User Defined Functions
Local Variables


AWK ARRAYS

Associative Arrays
The Array for Statement
The Array in Operator
Deleting Array Elements
The Split Function
Multi-Dimensional Arrays
Command Line Parameter Passing